SL900A-ASWB_技术文档

SL900A

EPC Class 3 Sensory Tag Chip - For

Automatic Data Logging

The SL900A is an EPC global Class 3 sensory tag chip optimized

for single-cell and dual-cell, battery-assisted smart labels with

sensor functionality. The chip is ideal for applications using thin

and flexible batteries but can also be powered from the RF field

(electromagnetic waves from an RFID reader).

General Description

The chip has a fully integrated temperature sensor with a typical

nonlinearity of 0.ꢀ5C over the specified temperature range.

The external sensor interface provides a flexible way of adding

additional sensors to the system and supports up to 2 external

sensors.

Ordering Information and Content Guide appear at end of

datasheet.

Key Benefits & Features

The benefits and features of SL900A, EPC Class 3 Sensory Tag

Chip - For Automatic Data Logging are listed below:

Figure 1:

Added Value of using SL900A

Benefits

Versatile temperature and data logging

Worldwide EPC compliant

Features

High Temperature Range: -40°C to +12ꢀ°C

Frequency: 860 to 960 MHz

Battery supply: 1.ꢀV or 3V

Works fully passive or in BAP mode

Data logging from:

Programmable logging modes with various sensors

• On-chip temperature sensor

• 2 external sensors

Works with EPC readers

EPC Class 1 and Class 3 Compliant

Energy harvesting from reader field

Real-time clock for data logging

External sensor interrupt capability

Serial peripheral interface

Provides supply for external sensors

Autonomous data logging with timestamp

Sensor alert function

Supports fast communication via SPI

Storage for up to 841 events with timestamps

Alert for shelf life expiration

On-chip 9k bit EEPROM

Integrated dynamic shelf life calculation

Advanced logging with 4 user-selectable limits

Programmable sensor limits

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 1

Package Options

The available SL900A package options are:

• 16-pin QFN (ꢀ x ꢀ mm)

• Tested wafer (8”)

Applications

The SL900A device is ideal suited for:

• Monitoring and tracking of temperature-sensitive

products

• Temperature monitoring of medical products

• Pharmaceutical logistics

• Monitoring of fragile goods transportation

• Dynamic Shelf Life applications

• RFID to SPI interface

Block Diagram

The functional blocks of this device for reference are

shown below:

Figure 2:

SL900A Block Diagram

V_BAT

EXT1

Power

Management

Temperature

Sensor

V_DD

1.5V

or 3V

V_SS

EXT2

External

Sensor

Front-End

V_POS

V_SSA

Battery Voltage

EXC

V_REF

860 - 960 MHz

AFE

Processing

Digital Control

ANT

EPC Gen2

Class 3

MUX

D_IN

D_OUT

SCLK

SEN

(cool-Log™)

SPI

Port

(Slave)

FIFO

10-Bit A/D

Converter

MEAS

1152 x 8 Bit

EEPROM

Oscillator

with RTC

ANA TEST

DIGI TEST

SL900A

SL900A Block Diagram: Basic block diagram of SL900A

SL900A – 2

ams Datasheet: 2014-May-06 [v1-01]

Pin Assignment

The SL900A pin assignments are described below.

Pin Assignment

Figure 3:

Pin Layout

16

15

14

13

12

11

10

9

1

2

3

4

V_POS

D_OUT

V_SSA

D_IN

SL900A

ANT

SCLK

SEN

DIGI_TEST

5

6

7

8

Figure 4:

Pin Description

Pin Number

Pin Name

Description

V

1

RF rectifier output

POS

V

2

3

4

ꢀ

6

7

Chip substrate ground – connect to antenna ground

Antenna coil

SSA

ANT

DIGI_TEST

Test input – must be left open

V

Reference voltage output (Vo2)

REF

EXT1

EXT2

Analog input for external sensor

Chip substrate ground – connect to negative battery

V

8

SS

terminal. Recommended to connect to V

!

SSA

9

SEN

Enable input for the SPI interface

SPI clock

10

11

SCLK

D

SPI data input

IN

D

12

SPI data output

OUT

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 3

B a r e D i e P a d L a y o u t

Pin Number

Pin Name

Description

V

13

14

Positive supply input

BAT

MEAS

EXC

Test pin for use during test – must be left open

Supply voltage for the external sensors or a AC signal source

for external sensors

1ꢀ

16

ANA-TEST

Analog test pin – must be left open

Pin Description: This table shows a detailed pin description of the SL900A.

Bare Die Pad Layout

Figure 5:

Pad Location Diagram

SL900A – 4

ams Datasheet: 2014-May-06 [v1-01]

Bare Die Pad Layout

Figure 6:

Pad Parameters

Pad name X position (μm) Y position (μm) Pad window (μm)

Type

V

77.ꢀ

2040.ꢀ

1787.ꢀ

1098.ꢀ

223.ꢀ

8ꢀ x 8ꢀ

Analog Output

REF

EXT1

EXT2

Analog Input/Output

Supply

V

SS

S

1822.ꢀ

200ꢀ.ꢀ

2271.ꢀ

24ꢀ4.ꢀ

26ꢀ3.ꢀ

26ꢀ7.ꢀ

2648.3

26ꢀ7.ꢀ

77.ꢀ

8ꢀ x 8ꢀ

EN

Digital Input

SCLK

SDATAI

77.ꢀ

SDATAO

E_SDATAO

77.ꢀ

Digital Output

Test Pad

82.ꢀ

V

27ꢀ.ꢀ

ꢀ09.1ꢀ

2144.ꢀ

2327.ꢀ

2ꢀ10.ꢀ

Supply

BAT

MEAS

EXC

Test Pad

Analog Output

Test Pad

ANA_TEST

V

Analog Output

POS

V

2292

1396

1177

9ꢀꢀ

2689.ꢀ

2696

8ꢀ x 8ꢀ

Supply

Radio-frequency Pad,

Test Pad

SSA

ANT2

ANT1

See RF pad drawing

8ꢀ x 8ꢀ

2694

DIGI_TEST

2707.ꢀ

Pad locations: Pad locations are measured from lower left chip edge to pad centre.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 5

A b s o l u t e M a x i m u m R a t i n g s

Stresses beyond those listed under “Absolute Maximum

Absolute Maximum Ratings

Ratings” may cause permanent damage to the device. These are

stress ratings only. Functional operation of the device at these

or any other conditions beyond those indicated under

“Operating Conditions” is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect

device reliability.

Figure 7:

Absolute Maximum Ratings (Operating free-air temperature range, unless otherwise noted)

Parameter

Min

Max

Units

Comments

All voltage values are with respect to

Input Voltage Range

-0.3

3.7

V

substrate ground terminal V

SS

Maximum Current V , ANT

100

2

mA

kV

V

POS

ESD Rating, HBM (all pins except ANT)

ESD Rating, HBM (RF input pin ANT)

Maximum Operating Virtual Junction

ꢀ00

+1ꢀ0

°C

Temperature, T

J

Storage Temperature Range, T

-6ꢀ

+1ꢀ0

+260

°C

stg

Lead Temperature (soldering, 10 sec.)

Absolute Maximum Ratings: This figure shows the absolute maximum ratings of the SL900A.

This integrated circuit can be damaged by ESD. We recommend

that all integrated circuits are handled with appropriate

precautions. Failure to observe proper handling and installation

procedures can cause damage. ESD damage can range from

subtle performance degradation to complete device failure.

Electrical Discharge Sensitivity

Precision integrated circuits may be more susceptible to

damage because very small parametric changes could cause

the device not to meet the published specifications. RF

integrated circuits are also more susceptible to damage due to

use of smaller protection devices on the RF pins, which are

needed for low capacitive load on these pins.

Operating Conditions

Figure 8:

Operating Conditions

Symbol

Parameter

Min

1.2

Typ

Max

3.6

Units

V

Input Supply Voltage

1.ꢀ

V

BAT

T

Operating ambient temperature range

-40

+12ꢀ

°C

A

SL900A – 6

ams Datasheet: 2014-May-06 [v1-01]

Elec trical Charac teristics

All limits are guaranteed. The parameters with min and max

values are guaranteed with production tests or SQC (Statistical

Quality Control) methods.

Electrical Characteristics

T = -40°C to +12ꢀ°C, V = 1.ꢀV, unless otherwise noted.

A

BAT

(1)

Typical values are at T = 2ꢀ°C

.

A

Figure 9:

Electrical Characteristics

Symbol

Parameter

Conditions

Min

Typ

Max Units

V

T = 2ꢀ°C

Operating Input Voltage

1.2

3.6

V

BAT

A

V

T = 2ꢀ°C

Minimum Start-Up Input Voltage

1.3

BAT(SU)

A

Temperature

conversion,

I

Operating Current into V

200

2ꢀ0

3ꢀ0

μA

BAT-OP1ꢀ

BAT

V

=1.ꢀV

BAT

Temperature

conversion, V =3V

I

Operating Current into V

290

BAT-OP30

BAT

V

= 1.ꢀV; timer

BAT

I

Quiescent Current into V

1.6

0.ꢀ

μA

BAT-Q

BAT

running

V = 1.ꢀV

BAT

I

Shutdown Current into V

BAT-SD

BAT

In electromagnetic

field

I

Maximum Current from V

POS

200

EXT

In electromagnetic

field

V

limiter point

POS

3.4

V

POS-l

Measured at

900MHz, QFN

package for PCB

assembly

31-j3

20

ANTI-QFN Antenna pad impedance

Ω

Measured at

900MHz, bare die for

inlay assembly

9-j33

0

ANTI-DIE

ANTS

Antenna pad impedance

Antenna pad sensitivity

Ω

Measured at

900MHz, battery

assisted mode

-1ꢀ

dBm

V

= 1.ꢀV

= 3V

0.4

1

V

BAT

Voltage Input Threshold, Low

(SEN, SCLK, DIN)

V

IL

= 1.ꢀV

= 3V

1

Voltage Input Threshold, High

(SEN, SCLK, DIN)

V

IH

2.1

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 7

E l e c t r i c a l C h a ra c t e r i s t i c s

Symbol

Parameter

Conditions

Min

Typ

Max Units

V

1mA

= 1.ꢀV, I

=

BAT

DOUT

V

4ꢀ0m

300m

V

SS

Voltage Output Threshold, Low

V

OL

D

OUT

V

1mA

= 3V, I

=

BAT

DOUT

V

SS

V

= 1.ꢀV, I

DOUT

BAT

V

1

BAT

-1mA

Voltage Output Threshold, High

V

OH

D

OUT

V

= 3V, I =

DOUT

BAT

V

2.7

BAT

-1mA

V

= 1.ꢀV

1

ꢀ

MHz

5C

BAT

f

SCLK serial data clock

SCLK

= 3V

f

Carrier Frequency

860

-20

960

60

c

T

Temperature Sensor Range

S-R

Extended temperature sensor

range with reduced accuracy

T

-40

+12ꢀ

5C

S-R EXT

T

Inside T

Temperature sensor nonlinearity

Temperature Sensor Accuracy

Measurement interval

0.ꢀ

1

S-NL

S-R

T

5C

S-A

S-R

t

Programmable

1

32,768

Sec

sens

t

Real-Time Clock, Interval

1

RTC-I

Over specified T

temperature range

S-R

t

Real-Time Clock, Accuracy

-3

+3

%

RTC-A

Real-Time Clock, Calibration

Accuracy

t

T = 3ꢀ°C

-0.2

+0.2

RTC-CA

A

SL900A – 8

ams Datasheet: 2014-May-06 [v1-01]

Shor t Description

Symbol

Parameter

Conditions

Min

Typ

Max Units

t

V

=1.3V ~ 3V

BAT

Real-time Clock, Accuracy

3

%

RTC-B

= 1.2V~1.3V;

BAT

Real time clock, Accuracy

-7

+ꢀ

%

RTC-C

3V~3.6V

EW

T = 2ꢀ°C

EEPROM Erase/Write Cycles

EEPROM Data Retention Time

EEPROM Erase/Write Speed

100,000

Cycles

Years

ms

CYC

A

t

T = 12ꢀ°C

20

7

DR

A

t

7.ꢀ

E/W

EXC internally

connected to V

for ext. sensor

supply

BAT

r

EXC pin output resistance

400

200

Ω

EXC

External sensor interface pads

r

EXT

resistance (EXT1, EXT2, V

)

REF

Note(s) and/or Footnote(s):

1. Limits are 100% production tested at T_A= 3ꢀ°C. Limits over the operating temperature range are guaranteed by design.

The SL900A is designed for use in smart active labels (SAL),

semi-passive labels and passive labels. Smart active labels are

defined as thin and flexible labels that contain an integrated

circuit and a power source. SAL includes in its definition both

“fully active” smart labels, and semi-active smart labels, also

known as battery-assisted back-scattered passive labels, both

of which enable enhanced functionality and performance over

passive labels. The IC includes sensor functionality and logging

of sensor data (see Figure 10 below).

Short Description

The SL900A is operating at 860 to 960 MHz and is fully EPC

global Class 1 compliant. The chip is supplied from a single-cell

battery of typically 1.ꢀV, or from a dual cell battery (3V). The

on-chip temperature sensor and real-time clock (RTC)

accommodate temperature data logging.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 9

S h o r t D e s c r i p t i o n

Supply Arrangement

The SL900A is supplied from either the battery or through the

electromagnetic waves from a reader. The device is normally

supplied from the battery unless there is no battery attached

(passive label), or when the battery is drained.

Figure 10:

Block Diagram

V_BAT

EXT1

Power

Management

Temperature

Sensor

V_DD

1.5V

or 3V

V_SS

EXT2

External

Sensor

Front-End

V_POS

V_SSA

Battery Voltage

EXC

V_REF

860 - 960 MHz

AFE

Processing

Digital Control

ANT

EPC Gen2

Class 3

MUX

D_IN

D_OUT

SCLK

SEN

(cool-Log™)

SPI

Port

(Slave)

FIFO

10-Bit A/D

Converter

MEAS

1152 x 8 Bit

EEPROM

Oscillator

with RTC

ANA TEST

DIGI TEST

SL900A

Analog Front End (AFE)

The analog front end is designed according to EPC Gen 2. The

forward link (reader to tag) is amplitude modulated and the

backward link (tag to reader) is amplitude modulated (load

modulation is used).

Processing and Digital Control

The SL900A is fully EPC Class 1 compliant, with additional

custom commands for extended functions. The maximum

transponder to interrogator data rate according to Class

1/Gen.2 is 640 kbit/s. The maximum interrogator to

transponder data rate is 160 kbit/s.

Figure 11:

Supported Data Rates

Data Rate

Min

Max

Interrogator to transponder

Transponder to interrogator

40 kbit/s

ꢀ kbit/s

160 kbit/s

640 kbit/s

SL900A – 10

ams Datasheet: 2014-May-06 [v1-01]

Shor t Description

Serial Interface (SPI)

The integrated serial interface (SPI) can be used to initialize the

chip and to set the parameters. The logging procedure can be

started and stopped with the SPI. The SPI bus can also be used

for the communication between a microcontroller that is

attached to the SL900A and the RFID reader.

Real-Time Clock (RTC)

The on-chip real-time clock (RTC) is started through the START

LOG command in which the start time is programmed in UTC

format. The interval for sensing and data logging can be

programmed in the range from 1 second up to 9 hours. The

accuracy of the timer is 3%. The timer oscillator is calibrated

at 3ꢀ 5C within 0.2%.

Temperature Sensor

The on-chip temperature sensor can measure the temperature

in the range from -205C to 605C with a typical accuracy of 15C.

The full temperature range of -405C to +12ꢀ5C has a reduced

accuracy.

External Sensors

The on-chip external sensor front end provides a flexible

interface for analog external sensors. It has an auto-range and

interrupt function. It supports various types of analog sensors

from pressure, humidity, temperature, light …

Analog to Digital Converter

The chip has an integrated 10-bit analog to digital converter

with selectable voltage references. It is used for conversion of

temperature, external sensors and battery voltage.

External Sensor Interrupt

The external sensor inputs EXT1 and EXT2 can be used for

event-triggered logging. In this mode, the logging is not

triggered in predefined time intervals from the internal timer,

but can be triggered externally, either with a sensor, switch or

a microcontroller.

The interrupt source can be the EXT1, EXT2 input or both, were

the EXT1 input has the higher priority. The user application can

select which measurements are triggered by the interrupt

event.

In the interrupt mode, the sensor value is stored together with

the 32-bit real time clock value. For a correct real-time clock

value, the correct Start time has to be supplied. The interrupt

mode is started with the START LOG command and the correct

setting in the registers (SET LOG MODE command).

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 11

S h o r t D e s c r i p t i o n

Data Protection

Additional to the Gen2 lock protection, the SL900A offers

read/write protection using 3 password sets for 3 memory

areas. Each 32-bit password is divided into 2 16-bit passwords,

where the lower 16 bits are reserved for the Write protection

and the higher 16 bits are reserved for the Read/Write

protection.

Shelf Life

The SL900A device has an integrated shelf life algorithm that

can dynamically calculate the remaining shelf life of the

product. It has an automatic alarm function for the shelf life

expiration. This can be used to directly drive a LED or as an

interrupt for an external microcontroller.

Memory arrangement

The SL900A device has an integrated 9kbit EEPROM. It is

organized into ꢀ memory banks shown below.

Figure 12:

Memory Arrangement

Memory Bank

Bank Size (bits)

Comments

System parameters like calibration data and log

parameters

SYSTEM

ꢀ12

RESERVED

EPC

64

Access and Kill password

PC and EPC value

144

Unique identifier – programmed and locked during

production

TID

80

USER

8416

User and measurement data

SL900A – 12

ams Datasheet: 2014-May-06 [v1-01]

System D escription

Figure 14 shows the different states and their interactions.

Figure 22 shows the command overview.

System Description

Initializing the Chip

A virgin chip (not initialized) can be initialized either through

the SPI port or through the electromagnetic field from a reader

in the standby mode. The power source is either from a battery

(V ) or extracted from the RF field via the AFE circuit. After

BAT

the initializing procedure, the chip will enter the ready mode.

Power Modes

Ready Mode

In the ready mode, all parameters can be set, read and changed

through a reader with the appropriate passwords.

Active Mode

In active mode, the real-time clock (RTC) is running, the desired

parameters are set, and the on-chip temperature sensor is in

standby.

Logging Mode

A log flag from the timer will enable the logging mode in which

the sensor and the A/D converter will be activated, and the

measured value will be stored in the EEPROM together with the

time of the event. If the external sensor flag is set, the external

sensors will also be activated and the measured data stored.

The A/D converter can be multiplexed between internal

temperature sensor, external sensors or battery voltage. After

the event, the chip will return to the active mode.

Interrupt Mode

In the interrupt mode, the external sensor interrupt block is

running with minimal power consumption. When the external

sensor value exceeds a specified threshold, the chip goes into

the logging mode where the selected sensor values and real

time of the event are stored to the EEPROM.

Stand-by Mode

In passive mode, all blocks in the chip are turned off and only

the leakage current is flowing. When the label enters an RF field,

it will go from Stand-by mode to Ready mode. If the SEN pin

rises high, the chip will go from the Stand by mode to the serial

mode

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 13

S y s t e m D e s c r i p t i o n

Figure 13:

Modes of Operation

Mode

Description

IBAT (Typ.) Power from AFE

In passive mode the chip is turned off and only the

leakage current is flowing

Stand-by

Serial

0.1 μA

ꢀ0 μA

2 μA

No

Yes

No

Enables initializing and executing of all commands via

the SPI bus

Chip is initialized and all commands can be executed

via the reader

Ready

• RTC running

• Sensor standby

Active

• RTC running

• External sensor minimum supply

Interrupt

2.ꢀ μA

• Sensor reading (on-chip temperature sensor,

battery voltage level and/or external sensor

through the MMI pin)

Logging

180 μA

No

• Measured data stored in EEPROM

• RTC time stored in EEPROM

State Diagram

Figure 14:

State Transition Diagram

SPI REQUEST:

ALL

LOG-TIMER or

IRQ

SPI Stop

logging

SEN=0

Serial

SPI Start

Logging

SEN=1

Active or

Interrupt

Logging

Stand-by

SEN=1

SEN=0

START-LOG

END-LOG

RF on

LOG-FINISHED

Ready

READER REQUEST:

ALL EPC standard

COMMANDS

SET PASSWORD

GET MEASUREMENT SETUP

SET PASSIVE

RF off

Temperature

measurement.

Battery

measurement.

Limits comparison.

Shelf life.

External sensor

measurement.

Log to EEPROM.

READER REQUEST:

ALL COMMANDS

GET LOG STATE

GET CALIBRATION DATA

GET BATTERY LEVEL

OPEN AREA

GET SENSOR VALUE

SL900A – 14

ams Datasheet: 2014-May-06 [v1-01]

System D escription

Data Protection

Additional to the Gen2 lock protection, the SL900A offers

read/write protection using 3 password sets for 3 memory

areas. The System area is protected by the System password,

the Application area is protected by the Application password,

and the Measurement area is protected by the Measurement

password. Each 32-bit password is divided into 2 16-bit

passwords, where the lower 16 bits are reserved for the Write

protection and the higher 16 bits are reserved for the

Read/Write protection.

The password can be set either with the custom RFID command

SET PASSWORD, or through the SPI, by writing the password to

the password locations.

The password protection is activated immediately after the SET

PASSWORD command. In case the passwords are written with

the SPI interface, the protection is activated when the

transponder re-enters an RF field.

Password protection does not block any read/write operation

on the SPI interface; it is active only for the RFID interface.

Figure 15:

Password Storage in System Memory

Address

Data

Function

0x000

0x001

0x002

0x003

0x004

0x00ꢀ

0x006

0x007

0x008

0x009

0x00A

0x00B

System Password [31:24]

System Password – read/write protect

System Password - write protect

System Password [23:16]

System Password [1ꢀ:8]

System Password [7:0]

Application Password [31:24]

Application Password [23:16]

Application Password [1ꢀ:8]

Application Password [7:0]

Measurement Password [31:24]

Measurement Password [23:16]

Measurement Password [1ꢀ:8]

Measurement Password [7:0]

Application Password – read/write protect

Application Password - write protect

Measurement Password – read/write protect

Measurement Password - write protest

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 15

S y s t e m D e s c r i p t i o n

Data Log Functions

The SL900A device supports various flexible data log formats.

The data log format depends on the Logging form. The data log

formats are defined in Figure 23.

The Logging form is set with the SET LOG MODE command and

is stored in “Logging form [2:0]” (SPI address 0x026) bits in the

EEPROM.

Figure 16:

Supported Logging Formats

Bit 2

Bit 1

Bit 0

Logging From

Description

All values are stored to the measurement area. No

additional time information is stored to the measurement

area.

0

Dense

All values that are out of the specified limits are stored to

the measurement area. Additional to the sensor value,

also the measurement number is stored, so the

All values out of

limits

0

1

0

1

0

1

0

1

application can reconstruct the time-sensor points.

Only the crossing point of each limit boundary is stored.

Additional to the sensor value, also the measurement

number is stored, so the application can reconstruct the

time-sensor points.

Limits crossing

IRQ, EXT1

Interrupt triggered on the EXT1 external sensor input. At

each trigger event the selected sensor values are stored.

Additional to the sensor values, also the real-time clock

offset is stored.

Interrupt triggered on the EXT2 external sensor input. At

each trigger event the selected sensor values are stored.

Additional to the sensor values, also the real-time clock

offset is stored.

IRQ, EXT2

Interrupt triggered on the EXT1 and EXT2 external sensor

input. At each trigger event the selected sensor values are

stored. Additional to the sensor values, also the real-time

clock offset is stored.

IRQ, EXT1, EXT2

When the “IRQ + timer enable” bit (Initialize command, SPI

address 0x02A) is set to 1, the logging will be triggered on the

selected time interval (timer) and also on an interrupt from

external sensor1, sensor 2 or both – depending on the selected

logging mode.

The Storage rule bit defines what happens when the logging

area in the EEPROM is full.

SL900A – 16

ams Datasheet: 2014-May-06 [v1-01]

System D escription

Figure 17:

Storage Rule

Bit

Storage Rule

Description

When the logging area in the EEPROM is full, the chip does not store any new

sensor data to the EEPROM, but it will still increment the measurement counter

and RTC.

0

Normal

Rolling

When the logging area is full, the chip continues with writing new sensor data

to the EEPROM form the beginning of the logging area. Thus the chip

overwrites the old stored data and increments the “Number of memory

replacements [ꢀ:0]” field in the System status group.

1

Limits Counter

The Limits counter can be used as an advanced alarm

mechanism. It is enabled in all log formats and it will display

the cumulative number of measurements that are outside

limits. The application does not have to read the whole EEPROM

content in order to determine if the temperature limits have

been exceeded, just the Limits counter block. The Limits

counter block can be read out with the GET LOG STATE

command.

The system uses 4 limits that can be set by the user:

• Extreme upper limit

• Upper limit

• Lower limit

• Extreme lower limit

There is a dedicated 8-bit counter for each of the 4 limits in the

Limits counter block. The appropriate counter will increment

each time a sensor value is outside a limit.

The user can select which sensor will be used in the limits

comparison. The internal temperature sensor is selected by

default. Other sensors can be selected with the SET SFE

PARAMETERS command with the “Verify sensor ID[1:0]” field

(SPI address 0x018):

Figure 18:

Modes of Operation

Verify Sensor ID Bit 1 Verify Sensor ID Bit 0 Sensor Selected for Limits Comparison

0

1

0

1

0

1

Internal temperature sensor - DEFAULT

External sensor 1

External sensor 2

Battery voltage

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 17

S y s t e m D e s c r i p t i o n

Logging Timer

The SL900A device has an integrated RC oscillator that is

calibrated to 1024Hz. This oscillator drives the logging timer.

The logging timer resolution is 1 second. The maximum period

is 9.1 hours (32768 seconds). The logging interval is

programmed with the SET LOG MODE command.

The measurement real time is derived from 4 parameters - the

Start time (ST), the Delay time (DT), the log interval (LT), and

the # of the measurement (NM). This value has to be calculated

in the reader by the equation:

Real time = ST+DT+LT*NM

Delay Time

The SL900A supports delayed start of the logging procedure.

The Delay time has a resolution of 8 minutes - 32 seconds (ꢀ12

seconds) and a maximum value of ꢀ82 hours (12 bits). The delay

time value is set with the Initialize command, while the Delay

time counter starts counting when the device receives the

START LOG command.

The delay time can also be disabled and an external push button

can be used for starting the logging procedure.

Analog to Digital Conversion

The chip has an integrated analog to digital converter with

10-bit resolution and selectable voltage references. By default,

the references are selected as: Vo1 = 0V and Vo2 = 310mV. This

results in a voltage input range of 310mV ~ 620mV, for the

temperature conversion this is -89.35C ~ +94.65C.

The voltage references are individually selectable in ꢀ0mV steps

with a fine adjustment for offset calibration. Additionally, the

Vo1 reference voltage can be tied directly to ground if the bit

“gnd_switch” in the SET CALIBRATION DATA command is set to

1 (SPI address 0x012).

SL900A – 18

ams Datasheet: 2014-May-06 [v1-01]

System D escription

Figure 19:

AD Reference Voltages

Calib. Code

0b000

Vo1

Vo2

160mV

210mV

260mV

310mV

360mV

410mV

460mV

ꢀ10mV

260mV

310mV

360mV

410mV

460mV

ꢀ10mV

ꢀ60mV

610mV

0b001

0b010

0b011

0b100

0b101

0b110

0b111

The Vo2 voltage defines the lower temperature limit for the

temperature conversion – note that normal operation is not

guaranteed below -40 5C.

Figure 20:

Theoretical Lower Temperature Limit

Vo2

Low. Temp. Lim.

-118.9 5C

-89.3 5C

260mV

310mV

360mV

410mV

460mV

ꢀ10mV

ꢀ60mV

610mV

-ꢀ9.6 5C

-29.0 5C

0.3 5C

29.3 5C

ꢀ9.0 5C

88.7 5C

The voltage difference between the Vo2 and Vo1 references

define the resolution and temperature range.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 19

S y s t e m D e s c r i p t i o n

Figure 21:

Temperature Conversion Resolution and Range

Vo2 - Vo1

310mV (default)

ꢀ0mV

Resolution

Range

0.18 5C

0.029 5C

0.0ꢀ8 5C

0.086 5C

0.116 5C

0.14ꢀ 5C

0.1ꢀ1 5C

0.174 5C

0.203 5C

0.209 5C

0.232 5C

183.9 5C

29.7 5C

100mV

ꢀ9.3 5C

1ꢀ0mV

88.0 5C

200mV

118.6 5C

148.3 5C

1ꢀ4.2 5C

177.9 5C

207.6 5C

213.ꢀ 5C

237.2 5C

2ꢀ0mV

260mV

300mV

3ꢀ0mV

360mV

400mV

Example:

Vo1 = 310mV, Vo2 = 410mV -> A/D conversion temperature

range = -29.35C ~ 30.0 5C.

Temperature resolution = 0.0ꢀ8 5C.

The converted voltage can be calculated from the following

equation:

Vo2 – Vo1

---------------------------

V_SENS= code ⋅

+ Vo2

1024

SL900A – 20

ams Datasheet: 2014-May-06 [v1-01]

System D escription

Temperature Conversion

The calibration data does not have to be included in the

temperature conversion equation. The temperature value

calculation is dependent on the selected voltage references

(See “Analog to Digital Conversion” on page 18.):

∗

T ⋅ (°C) = code Resolution – Low ⋅ temp ⋅ limit

By default (factory setting), the voltage references are set: Vo1

= 0V, Vo2 = 310mV. This yields a theoretical temperature

conversion range of -89.35C ~ +94.65C. The temperature

conversion equation for this setting is:

∗

T ⋅ (°C) = code 0.18°C – 89.3°C

LSB = 0.18°C

Offset = (–89.3)°C

When the reference voltages are set to some other value, the

following equation needs to be used for temperature

conversion:

Vo2[mV] ⋅ (code + 1024) – code ⋅ Vo1[mV]

-----------------------------------------------------------------------------------------------------------------

T ⋅ (°C) =

– 273.15

1024 ⋅ 1.686

The Vo1 and Vo2 in the above equation have to be in mV.

Battery Voltage Conversion

The battery voltage conversion is dependent on the initial

battery voltage (1.ꢀV or 3V) and on the selected voltage

references (See “Analog to Digital Conversion” on page 18.). The

conversion equations with factory selected voltage references

(Vo1 = 0V, Vo2 = 310mV) are:

For 1.ꢀV battery, the equation is:

• V = code*0.8ꢀmV + 873mV

• LSB = 0.8ꢀmV

• Offset = 873mV

For 3V battery:

• V = code*1.6ꢀmV + 1.69V

• LSB = 1.6ꢀmV

• Offset = 1.69V

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 21

Commands

Some commands can be password protected by 3 different

passwords: System password (S), Application password (A) or

Measurement password (M).

Commands

Figure 22:

EPC Gen2 and Cool-Log™ Command Overview

Allowed in Modes

Command

Code

Mode

Change

Security

Level

#

Command

Definition

EPC Gen2

01

02

03

04

0ꢀ

06

07

QueryRep

ACK

0b00

0b01

-

√

-

No

Yes

No

/

anticollision round

command

EPC Gen2

anticollision round

command

EPC Gen2

anticollision round

command

Query

0b1000

0b1001

0b1010

0xC0

EPC Gen2

anticollision round

command

QuaryAdjust

Select

EPC Gen2

anticollision round

command

EPC Gen2

anticollision round

command

NAK

Request for a new

16-bit random

number

Req_RN

0xC1

Reads the selected

block in the

specified memory

bank

08

09

Read

Write

0xC2

0xC3

-

√

-

No

A or M

Writes the selected

block in the

specified memory

bank

Kills the transponder

– no RFID access is

possible after this

command (SPI

10

Kill

0xC4

-

√

-

No

/

remains active)

SL900A – 22

ams Datasheet: 2014-May-06 [v1-01]

Co mmands

Allowed in Modes

Command

Code

Mode

Change

Security

Level

#

Command

Definition

Locks the selected

memory banks

11

12

Lock

0xCꢀ

0xC6

-

√

-

No

/

Puts the transponder

to the secured state

Access

Writes the selected

block in the

specified memory

bank

13

14

BlockWrite

BlockErase

0xC7

0xC8

-

√

-

No

A or M

Erases the selected

block in the

specified memory

bank

Note: The cool-Log commands are defined as EPC custom commands. All custom commands have a 16-bit

st

command code, where the 1 command code is defined as 0xE0, the second command code is in the

table below.

Sets the passwords

to EEPROM

1ꢀ

16

Set Password

Set Log Mode

0xA0

0xA1

-

√

-

No

S, M or A

S

Sets logging mode

Sets the

Set Log

Limits

measurement limits

for limits logging

mode

17

0xA2

-

√

-

No

S

Reads 4 system

blocks - Start time,

Log limits, Log

mode, and Delay

time + application

area size

Get

measurement

setup

18

0xA3

-

√

-

No

S

Sets parameter for

the External sensor

front end

Set SFE

parameters

19

20

0xA4

0xAꢀ

-

√

-

No

S

Sets the calibration

data for the

temperature sensor

and timer

Set

Calibration

Data

Stops the log

procedure and

returns the chip to

Standby mode

21

End Log

0xA6

-

√

-

√

-

Yes

S

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 23

Commands

Allowed in Modes

Command

Code

Mode

Change

Security

Level

#

Command

Definition

Starts the timer and

the selected log

procedure

22

23

24

Start Log

0xA7

0xA8

0xA9

-

√

-

Yes

No

S

Gets the log state of

the chip

Get Log State

√

Get

calibration

data

Reads the internal

and external

calibration data

Get Battery

level

Measures the

battery voltage

2ꢀ

26

0xAA

0xAB

-

√

-

No

/

Set the shelf life

parameters

Set Shelf Life

Initializes the chip

and sets the

27

28

Initialize

0xAC

0xAD

-

√

-

No

S

/

aapplication area

size and the logging

delay

Measures the

specified sensor –

temperature, ext.

sensor1 or ext.

sensor 2

Get Sensor

Value

√

Opens access to the

specified EEPROM

area

29

30

Open Area

0xAE

0xAF

-

√

-

No

/

Reads or writes the

8-byte FIFO register

(for fast SPI to RFID

data transfer)

Access FIFO

SL900A – 24

ams Datasheet: 2014-May-06 [v1-01]

Co mmands

Supported EPC Gen2 Commands

QuerryREP - #01

The QUERRY_REP command instructs tags to decrement their

slot counter and is specified for one out of 4 sessions. If the slot

counter becomes 0 after decrementing, the tag will backscatter

its RN16.

ACK - #02

When a tag receives the ACK command in the Reply state, it will

transition to the Acknowledged state and backscatter the EPC.

The EPC can be truncated if this has been requested by the

reader in the SELECT command. The ACK command can also be

processed in the Open or Secured states, but in this case no

state transition will occur.

Query - #03

The QUERY command initiates and specifies an inventory

round. It sets the TX and RX data rates. It also defines the

number of slots used for the inventory round. When the tag

receives the QUERY command, it will calculate a random RN16

if it has a matching Sel and Target. The tag will backscatter the

RN16 value in case the slot counter is loaded with 0.

QueryAdjust - #04

The QUERY_ADJUST command increments or decrements the

Q number (number of slots) for the current inventory round.

Select - #05

The SELECT command selects a tag population that will

participate in the inventory round, based on user-defined

criteria. The tag can receive any number of successive SELECT

commands.

NAK - #06

When a tag receives the NAK command, it will transition to the

Arbitrate state, unless it is in the Kill or Ready states. The tag

will not send any reply to the NAK command.

Req_RN - #07

The REQ_RN command will instruct the tag to backscatter a new

RN16. When a tag in the Acknowledged state receives a correct

REQ_RN command, it will transition to the Open or Secured

state. When the tag is in the Open or Secured state, it will

backscatter a new RN16 and no state transition will occur.

Read - #08

The Read command instructs the tag to read and backscatter a

part or all of the Reserved, EPC, TID or User memory.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 25

Commands

Write - #09

The WRITE command allows the interrogator to write a word (16

bits) in the tags Reserved, EPC, TID or User memory. Prior to

sending the Write command, the interrogator has to send the

REQ_RN command in order to receive a new RN16 that will be

used for cover-coding the data by EXOR-ing it with the RN16.

In case the data writing has been successful, the tag will

backscatter the response within 20ms after receiving the

command.

Kill - #10

The KILL command is used to permanently disable a tag. When

the tag receives the correct multi-step Kill procedure, it will

transition to the Killed state and will not send any response

thereafter.

Lock - #11

The LOCK command instructs the tag to lock the specified block

of the EEPROM memory. The Kill and Access passwords can be

Read/Write locked, while the EPC, TID and User block can only

be Write locked. The command will only be executed in the

Secured state.

Access - #12

The ACCESS command with a correct password and correct

multi-step procedure instructs the tag to transition from the

Open to the Secured state. When the tag has successfully

received the multi-step access procedure, it will backscatter its

handle.

BlockWrite - #13

The BLOCK_WRITE command writes a single word of data (16

bits) to the specified memory address. It provides faster data

writing than the WRITE command as it does not need a new

RN16 for every word of data that has to be written. In case the

data writing has been successful, the tag will backscatter the

response within 20ms after receiving the command.

BlockErase - #14

The BLOCK_ERASE command erases a single word in the

specified memory bank. In case the erase has been successful,

the tag will backscatter the response within 20ms after

receiving the command.

SL900A – 26

ams Datasheet: 2014-May-06 [v1-01]

Co mmands

Cool-Log Custom Commands

Set Password - #15

The SET PASSWORD command sets the password for the

specified memory area. This is the System area, Application area

and Measurement area. The System area is in the Reserved

memory bank. The Application and Measurement areas are in

the User memory bank. In case the command has executed

successfully, the tag will backscatter the response within 20ms

after receiving the command.

Set Log Mode - #16

The SET LOG MODE command sets various parameters for the

logging procedure. In case the command has executed

successfully, the tag will backscatter the response within 20ms

after receiving the command.

Set Log Limits - #17

The SET LOG LIMITS command write the 4 limits that are going

to be used for logging measurement data. The limits are:

Extreme upper limit, Upper limit, Lower limit and Extreme lower

limit. In case the command has executed successfully, the tag

will backscatter the response within 20ms after receiving the

command.

Get Measurement Setup - #18

The GET MEASUREMENT SETUP command reads 4 system blocks

- Start time, Log limits, Log mode and Delay time.

Set SFE Parameters - #19

The SET SFE PARAMETERS command sets the parameters for the

External sensor front end.

Set Calibration Data - #20

The SET CALIBRATION DATA command sets the calibration

values for the internal temperature sensor.

WARNING – the factory preset calibration data can be

overwritten. It is advised to read the calibration data, change

only the required bits and write back with the SET CALIBRATION

DATA command.

End Log - #21

The END LOG command stops the logging procedure and

returns the chip to passive mode. It also stops the timer.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 27

Commands

Start Log - #22

The START LOG command starts the logging procedure and sets

the Start time in UTC format. In logging state the chips

automatically performs the measurements and data logging in

the specified time intervals. Supported is also a delayed start,

which means that the chip will start with the logging procedure

with a specified delay after it receives the START LOG command.

This command also starts the Interrupt mode of operation

where the measurements and data-logging are driven from

external events.

Get Log State - #23

The GET LOG STATE command gets the log state of following

parameters: measurement status and out of limits counter. This

gives the ability to quickly check the state of the package

without the need to read the whole temperature data log.

Get Calibration Data - #24

The GET CALIBRATION DATA command reads the calibration

data for the internal and external sensors.

Get Battery Level - #25

The GET BATTERY LEVEL command measures and reads the

voltage level of the battery.

Set Shelf Life - #26

The SET SHELF LIFE command writes the shelf life algorithm

parameters and enables the dynamic shelf life calaculation.

Initialize - #27

The INITIALIZE command sets the size of the application data

area and sets the delay time. The command clears the

measurement status and limits counter blocks.

Get Sensor Value - #28

The GET SENSOR VALUE command measures and backscatters

the value of the specified sensor – internal, external 1 or

external 2.

Open Area - #29

The OPEN AREA command opens the specified area of the

memory (System, Application, and Measurement). The

password is stored in a RAM location and compared with the

password in EEPROM. When the tag leaves the RF field, this RAM

location is cleared.

Access FIFO - #30

The ACCESS FIFO command can read or write the 8-byte FIFO.

The FIFO can also be accessed from the SPI so this command

can be used for fast data transfer between a microcontroller

connected to the SPI and an RFID reader.

SL900A – 28

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

Upon receiving a valid command, the tag always transmits a

reply. If the command can not be executed, the tag replies with

the following error message:

Custom Command Description

Reply Structure (error):

SOF

Header

Error code

Handle

CRC

EOF

Pilot tone + preamble

1 bit [1]

8 bits

16 bits

Dummy bit [1]

The error codes are defined as:

Error Code

Error Name

Error Description

Condition

For error s that are not covered by

the other specified error codes

00000000

Other error

The EBV address is outside the

physical address of the EEPROM

or outside the specified memory

bank.

The specified memory location

does not exist or the EPC length

field is not supported by the tag

00000011

Memory overrun

The specified memory location is

locked and/or permalocked and

can not be read or written.

The lock bit for the specified

memory bank or password is

set.

00000100

00001011

Memory locked

The tag has insufficient power to

perform the memory write

operation.

This error code can only be set in

fully passive mode when the

supply voltage is to low.

Insufficient power

The password is incorrect – tag is

not open.

The IDS custom password

protection is active.

10100000

10100010

Incorrect password

Battery

The battery measurement can not

measurement error be started.

The tag is fully passive and there

is no battery attached.

Custom commands that can

modify logging and calibration

parameters are not allowed

when the tag is in active state

(RTC running).

Command not

allowed

Command is not allowed in active

state.

10100011

10100110

The memory can not be accessed

This error is reported when the

EEPROM is used by the SPI or

measurement unit.

EEPROM busy error as the measurement unit or SPI is

accessing the EEPROM.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 29

C u s t o m C o m m a n d D e s c r i p t i o n

Set Password

The SET PASSWORD command writes a 32 - bit password to the

EEPROM. The password protection for the specified area is

automatically enabled if the password is any other value

except 0.

Command Structure:

SOF

Custom Command Code Password Level Password Handle

CRC

Frame-sync

0xE0

0xA0

8 bits

32 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Password Level” bits are:

Password Level Bits

b1

0

b0

0

Passw. level

Not allowed

System

0

1

Bits b7 - b2 are X

1

0

Application

Measurement

1

When the System area is open for writing, the Set password can

change the passwords for all 3 password levels. When the

System area is write-protected, the Set password command can

not change the System password, but it can change the

Application password, if the Application area is open, and the

Measurement password when the Measurement area is open.

Set Log Mode

The SET LOG MODE command sets the logging form, storage

rule, enables sensors that are used in the logging process and

sets the logging interval (in 1 second steps).

Command Structure:

SOF

Custom

Command Code

Log Mode

Handle

CRC

Frame - sync

0xE0

0xA1

24 bits

16 bits

SL900A – 30

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

In case the operation is successful, the following reply will be

sent:

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Log mode” field is composed as:

Bit

Number

23 … 21

20

19

18

17

16

1ꢀ … 1

0

Logging

form [2:0]

Storage Ext.1sensor Ext.2sensor Temp. sensor Batterycheck

Log interval

[14:0]

RFU

Function

rule

enable

Set Log Limits

The SET LOG LIMITS command writes the 4 limits that are used

in the logging process. All 4 limits are 10 bits long.

Command Structure:

SOF

Custom

Command Code

Log Limits

Handle

CRC

Frame - sync

0xE0

0xA2

40 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Log Limits” field is composed as:

39 … 30

29 ... 20

19 … 10

Upper limit

9 … 0

Extreme upper limit

Bit Number

Function

Extreme lower limit

Lower limit

Get Measurement Setup

The GET MEASUREMENT SETUP command will read the current

system setup of the chip.

Command Structure:

SOF

Custom

Command Code

Handle

CRC

Frame - sync

0xE0

0xA3

16 bits

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 31

C u s t o m C o m m a n d D e s c r i p t i o n

Successful Reply Structure:

Applic

ation

Data

Hea Start

SOF

Log

Delay

Han

dle

CRC EOF

der Time Limits Mode Interval Time

Pilot tone

+

preamble

Dum

my

bit [1]

1 bit

[0]

32

bits

40

bits

8

bits

16

bits

16

bits

16

bits

16

bits

16

bits

The “Log Limits” field is composed as:

39 … 30

29 ... 20

19 … 10

9 … 0

Bit Number

Function

Extreme lower limit

Lower limit

Upper limit

Extreme upper limit

The “Log Mode” field is composed as:

7 ... ꢀ

4

3

2

Bit Number

Function

Logging form [2:0]

Storage rule

Ext.1 sensor enable

Ext.2 sensor enable

The “Log Interval” field is composed as:

1ꢀ … 1

Log interval [14:0]

0

Bit Number

Function

RFU

The “Delay Time” field is composed as:

1ꢀ … 4

3 … 2

1

0

Bit Number

Function

Delay mode [0 – timer, 1 –

external switch]

Delay time [11:0]

RFU [1:0]

IRQ+timer enable

The “Application Data” field is composed as:

1ꢀ … 7

Number of words for application data [8:0]

6 … 3

2 … 0

Bit Number

Function

RFU [3:0]

Broken word pointer [2:0]

SL900A – 32

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

Set SFE Parameters

The SET SFE PARAMETERS command writes the Sensor Front

End parameters to the memory. Those parameters include the

range preset values for the external sensor inputs, external

sensor types and the also the sensor that will be used for limits

comparison.

Command Structure:

SOF

Custom

Command Code

SFE Parameters

Handle

CRC

Frame - sync

0xE0

0xA4

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “SFE Parameters” field is composed as:

1ꢀ … 11

10 … 6

ꢀ … 4

3

2

1 … 0

Bit Number

Function

Autorange

disable

Verify sensor

ID [1:0]

Rang [4:0]

Seti [4:0]

EXT1 [1:0]

EXT2

Set Calibration Data

The SET CALIBRATION DATA write to the calibration block in the

EEPROM memory. The calibration data is preset during

manufacturing, but can also be changed in the application if

needed. The SET CALIBRATION DATA will write only to the

EEPROM, but it will not update the calibration values in the

calibration registers. The calibration registers are automatically

updated with each START LOG command.

Command Structure:

SOF

Custom

Command Code

Calibration Data

Handle

CRC

Frame - sync

0xE0

0xAꢀ

ꢀ6 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

Note: The “Calibration data” field is composed of 7 bytes (See “Calibration Bits” on page 63.).

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 33

C u s t o m C o m m a n d D e s c r i p t i o n

End Log

The END LOG command stops the logging procedure and turns

off the real time clock. It also clears the Active flag that is store

in the “System status” field in the EEPROM.

Command Structure:

SOF

Custom

Command Code

Handle

CRC

Frame - sync

0xE0

0xA6

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

Start Log

The START LOG command starts the logging process. It

refreshes the data in the calibration registers, enables the RTC,

writes the Start time and sets the Active bit in the “System

status” field in the EEPROM.

Command Structure:

SOF

Custom

Command Code

Start Time

Handle

CRC

Frame - sync

0xE0

0xA7

32 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Start Time” field is composed as:

31 … 26

Year [ꢀ:0]

2ꢀ … 22

Month [3:0]

21 … 17

Day [4:0]

16 … 12

Hour [4:0]

11 … 6

ꢀ … 0

Bit Number

Function

Minute [ꢀ:0]

Second [ꢀ:0]

SL900A – 34

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

Get Log State

The GET LOG STATE command reads the status of the logging

process. The command can be used to quickly determine the

current state of the product, together with the Shelf life and the

Limit counter.

Command Structure:

SOF

Custom

Command Code

Handle

CRC

Frame - sync

0xE0

0xA8

16 bits

Successful Reply Structure:

Current

Shelf

Life

Hea

der

Limit

Counter

System SL-bloc

Status Han

SOF

CRC EOF

Status

k 0&1

Flags

dle

Pilot tone

+

preamble

Dum

1 bit

[0]

32

bits

32

bits

64 bits

(see Note) (see Note)

24 bits

8

bits

16

bits

16

my

bits

bit [1]

OPTIONAL - only when Shelf Life flag is set in the EEPROM.

The “Limit Counter” field is composed as:

31 … 24

23 … 16

1ꢀ … 8

Upper [7:0]

7 … 0

Bit Number

Function

Extreme lower [7:0]

Lower [7:0]

Extreme upper [7:0]

The “System Status” field is composed as:

31 … 22

21 … 16

1ꢀ … 1

0

Bit Number

Function

Measurement address

pointer [9:0]

Number of memory

replacements [ꢀ:0]

Number of

measurements [14:0]

Active

The “Status Flags” field is composed as:

7

6

ꢀ

4

3

2

Shelf life

1

0

Bit Number

Function

Active

(logging

process)

Measure

ment

area full

Shelf life

high

error

Shelf

Life

expired

Measurement

overwritten

AD

Low

error battery low error

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 35

C u s t o m C o m m a n d D e s c r i p t i o n

Get Calibration Data

The GET CALIBRATION DATA command reads the calibration

data field and the SFE parameters field.

Command Structure:

SOF

Custom

Command Code

Handle

CRC

Frame - sync

0xE0

0xA9

16 bits

Successful Reply Structure:

Calibration Data & SFE

SOF

Header

Handle

CRC

EOF

Parameters

Pilot tone +

preamble

1 bit [0]

72 bits

16 bits

Dummy bit [1]

The content of the Calibration data field and the SFE parameters

field is displayed in the Memory map in “SPI Interface” on

page 4ꢀ.

Get Battery Level

The GET BATTERY LEVel command starts the AD conversion on

the battery voltage and returns the voltage level with the

battery type (1.ꢀV or 3V).

Command Structure:

SOF

Custom

Command Code

Battery retrigger

Handle

CRC

Frame - sync

0xE0

0xAA

8 bits

16 bits

Successful Reply Structure:

A/D

Error

Battery

Type

Battery

Level

SOF

Header

Zeros

Handle CRC

EOF

Pilot tone

+

preamble

1 bit -

error [1]

1 bit - [0 =

1.ꢀV, 1 = 3V]

4 bits

[0000]

Dummy

bit [1]

1 bit [0]

10 bits

16 bits

The application can also request the battery type re-check if

the Battery retrigger field has the value “00000001”, otherwise

the Battery retrigger field needs to have the value “00000000”.

SL900A – 36

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

Set Shelf Life

The SET SHELF LIFE command programs parameters for the

dynamic shelf life algorithm.

Command Structure:

SOF

Custom Command Code

SL Block 0

SL Block 1 Handle

CRC

Frame - sync

0xE0

0xAB

32 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “SL Block 0” field is composed as:

31 … 24

23 … 16

Tmin [7:0]

1ꢀ … 8

Tstd [7:0]

7 … 0

Bit Number

Function

Tmax [7:0]

Ea [7:0]

The “SL Block 1” field is composed as:

31 … 16

1ꢀ … 6

ꢀ … 4

3

2

1 … 0

Bit Number

Function

Enable

negative

shelf life

Shelf life

algorithm

enable

Shelf life

sensor ID [1:0]

SLinit [1ꢀ:0]

Tinit [9:0]

RFU [1:0]

Initialize

The INITIALIZE command clears the System status field, the

Limit counters and sets the Delay time field and the Application

data field. The Initialize command is needed before the START

LOG command as it will clear the pointers and counters. If the

application needs to run the logging process from the previous

point on, the Initialize command ca be left out.

Command Structure:

SOF

Custom Command Code Delay Time Application time Handle CRC

16

bits

Frame - sync

0xE0

0xAC

16 bits

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 37

C u s t o m C o m m a n d D e s c r i p t i o n

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Delay Time” field is composed as:

1ꢀ … 4

3 … 2

1

0

Bit Number

Function

Delay mode [0 – timer, 1 –

external switch]

Delay time [11:0]

RFU [1:0]

IRQ+timer enable

The “Application Data” field is composed as:

1ꢀ … 7

6 … 3

2 … 0

Bit Number

Function

Number of words for application data [8:0]

RFU [3:0]

Broken word pointer [2:0]

Get Sensor Value

The GET SENSOR VALUE command starts the AD conversion on

the specified sensor and returns the value.

Command Structure:

SOF

Custom

Command Code

Sensor Type

Handle

CRC

Frame - sync

0xE0

0xAD

8 bits

16 bits

Successful Reply Structure:

SOF

Header A/D Error Range/Limit Sensor Value Handle CRC

EOF

Pilot tone +

preamble

1 bit - error

[1]

10

bits

16

bits

16

bits

Dummy

bit [1]

(1), (2)

1 bit [0]

ꢀ bits

Note(s) and/or Footnote(s):

1. RANGE - for external sensors

2. LIMIT CURRENT - for self heating compensation.

The “Sensor Type” field is composed as:

7 … 2

1 … 0

Bit Number

Sensor type:

• 00 – Temperature sensor

• 01 – External sensor 1

• 10 – External sensor 2

• 11 – Battery voltage

RFU [ꢀ:0] – all 0’s

Function

SL900A – 38

ams Datasheet: 2014-May-06 [v1-01]

Custom Comm and Description

Open Area

The OPEN AREA command opens the specified area (System,

Application, and Measurement) that is protected by a password.

Command Structure:

SOF

Custom Command Code Password Level Password Handle CRC

Frame - sync

0xE0

0xAE

8 bits

32 bits

16 bits

Successful Reply Structure:

SOF

Header

Handle

CRC

EOF

Pilot tone + preamble

1 bit [0]

16 bits

Dummy bit [1]

The “Password Level” field is composed as:

Password Level Bits

b1

0

b0

0

Passw. level

Not allowed

System

0

1

Bits b7 - b2 are X

1

0

Application

Measurement

1

Access FIFO

The ACCESS FIFO command can read and write data from the

FIFO and can also read the FIFO status register.

Command Structure:

SOF

Custom Command Code Sub-command

Payload

Handle CRC

Frame - sync

0xE0

0xAF

8 bits

0 ~ 8 bytes

16 bits

Successful Reply Structure:

SOF

Header

Payload

Handle CRC

EOF

0 ~ 8 bytes (data from FIFO or

FIFO status register)

Pilot tone + preamble

1 bit [0]

16 bits

16 bits Dummy bit [1]

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 39

C u s t o m C o m m a n d D e s c r i p t i o n

Possible Subcommand codes are defined as:

Subcommand bits

Function

Comment

7

6

5

The bits 3-0 specify the number of bytes that will

be read from FIFO

1

0

Read data from FIFO

The bits 3-0 specify the number of bytes that will

be written to FIFO

1

0

1

0

Write data to FIFO

Read status register

The FIFO status register is defined as:

Bit #

Function

7

6

ꢀ

4

3

2

1

0

FIFO busy

Data ready

No data

0 – data from SPI, 1 – data from RFID

Number of valid bytes in FIFO register (0000 – FIFO empty, 0001 – 1 byte,

1000 – 8 bytes)

Access FIFO command example:

• Frame sync + E0 AF Aꢀ 11 22 33 44 ꢀꢀ + Handle + CRC

• This example command will write ꢀ bytes to the FIFO.

SL900A – 40

ams Datasheet: 2014-May-06 [v1-01]

Logging Formats

The logging format is selected with the SET LOG MODE

command in the “Logging Mode[2:0]” field.

Logging Formats

Figure 23:

Supported Logging Formats

Logging Mode [2:0]

Logging Form

Description

Bit 2 Bit 1 Bit 0

All values are stored to the measurement area. No additional

time information is stored to the measurement area.

0

Dense

All values that are out of the specified limits are stored to the

measurement area. Limits comparison is done on the

selected sensor (“Verify sensor ID [1:0]”). The measurement

number is stored, additional to the sensor value.

All values out of

limits

0

1

0

1

RFU

Reserved for future use – this setting is not allowed

Only the crossing point of each limit boundary is stored.

Limits comparison is done on the selected sensor (“Verify

sensor ID [1:0]”). The measurement number is stored,

additional to the sensor value.

Limits crossing

1

0

1

0

1

0

RFU

Reserved for future use – this setting is not allowed

Interrupt triggered on the EXT1 external sensor input

Interrupt triggered on the EXT2 external sensor input

IRQ, EXT1

IRQ, EXT2

Interrupt triggered on the EXT1 and EXT2 external sensor

input

1

IRQ, EXT1, EXT2

Dense Logging Form

The dense logging form provides maximum usage of the

non-volatile memory space. 8 sensor values are stored into ꢀ

words of memory when only the internal temperature sensor is

used:

Figure 24:

Dense Form - Only Internal Temperature Sensor

Bits

Block #

0x00

0x01

0x02

0x03

0x04

1ꢀ

14

13

12

11

10

9

8

7

6

ꢀ

4

3

2

1

0

Temp. 1

Temp. 2

Temp. 3

Temp. 4

Temp. ꢀ

Temp. 6

Temp. 7

Temp. 8

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 41

Lo g gi n g Fo r m a t s

In case external sensors are used for logging, the chip will use

the following storage format:

Figure 25:

Dense Form with External Sensors

Bits

Block #

0x00

1ꢀ

1

14

13

12

11

10

9

8

7

6

ꢀ

4

3

2

1

0

Range ꢀ bits

External sensor 1 - 10 bits

External sensor 2 - 10 bits

Temperature meas. - 10 bits

0x01

1

0x02

Bat. meas. 6 bits

In the dense logging form, no time information is stored in the

measurement area of the EEPROM in order to maximize the

number of stored sensor values. The real time of a particular

measurement can be calculated by using the Start time and Log

interval.

Out-of-Limits Logging Form

This logging form uses the limits that are set by the user. The

limits can be set with the SET LOG LIMITS command. The storage

data format is the same for the “All values out-of-limits” form

and the “Limits crossing” form.

Figure 26:

Limits Mode with Internal Sensor Only

Bits

Block #

0x00

1ꢀ

14

13

12

11

10

9

8

7

6

ꢀ

4

3

2

1

0

Battery voltage

Temperature

0x01

Measurement #

Figure 27:

Limits Mode with External Sensors

Bits

Block #

0x00

0x01

0x02

0x03

1ꢀ

1

14

13

12

11

10

9

8

7

6

ꢀ

4

3

2

1

0

Range ꢀ bits

External sensor 1 - 10 bits

External sensor 2 - 10 bits

Temperature meas. - 10 bits

1

Bat. meas. 6 bits

Measurement #

SL900A – 42

ams Datasheet: 2014-May-06 [v1-01]

Logging Formats

Interrupt Logging Form

This logging form is used when the interrupts from external

sensors are enabled. In this case, the real time clock is stored

together with the sensor values.

Figure 28:

Interrupt Mode

Bits

Block #

0x00

0x01

0x02

0x03

0x04

1ꢀ

1

14

13

12

11

10

9

8

7

6

ꢀ

4

3

2

1

0

Range ꢀ bits

External sensor 1 - 10 bits

External sensor 2 - 10 bits

Temperature meas. - 10 bits

1

Bat. meas. 6 bits

Real time clock - Higher 16 bits

Real time clock - Lower 16 bits

Note(s) and/or Footnote(s):

1. The interrupt source can either be the external sensor 1, external sensor 2 or both external sensors. The limits are ignored in the

interrupt mode.

Storage Capacity

The storage capacity is the number of measurement points that

can be stored to the EEPROM. It is dependent on the selected

logging form.

Figure 29:

Storage Capacity:

Selected Sensors

Dense

841

Limits (both modes)

Event Triggered

Only temperature

263

17ꢀ

131

17ꢀ

131

10ꢀ

Temperature + battery

1 External

ꢀ26

Temperature + External

Temperature + External + Battery

2 External

263

Temperature + 2 external

All 4 sensors

17ꢀ

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 43

S t o r a g e R u l e

The Storage rule defines how the device handles a completely

full Measurement area. The device has 2 storage rules – normal

or rolling.

Storage Rule

Normal storage rule

In this storage rule, the logging of new data is stopped when

the memory is completely full. When this happens, the bit 6 in

the Status Flags (Measurement area full) is set to 1 and no new

data is stored to the EEPROM. However, the timer is still active

and the Number of measurements counter will still be

incremented.

Rolling storage rule

In this mode, the device will overwrite the old data with new

data once the measurement area is completely full. When this

happens, the bit 6 (Measurement area full) and bit ꢀ

(Measurement overwritten) in the Status Flags are set to 1 and

the Number of memory replacements counter is incremented.

The new measurement is stored to the beginning of the

Measurement area.

When the dense logging mode with temperature sensor is used

with the rolling storage mode and the memory is overwritten,

the new data is stored from the beginning of the Measurement

area starting with a fresh ꢀ-block 8-measurements super-block.

It does not matter if the last super-block at the end of the

memory was not completed due to the end of the memory.

When more sensors are enabled or the limits mode is used, it

can happen that the last measurement at the end of the

memory can not be written, because there is not enough space.

An example for this is if all 4 sensors are enabled in dense

logging mode. In this case, 1 measurement is 3 blocks long. If

it happens that there are only 2 blocks free in the memory, the

measurement will be written to the beginning of the

Measurement area, so the last 2 blocks are not used.

When the Number of memory replacement counter reaches its

maximum value, the logging is stopped and no new data is

written to the EEPROM. However, the timer will still be active

and the Number of measurements counter will still be

incremented.

SL900A – 44

ams Datasheet: 2014-May-06 [v1-01]

SPI I nter face

Full and unlimited EEPROM access is possible through the SPI

interface. The primary function of the SPI interface is

production calibration and UID programming, but it can also

be used in application, for the data transmission between the

interrogator and a microcontroller attached to the SPI interface.

The chip has a basic arbitration implemented that controls the

EEPROM access from the RFID interface, the automatic data

logger and the SPI interface. The RFID interface has the highest

priority, second is the automatic data logger, and last is the SPI

interface.

SPI Interface

The first 2 bits in the frame are the MODE bits, which define the

SPI operation (00 – Write memory, 01 – Read memory, 10 – Test,

11 – Direct command). The EEPROM address is an 11-bit address

that point to the physical locations in the EEPROM. The write

command can be executed on a single byte, or any number of

successive bytes on a single page (up to 16 bytes). The minimum

number of bytes in the Page write operation is 2. The Read

operation is a continuous operation, so any number of bytes

can be read with a single frame. The address is the starting

address and is automatically incremented in the chip.

The Test MODE is reserved for production testing and cannot

be used in application.

The maximum SCLK frequency is 10MHz at 3V battery supply

(dual cell). With a 1.ꢀV battery supply the maximum frequency

is 2MHz.

Figure 30:

SPI Communication Modes

Data

Byte

MODE

EEPROM Address / Command Code

A15 A14 A13 A12 A11

A10...A0

D7...D0

0

1

Physical EEPROM address DI7 … DI0

Write Mode

Page Write

Mode

Physical EEPROM address DI7 … DI0 ...16 data bytes

...Continuous

Physical EEPROM address DO7...DO0

read (n*8 bits)

0

1

0

Read Mode

Test Mode

RESERVED for PRODUCTION

Cꢀ...C0

Command

Mode

1

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 45

S P I I n t e r f a c e

Figure 31:

SPI Timings

t

sc

t_ch

t

cl

t

ds

t

dh

Figure 32:

SPI Timing for 3V Supply Voltage

Symbol

Min

1ꢀ0us

100ns

ꢀ0ns

Max

Description

t

-

SEN to first SCLK rising edge setup time

SCLK high period

sc

t

ch

t

SCLK low period

cl

t

Data setup time

ds

t

ꢀ0ns

Data hold time

dh

Figure 33:

SPI Timing for 1.5V Supply Voltage

Symbol

Min

1ꢀ0us

ꢀ00ns

ꢀ0ns

Max

Description

SEN to first SCLK rising edge setup time

SCLK high period

t

-

sc

t

ch

t

SCLK low period

cl

t

Data setup time

ds

t

ꢀ0ns

Data hold time

dh

SL900A – 46

ams Datasheet: 2014-May-06 [v1-01]

SPI I nter face

Figure 34:

SPI Write Mode

A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0

Figure 35:

SPI Read Mode

A10

A9 A8 A7 A6 A5 A4 A3 A2 A1 A0

D7 D6 D5 D4 D3 D2 D1 D0

Figure 36:

SPI Command Mode - Start Log and Stop Log, Reset command

C5 C4 C3 C2 C1 C0

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 47

S P I I n t e r f a c e

Figure 37:

SPI Command Mode – Get Temperature, Get Ext. Sensor, Get Battery, Read Fifo, Read Remaining Shelf

Life

C5 C4 C3 C2 C1 C0

D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0

Figure 38:

SPI Write FIFO Command

Figure 39:

SPI Read FIFO Status Command

SL900A – 48

ams Datasheet: 2014-May-06 [v1-01]

SPI Direc t Command s

SPI Direct Commands

Figure 40:

SPI Direct Commands

Command Code

Command

Comment

Reset command - same

effect as POR

0x00

0x01

0x02

0x03

0x04

All calibration registers are refreshed from the EEPROM

After SDATAO signal goes high send additional 16 clock

pulses for conversion data read-out

Get temperature

Get battery

After SDATAO signal goes high send additional 16 clock

pulses for conversion data read-out

After SDATAO signal goes high send additional 16 clock

pulses for conversion data read-out

Get Ext. sensor 1

Get Ext. sensor 2

After SDATAO signal goes high send additional 16 clock

pulses for conversion data read-out

Starts the timer or IRQ mode - generates the sta_log

pulse signal - the start time has to be written before with

the SPI Write mode

0x0ꢀ

0x06

Start Logging

Stop Logging

Stops the timer or IRQ mode - generates the end_log

pulse signal

0x07

0x08

0x20

0x21

Read FIFO status

Read Remaining shelf life

Read FIFO

Read the FIFO status byte (8-bit)

Reads the remaining shelf life (24-bit)

Reads up to 8 bytes from the FIFO

Writes up to 8 bytes to the FIFO

Write FIFO

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 49

S P I D i r e c t C o m m a n d s

FIFO

The SL900A device has an integrated 8-byte FIFO register that

can be used for fast data transmission between the RFID reader

and the microcontroller that is connected to the SPI port.

The FIFO status can be determined by reading the FIFO status

register:

Bit #

Function

7

6

ꢀ

4

3

2

1

0

FIFO busy

Data ready

No data

0 – data from SPI, 1 – data from RFID

Number of valid bytes in FIFO register (0000 – FIFO empty, 0001 – 1 byte, 1000

– 8 bytes)

The FIFO can be read and written from the SPI and the RFID

interface. From the RFID interface, the ACCESS FIFO command

is used to access the FIFO register and the FIFO status. From the

SPI interface, 3 commands are used – 0x07, 0x20 and 0x21. The

0x07 commands reads the FIFO status byte. Up to 8 bytes can

be read from the FIFO with the 0x20 command and up to 8 bytes

written with the 0x21 command.

SL900A – 50

ams Datasheet: 2014-May-06 [v1-01]

Alternate Pad Func tions

Some functions are multiplexed on same pads, so some

functions of the device can not be used in parallel.

Alternate Pad Functions

Manual Log Start with Button

The SL900A device supports 2 delayed start possibilities for the

logging. Delayed start means that the logging is not started

immediately when the device receives the Start Log command,

but some time after the reception of this command. The

application can set a fixed delay for the logging, or the logging

can be started manually (without a RFID reader).

Figure 41 shows the external push button connection for the

manual delayed start function. The DIN pin has an integrated

pull-down resistor, so the only required external component is

the button. When the DIN pin is connected to V , the logging

BAT

will be started.

Figure 41:

Push Button Connection

VBAT

DIN

R=

100k

In order to enable this function, the application needs to set

the “Delay mode” bit to 1. This is done with the “Initialize”

command on page 37

External Shelf Life Alarm Function

The SL900A device can generate an alarm when the Shelf Life

algorithm is used and the shelf life expires. The EXC pin is used

for this function.

This signal can be used as an interrupt on a microcontroller, or

can be directly used to drive a LED diode. The EXC driver

resistance is 400Ω.

Figure 42 shows how to connect an LED diode to the EXC pin.

This is possible only when the transponder uses a 3V battery

supply as most of the LED diodes have a threshold above 1.ꢀV.

Depending on the type of the LED diode, also an external

current-limiting resistor needs to be used.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 51

A l t e r n a t e Pa d Fu n c t i o n s

Figure 42:

LED Connection for Shelf Life Alarm

VBAT

EXC

400 Ohm

VSS

Gnd

The external alarm function is activated automatically when the

Shelf Life algorithm is used. The “sw_ext_en” bit in Calibration

data has to be 0. If the “sw_ext_en” bit is set to 1, the EXC pin

is used for external sensor supply.

SL900A – 52

ams Datasheet: 2014-May-06 [v1-01]

Ex ternal Sensor Front-End (SFE)

The SL900A device can process the internal temperature sensor,

the battery voltage and up to 2 external sensors. The result of

the A/D conversion can be logged to the EEPROM or sent

directly back to the interrogator (if the GET SENSOR VALUE

command is used). The external sensors and the integrated

temperature sensor can only be processed in serial manner. This

is done through a multiplex amplifier, as the SL900A device has

only one A/D converter integrated.

External Sensor Front-End (SFE)

Figure 43:

External Sensor Front End

ext_sw

Vbat

Pre-

drive

current

1

4

5

2

REFERENCES

IRQ

SFE CONTROLS

6

9

EXT2

V-AGC

7

EXT1

11

VREF

EXC

I-AGC

S/H

8

Programmable Current

Sources

3

ARC

TIMING, IRQ

REFERENCE

10

MEMORY

Vbat

shelf_life

SFE Interface

The external sensor interface consists of 4 pads:

• EXT1 – connection for external sensor 1 that can be a

linear-resistive sensor, a DC voltage source (sensor with

external analog processing), capacitive and resistive

sensors with AC driving,

• EXT2 – connection for external sensor 2 that can be a

linear-conductive sensor, a reverse-polarized diode, DC

voltage source with serial resistance or a DC current

source to V

,

SS

• EXC – supply voltage for the external sensors or a AC signal

source for external sensors that do not allow a DC voltage.

• V

– reference voltage (Vo2) pin used for capacitive and

REF

resistive sensors with AC excitation.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 53

E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )

The SFE can be used for measurements with resistive sensors

with linear resistance or conductance. It can be used for

capacitive sensors and optical sensors (diode). It can also be

used for connecting integrated sensors with voltage output

(high impedance input).

The SFE allows a connection of a resistor bridge sensor

arrangement, where the bridge is supplied by the EXC pad

(battery voltage) and the 2 sensing points are attached to the

EXT1 and EXT2 inputs. The 4th point of the resistive bridge has

to be attached to the V point. The AD conversion for the 2

SS

sensing points is done with 2 successive measurements. First

the EXT1 point and next the EXT2 point. The final calculation

has to be done in the application software.

Also a capacitive or resistive sensor that does not allow a DC

voltage can be attached to the SFE. In this case, the sensing

point is the EXT1 input, the AC stimulus signal is provided by

the EXC pin and the V

pad outputs an adjustable DC

REF

reference voltage.

SFE Interface

Figure 44:

Sensor Front End Setting Bits

SFE Group Bits

Function

Description

rang[4:0]

seti[4:0]

External sensor 2 range

External sensor 1 range

Resistor feedback ladder – see application note for SFE

Current source value – see application note for SFE

00 – linear resistive sensor

01 – high impedance input (voltage follower), bridge

10 – reserved

EXT1[1:0]

external sensor 1 type

11 – capacitive or resistive sensor without DC (AC signal

on EXC pin)

0 – linear conductive sensor, opto sensor, current source

sensor

EXT2

external sensor 2 type

Use preset range

1 - high impedance input (voltage follower), bridge

Autorange function is turned off

00 – first selected sensor

Range preset

Sensor used in limit check

01 – second selected sensor

Verify sensor ID[1:0] (sensor enable bits in log

mode group)

10 – third selected sensor

11 – fourth selected sensor

SL900A – 54

ams Datasheet: 2014-May-06 [v1-01]

Ex ternal Sensor Front-End (SFE)

The external sensor interface has an auxiliary output pin (EXC)

that can be used for supplying the external sensor either with

a constant voltage or with an AC voltage signal (for capacitive

sensor).

Figure 45:

EXC Output Pin Operation

EXC Pin Controls

EXT1 [1:0] sw_ext_en stand-by mode EXC Signal Output

Comment

The output drivers are

disconnected

00

11

0

X

0

1

X

HI-Z

The output drivers are

disconnected

AC signal during external Is to be used only with

sensor conversion

capacitive sensors

The output is connected to

the battery voltage for the

duration of the conversion

V

00

1

0

1

0

1

BAT

The output drivers are

disconnected

HI-Z

The output is connected to

the battery voltage for the

duration of the conversion

V

BAT

The output drivers are

disconnected

HI-Z

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 55

E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )

External Sensor 1 Interface

The external sensor 1 interface (EXT1 pin) can be used for

measurements with linear resistive sensors and capacitive

sensors with AC excitation. It can also be used to measure 1

point of a resistive bridge (with the second point connected to

the EXT2 pad).

The processing of an external capacitive sensor without DC

voltage is possible in case an external reference capacitor is

used. The external sensor in this case is excitated with an AC

signal from the EXC pin. The connection for this kind of sensors

is shown on Figure 46.

Figure 46:

External Capacitive Sensor with AC Excitation (EXT1[1:0] = 11)

EXC

SENS

VREF

REF.

CAP.

EXT1

EXT2

VSS

Cap. No_DC

sensor

SL900A

SL900A – 56

ams Datasheet: 2014-May-06 [v1-01]

Ex ternal Sensor Front-End (SFE)

The external capacitive sensor in Figure 46 is excitated with a

square wave signal around the reference voltage V . The

REF

amplitude of the AC signal is equal to the V

AC amplitude:

voltage. Input

REF

C_{REF ⋅ CAP}

(C_{REF ⋅ CAP}+ C_SENS

------------------------------------------------------

⋅

V_EXT1= V_EXC

)

The selection of the reference capacitor depends on the AD

converter input voltage range. The input AC amplitude V

at

EXT1

minimum capacitance C_SENS must be at a maximum AD level:

V_AD2 ⋅ V_vo2– V_vo1

=

max

–

The input AC amplitude V

at minimum capacitance C_SENS

EXT1

must be close to minimum AD level:

V_ADV_vo2

=

min

–

The external sensor interface can also be used for resistive

sensor with linear resistance and with resistive sensor that do

not allow any DC voltage (AC excitation). The connection

diagrams are on Figure 47 and Figure 48.

For a resistive sensor with AC excitation The following relation

is valid:

V_VREF

--------------------------------------------------------

V_VREF< V_VREF

+

⋅ R_{REF ⋅ RES}≤ V_VREF+ vo1

R_{R SENS}+ R_{REF ⋅ RES}

–

The proper ratio between sensor and reference resistor can be

chosen to fulfill the upper relation and the range of sensor’s

resistivity.

Figure 47:

External Linear Resistive Sensor (EXT1[1:0] = 00)

EXC

VREF

EXT1

EXT2

VSS

Resistive type

sensor - linear

resistance

SL900A

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 57

E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )

An additional external reference resistor has to be used for

processing external resistive sensor with AC excitating.

Figure 48:

External Resistive Sensor with AC Signal (EXT1[1:0] = 11)

EXC

R_SENS

VREF

REF.

RES.

EXT1

EXT2

VSS

Res. No_DC

sensor

SL900A

A resistive bridge has to be connected to both sensor inputs

(Figure 49). The 2 input voltages are converted one after the

other. In automatic logging, both external sensors have to be

enabled. If the resistor bridge is also used with the GET SENSOR

VALUE RFID command, this command has to be sent twice – first

for external sensor 1, second for external sensor 2.

Figure 49:

Resistor Bridge Sensor (EXT1[1:0] = 01, EXT2 = 1)

EXC

VREF

EXT1

EXT2

VSS

External bridge

sensor

SL900A

SL900A – 58

ams Datasheet: 2014-May-06 [v1-01]

Ex ternal Sensor Front-End (SFE)

External Sensor 2 Interface

The external sensor 2 interface (EXT2 pin) can be used for

measurements with linear conductive sensors, optical sensors

(diode) and to measure the second point of a resistive bridge

(with the first point connected to the EXT1 pad) (see Figure 49).

The Figure ꢀ0 shows the connection diagram for a resistive

sensor with linear conductance (like a pressure sensor).

Figure 50:

External Resistive Sensor - Linear Conductance (EXT2 = 0)

EXC

VREF

EXT1

EXT2

VSS

Resistive type

sensor - linear

conductance

SL900A

The EXT2 pad can also be used for measurements with an

optical sensor based on reverse polarized diode current

(Figure ꢀ1).

Figure 51:

External Optical Sensor (EXT2 = 0)

EXC

VREF

EXT1

EXT2

VSS

SL900A

Opto sensor

A voltage source output sensor can be connected to the EXT2

pin. This can be used for integrated sensors with an analog

output signal.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 59

E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )

Figure 52:

External Voltage Source Sensor (EXT2 = 1)

EXC

VREF

EXT1

EXT2

VSS

Sensor -voltage

source

SL900A

The EXT1 interface can also be used for external current source

output sensors (Figure ꢀ3).

Figure 53:

External Current Source Sensor (EXT2 = 0)

EXC

VREF

EXT1

EXT2

VSS

Sensor - current

source

SL900A

External Sensor Interface Settings

The external sensor interface is set up either with the SPI

interface or with RFID custom commands. The commands

required for external sensor operation are: SET LOG MODE, SET

SFE PARAMETERS, SET CALIBRATION DATA and INITIALIZE.

The SET LOG MODE command is used to setup various

parameters required for the automatic logging process. The

command is described in “Set Log Mode” on page 30. If external

sensors are used in the logging process, they have to be enabled

with this command.

The SET SFE PARAMETERS command (“Set SFE Parameters” on

page 33) is used to set up the SFE functionality. The SFE can be

used as an automatic range selection block, for sensors with a

SL900A – 60

ams Datasheet: 2014-May-06 [v1-01]

Ex ternal Sensor Front-End (SFE)

wide output range. It can also be used as a fixed gain

preamplifier for sensors with a low output range. In this case,

the user application has to preset the range and enable the

preset values. The preset range has to be selected in case the

internal limits are used with an external sensor.

The EXT1 interface gain is preset with the “seti [4:0]” field. The

EXT2 gain is preset with the “rang [4:0]” field. The preset values

are enabled with the “Autorange Preset” flag.

The external sensor type “EXT1[1:0]” and “EXT2” can be set with

the SET SFE PARAMETERS command. This command is also used

for selecting the sensor (“Verify Sensor ID”) that will be used

with the limits in out of limits logging mode.

The SET CALIBRATION DATA command is used to set up the

supply switch for external sensors (“sw_ext_en”) and to setup

the interrupt voltage level for external sensors (“irlev[1:0]”). The

external sensors can be supplied with the battery voltage from

the EXC pin only during the conversion time. This will save

power compared to a system where the sensor is supplied

directly from the battery. This is especially useful for a resistive

bridge sensor.

The INITIALIZE command is used to setup interrupt and timer

logging modes in parallel (“IRQ + timer enable” flag). This

special logging mode can be used for regular interval-based

sensor sampling combined with the interrupt capability of the

SFE.

External Sensor Interrupt

The external sensor interface can be used for sampling short

events on the EXT1 and EXT2 pins. This can be used for shock

sensors, acceleration sensors and other pulse response sensors.

It is also useful for counting events on the external sensor pins.

The sensors are pre-driven with a small current of 12ꢀnA and

are constantly observed with a very low consumption

comparator. The overall current consumption of the interrupt

block is 0.ꢀꢁA at room temperature. In case the sensor voltage

exceeds the specified threshold (“irlev[1:0]”), the SFE will

generate and IRQ request. This will wake up the whole system

and the sensor data, together with the real time information,

will be logged to the memory.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 61

E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )

The interrupt mode is selected with the SET LOG MODE

command with the “Logging Mode[2:0]” field (“Logging

Formats” on page 41). The implemented IRQ modes are:

Figure 54:

IRQ Logging Modes

Bit 2

Bit 1

Bit 0

Logging Form

Description

Interrupt triggered on the EXT1 external

sensor input

1

0

1

IRQ, EXT1

Interrupt triggered on the EXT2 external

sensor input

1

0

1

IRQ, EXT2

Interrupt triggered on the EXT1 and EXT2

external sensor input

IRQ, EXT1, EXT2

Either of the 2 external sensor pads, or both of them, can be

used for generating an interrupt. This function can also be used

for button-triggered measurements, as the user can select

which sensor will be logged during an interrupt event.

The interrupt level can be selected by the application with the

SET CALIBRATION DATA command (“irlev[1:0]”). The setting is

valid for EXT1 and EXT2.

Figure 55:

Sensor Front End Setting Bits

Irlev [1:0]

IRQ level - % of

supply voltage

EXT1 resistive – [MΩ] EXT2 resistive - [MΩ]

Bit 1

Bit 0

0

1

0

1

0

1

< 3

< 1

< 3

< 1

< 2ꢀ %

< 8 %

< 4.2

< ꢀ.2

< 4.2

< ꢀ.2

< 3ꢀ %

< 43%

The IRQ threshold varies from chip to chip for a maximum of

2ꢀ% from its nominal specified value. The ratio between levels

at different IRQ-level-CODE remains constant. The IRQ voltage

levels are supply ratiometric.

SL900A – 62

ams Datasheet: 2014-May-06 [v1-01]

Calibration Bits

The SL900A chip is factory calibrated. The calibration settings

can be modified by the application. Some values in the

calibration data field should not be modified by the application

as this could degrade the temperature performance and the

communication stability. Those values are highlighted in the

table as DO NOT MODIFY.

Calibration Bits

The individual bits in the calibration field are:

Range

Max

Calibration

Function

Min

Step

AD lower voltage reference - fine – DO NOT

MODIFY

ad1[4:0]

-10mV

+10mV

ꢀ10mV

0.62ꢀmV

AD lower voltage reference - coarse – can be

used

coars1[2:0]

160mV

ꢀ0mV

AD higher voltage reference - fine – DO NOT

MODIFY

ad2[4:0]

coars2[2:0]

gnd_switch

-10mV

260mV

0

+10mV

610mV

0.62ꢀmV

ꢀ0mV

AD higher voltage reference - coarse

Switches the lower AD voltage reference to

ground (default = 1)

LH -1.04V

HL -0.98V

LH - 1.17V

HL - 1.11V

selp12[1:0]

adf[4:0]

POR voltage level for 1.ꢀV system

Main reference voltage calibration – DO NOT

MODIFY

622mV

800Hz

648mV

116ꢀHz

0.86mV

~1Hz

(non linear)

df[7:0]

RTC oscillator calibration

Controlled battery supply for external sensor –

the battery voltage is connected to the EXC pin

sw_ext_en

selp22[1:0]

LH - 1.9ꢀ V

HL - 1.84V

LH - 2.19V

HL - 2.07V

POR voltage level for 3V system

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 63

S h e l f L i f e C a l c u l a t i o n

Range

Calibration

Function

Min

Max

Step

43% of

Voltage interrupt level for external sensor -

ratiometric

8%, 2ꢀ%,

3ꢀ%, 43%

8% of V

irlev[1:0]

ring_cal[4:0]

off_int[6:0]

reftc[3:0]

BAT

V

BAT

Main system clock oscillator calibration – DO

NOT MODIFY

1ꢀ8ꢀkHz

-32LSb

4ꢀ0mV

2ꢀ90kHz

+32LSb

472mV

31kHz

1LSb

Temperature conversion offset calibration – DO

NOT MODIFY

Bangap voltage temperature coefficient

calibration – DO NOT MODIFY

~18ppm/C

exc_res

excitate for resistive sensors without DC

RESERVED

RFU[1:0]

Note(s) and/or Footnote(s):

1. LH – POR level rising supply

2. HL – POR level falling supply

The SL900A device has an integrated shelf life algorithm that

can dynamically calculate the remaining shelf life of the

product.

Shelf Life Calculation

It is a look-up table algorithm, where the look-up table is stored

in the first 60 bytes of the User bank. The look-up table can be

programmed with the standard EPC Write command, or

through the SPI interface.

Figure 56:

Shelf Life Look-up Table

Physical Address

Bank

Bank Name

Logical Address

Content

0x064

0x06ꢀ

~

P[0] - lookup table start

0x000

P[1]

~

3

USER

~

0x09E

0x09F

P[ꢀ8]

0x01D

P[ꢀ9] - lookup table end

The Shelf life algorithm can work with either the integrated

temperature sensor or with an external sensor. The sensor that

will be used with this algorithm can be selected with the SET

SHELF LIFE command.

SL900A – 64

ams Datasheet: 2014-May-06 [v1-01]

Shelf Life Calculatio n

Shelf Life Sensor ID [1:0]

Figure 57:

Shelf Life Sensor ID

B1

0

B0

0

Sensor Type

Temperature sensor

Ext. sensor 1

0

1

0

Ext. sensor 2

1

Battery voltage

The Shelf life algorithm is enabled with the “Enable Shelf Life”

flag in the SET SHELF LIFE command. The algorithm is activated

with the START LOG command. With this command, the

calibration data is loaded from EEPROM to the calibration

registers, the initial shelf life is set and the shelf life parameters

are set up.

Figure 58:

Shelf Life Memory Block

Physical Address

Content

Block

0x030

0x031

0x032

0x033

0x034

0x03ꢀ

0x036

Tmax[7:0]

Tmin[7:0]

Tstd[7:0]

Ea[7:0]

Shelf Life block 0

SLinit[1ꢀ:8]

Slinit[7:0]

Tinit[9:2]

Tinit[1:0]

Shelf Life block 1

ShelfLife Sensor ID [1:0]

Enable Negative ShelfLife

Shelf life algorithm enable

RFU [1:0]

0x037

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 65

S h e l f L i f e C a l c u l a t i o n

The values in the Shelf life block 0 are not used in any

calculations in the chip. They are intended as reference

information purposes for the interrogator.

Figure 59:

Shelf Life Block 0

Block

Data Field

Function

Maximal temperature for the product

Minimum temperature for the product

Normal temperature

Tmax[7:0]

Tmin[7:0]

Tstd[7:0]

Ea[7:0]

Shelf Life block 0

Activation energy

The Shelf life block 1 holds the information on the initial shelf

life and the initial temperature. Both of those values are used

in the shelf life algorithm.

Figure 60:

Shelf Life Block 1

Block

Data Field

Function

SLinit[1ꢀ:0]

Tinit[9:0]

Initial shelf life

Initial temperature used in the shelf life calculation

Sensor used for shelf life calculation (temperature,

external 1 or external 2)

ShelfLife Sensor ID [1:0]

Shelf Life block 1

Enable Negative Shelf life

Shelf life algorithm enable

RFU [1:0]

Enables negative values for shelf life

Enables the shelf life algorithm

Reserved for future use

SL900A – 66

ams Datasheet: 2014-May-06 [v1-01]

Shelf Life Calculatio n

The remaining shelf life is a 24-bit word. The remaining shelf

life, shelf life block 0&1 and the status flags can be read out with

the GET LOG STATE command (“Get Log State” on page 3ꢀ).

Figure 61:

Status Flags

Bit #

Function

Active (logging process)

Measurement area full

Measurement overwritten

AD error

7

6

ꢀ

4

3

2

1

0

Low battery

Shelf life low error (SLerrlo)

Shelf life high error (SLerrhi)

Shelf life expired

When the shelf life reaches 0, the chip can generate a signal on

the EXC pin that can be used as an interrupt source

The remaining shelf life can be read from the SPI interface with

the 0x08 SPI command.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 67

S h e l f L i f e C a l c u l a t i o n

The following is a C language representation of the shelf life

algorithm, implemented in SL900A.

At startup of logging:

SLcurr (22 bits, signed) = SLinit << 6; // multiply by 64

SLerrlo = 0;

SLerrhi = 0;

At each temperature logging event:

Tdiff (10 bits, unsigned) = Tmeas (10 bits, temperature

value) – Tinit;

Tindex (8 bits, unsigned) = Tdiff >> 2; // divide by 4

if (Tdiff > 236) {SLerrhi++; Tindex = ꢀ9}

if (Tinit > Tmeas) {SLerrlo ++; Tindex = 0}

Counter (8 bits, unsigned) = 0;

While (Counter <= Tindex)

{

SLdec (8 bits, unsigned) = P[Counter];

SLcurr = SLcurr – SLdec;

Counter++;

}

if (Tindex & (Tindex < ꢀ9)) // Interpolation process

{

SLdec++; // compensate for truncation

if (Tdiff & 0b00000010) {SLcurr = SLcurr – (SLdec

>> 1)}

if (Tdiff & 0b00000001) {SLcurr = SLcurr – (SLdec

>> 2)}

}

SL900A – 68

ams Datasheet: 2014-May-06 [v1-01]

Memor y M ap O ver view

Memory Map Overview

Figure 62:

Memory Map Overview

Physical

Address

Bank

Name

Logical

Address

Loc. #

Bank

Content

Group

System Password

[31:24]

1

2

3

0x000

System Password - read

protect

System Password

[23:16]

0x001

0x002

System Password

[1ꢀ:8]

System Password -

write protect

4

ꢀ

6

7

8

0x003

0x004

0x00ꢀ

0x006

0x007

System Password [7:0]

User Password [31:24]

User Password [23:16]

User Password [1ꢀ:8]

User Password [7:0]

User Password - read

protect

User Password - write

protect

Measurement

Password [31:24]

9

0x008

0x009

0x00A

0x00B

MeasurementPassword

- read protect

Measurement

Password [23:16]

10

11

12

X

SYSTEM

Measurement

Password [1ꢀ:8]

MeasurementPassword

- write protest

Measurement

Password [7:0]

Year [ꢀ:0]

13

14

0x00C

0x00D

Month [3:2]

Month [1:0]

Day [4:0]

Hour [4]

Start time

Hour [3:0]

Minute [ꢀ:2]

Minute [1:0]

Second [ꢀ:0]

1ꢀ

16

0x00E

0x00F

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 69

M e m o r y M a p O v e r v i e w

Physical

Address

Bank

Name

Logical

Address

Loc. #

Bank

Content

Group

ad1[4:0] - reference

voltage 1 fine cal.

17

0x010

0x011

coars1[2:0] - reference

voltage 1 coarse cal.

ad2[4:0] - reference

voltage 2 fine cal.

18

coars2[2:0] - reference

voltage 2 coarse cal.

gnd_switch

selp12[1:0] - 1.ꢀV

battery POR level

19

20

0x012

0x013

adf[4:0] - 63ꢀmV

reference voltage cal.

df[7:0] - timer oscillator

cal.

sw_ext_en - switched

battery supply for ext.

sensor

selp22[1:0] - 3V battery

POR level

X

SYSTEM

Calibration

21

22

0x014

0x01ꢀ

irlev[1:0]

ring_cal[4:2] - 1.92MHz

oscillator cal.

ring_cal[1:0]

off_int[6:1] -

temperature offset

calibration

off_int[0]

reftc[3] - band gap

temperature

coefficient cal.

reftc[2:0] - band gap

temperature

23

0x016

coefficient cal.

exc_res - excitate for

resistive sensors

without DC

RFU[1:0]

SL900A – 70

ams Datasheet: 2014-May-06 [v1-01]

Memor y M ap O ver view

Physical

Loc. #

Bank

Name

Logical

Address

Bank

Content

Group

Address

rang[4:0] - ext. sensor 2

range (feedback

resistor)

24

0x017

seti[4:2] - ext. sensor 1

range (current source)

seti[1:0] - ext. sensor 1

range

SFE parameters

sext1[1:0] - external

sensor 1 type

2ꢀ

0x018

sext2 - external sensor

2 type

Auto range preset

Verify sensor ID[1:0]

Extreme lower limit

[9:2]

26

27

0x019

0x01A

Extreme lower limit

[1:0]

X

SYSTEM

Lower limit [9:4]

Lower limit [3:0]

Upper limit [9:6]

Upper limit [ꢀ:0]

28

29

0x01B

0x01C

Limits

Extreme upper limit

[9:8]

Extreme upper limit

[7:0]

30

31

32

33

34

0x01D

0x01E

0x01F

0x020

0x021

Ext. lower limits

counter [7:0]

Lower limits counter

[7:0]

Limits counter

Higher limits counter

[7:0]

Ext. higher limits

counter [7:0]

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 71

M e m o r y M a p O v e r v i e w

Physical

Address

Bank

Name

Logical

Address

Loc. #

Bank

Content

Group

Measurement address

pointer [9:2]

3ꢀ

0x022

Measurement address

pointer [1:0]

36

0x023

Number of memory

replacements [ꢀ:0]

System status

Number of

measurements [14:7]

37

38

0x024

0x02ꢀ

Number of

measurements [6:0]

Active

Logging form [2:0]

Storage rule (0 -

normal, 1 - rolling)

Ext.1 sensor enable

Ext.2 sensor enable

Temp. sensor enable

Battery check enable

Log interval [14:7]

Log interval [6:0]

RFU

39

0x026

Log mode

Log interval

Delay time

X

SYSTEM

40

41

42

0x027

0x028

0x029

Delay time [11:4]

Delay time [3:0]

Single use flag

RFU

43

0x02A

Delay mode (0 - timer

or 1 - switch)

IRQ+timer enable

SL900A – 72

ams Datasheet: 2014-May-06 [v1-01]

Memor y M ap O ver view

Physical

Loc. #

Bank

Name

Logical

Address

Bank

Content

Group

Address

Number of blocks for

user data [8:1]

44

0x02B

Number of blocks for

user data [0]

User data

4ꢀ

46

47

0x02C

0x02D

0x02E

RFU [3:0]

Broken word pointer

[2:0]

RFU[7:0]

RFU

Kill lock [1:0]

Access lock [1:0]

EPC [1:0]

Lock bits, write ONLY

with the 'Lock'

command

TID lock [1:0]

USER lock [1:0]

RFU [ꢀ:0]

48

0x02F

49

ꢀ0

ꢀ1

ꢀ2

ꢀ3

ꢀ4

ꢀꢀ

0x030

0x031

0x032

0x033

0x034

0x03ꢀ

0x036

X

SYSTEM

Tmax[7:0]

Tmin[7:0]

Shelf Life block 0

Tstd[7:0]

Ea[7:0]

SLinit[1ꢀ:8]

Slinit[7:0]

Tinit[9:2]

Tinit[1:0]

ShelfLife Sensor ID

[1:0]

Shelf Life block 1

Enable Negative

ShelfLife

ꢀ6

0x037

Shelf life algorithm

enable

Skip log [1:0]

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 73

M e m o r y M a p O v e r v i e w

Physical

Address

Bank

Name

Logical

Address

Loc. #

Bank

Content

Group

Adjust bits for the T1

timer (default value is

“0111”

T1_delay [3:0]

FIRO_enable

cl_sh_diss

T2_diss

Enable FIRO RNG

ꢀ7

0x038

Disables the clock shop

Disables the T2 timing

Reserved for future use

KILL flag

RFU

RFU[6:0]

X

SYSTEM

ꢀ8

0x039

KILL

ꢀ9

60

61

62

63

64

6ꢀ

66

67

68

0x03A

0x03B

0x03C

0x03D

0x03E

0x03F

0x040

0x041

0x042

0x043

RFU[7:0]

RFU

RFU[7:0]

Kill Password [31:24]

Kill Password [23:16]

Kill Password [1ꢀ:8]

Kill Password [7:0]

0x00

0x01

Kill Password

Access Password

[31:24]

0

RESERVED

69

70

0x044

0x04ꢀ

0x02

0x03

0x00

0x01

Access Password

[23:16]

Access Password

71

72

0x046

0x047

Access Password [1ꢀ:8]

Access Password [7:0]

RAM -

0x00

CRC-16 is stored in the

RAM portion and is

mapped to the EPC

memory block

RAM - 1

RAM - 2

CRC-16 [1ꢀ:8]

CRC-16 [7:0]

RAM -

0x01

1

EPC

73

74

0x048

0x049

PC [1ꢀ:8]

PC [7:0]

PC

SL900A – 74

ams Datasheet: 2014-May-06 [v1-01]

Memor y M ap O ver view

Physical

Loc. #

Bank

Name

Logical

Address

Bank

Content

EPC [127:120]

Group

Address

7ꢀ

76

77

78

79

80

81

82

83

84

8ꢀ

86

87

88

89

90

91

92

93

94

9ꢀ

96

97

98

99

100

0x04A

0x04B

0x04C

0x04D

0x04E

0x04F

0x0ꢀ0

0x0ꢀ1

0x0ꢀ2

0x0ꢀ3

0x0ꢀ4

0x0ꢀꢀ

0x0ꢀ6

0x0ꢀ7

0x0ꢀ8

0x0ꢀ9

0x0ꢀA

0x0ꢀB

0x0ꢀC

0x0ꢀD

0x0ꢀE

0x0ꢀF

0x060

0x061

0x062

0x063

0x02

0x03

0x04

0x0ꢀ

0x06

0x07

0x08

0x09

0x00

0x01

0x02

0x03

0x04

EPC [119:112]

EPC [111:104]

EPC [103:96]

EPC [9ꢀ:88]

EPC [87:80]

EPC [79:72]

EPC [71:64]

EPC [63:ꢀ6]

EPC [ꢀꢀ:48]

EPC [47:40]

EPC [39:32]

EPC [31:24]

EPC [23:16]

EPC [1ꢀ:8]

1

EPC

EPC [7:0]

TID [7:0] – 0xE0

TID [1ꢀ:8] – 0x36

TID [23:16]

TID [31:24]

TID [39:32]

TID [47:40]

TID [ꢀꢀ:48]

TID [63:ꢀ6]

Chip version [7:0]

RFU [7:0]

TID (same format as UID

in ISO 1ꢀ693),

READ ONLY

2

TID

Version, etc...

READ ONLY

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 75

M e m o r y M a p O v e r v i e w

Physical

Address

Bank

Name

Logical

Address

Loc. #

Bank

Content

Group

USER memory start -

UMI

101

0x064

0x000

102

~

0x06ꢀ

~

USER / MEASUREMENT

memory – 10ꢀ2 bytes

~

3

USER

~

11ꢀ1

11ꢀ2

0x47E

0x47F

0x20D

USER memory end

SL900A – 76

ams Datasheet: 2014-May-06 [v1-01]

Applicatio ns

Applications

Battery-Assisted Transponder – Temperature

Data Logger

In the battery-assisted transponder application, only 4 pads are

used – the antenna pads and the battery pads. This kind of

circuit is suitable for a temperature data logger application.

Figure 63:

Battery-Assisted Transponder – Temperature Data Logger

16

15

14

13

V_POS

V_SSA

ANT

12

11

10

9

1

2

3

4

D_OUT

Battery

1.5V or 3V

D_IN

Dipole

Antenna

SL900A

SCLK

SEN

DIGI_TEST

5

6

7

8

Passive Transponder – Passive Temperature

Sensor

In the passive transponder, 2 pads are required for the antenna

(ANT, V ). For extended read range an external capacitor

SSA

connected between the V

and V pads is recommended.

POS

SS

Figure 64:

Passive Transponder – Passive Temperature Sensor

16

15

14

13

V_POS

V_SSA

ANT

D_OUT12

1

2

3

4

D_IN11

Optional

External

Capacitor

Dipole

Antenna

SL900A

10

SCLK

DIGI_TEST

5

SEN

9

6

7

8

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 77

Applications

Battery-Assisted Transponder with External

Microcontroller

An external microcontroller can be connected to the SL900A

device using the SPI interface. The microcontroller can read and

write the EEPROM, start and stop logging, perform an AD

conversion and data can be transmitted to the RFID reader. The

microcontroller can be used to perform additional tasks to

extend the functionality of the system.

Figure 65:

Battery-Assisted Transponder with External Microcontroller

Battery

1.5V or 3V

16

15

14

13

V_POS

V_SSA

ANT

1

2

3

4

D_OUT12

D_IN

D_IN11

D_OUT

SCLK

SEN

Dipole

Antenna

μC

SL900A

10

9

SCLK

SEN

DIGI_TEST

5

6

7

8

Battery-Assisted Transponder with Pushbutton

for Manual Delayed Log Start

In the battery-assisted transponder application, ꢀ pads are used

– the antenna pads, the battery pads and DIN for push button

input. This kind of circuit is suitable for a temperature data

logger application with manual logging start.

Figure 66:

Battery-Assisted Transponder with Pushbutton for Manual Delayed Log Start

16

15

14

13

V_POS

V_SSA

ANT

D_OUT12

1

2

3

4

D_IN11

Dipole

Antenna

SL900A

Battery

1.5V or 3V

10

SCLK

DIGI_TEST

5

SEN

9

6

7

8

SL900A – 78

ams Datasheet: 2014-May-06 [v1-01]

Applicatio ns

Dense Mode Logging – First 8 Measurements

This is a short representation of the Measurement memory, the

address pointer and the measurement counter for dense

logging mode with the integrated temperature sensor. Shown

are only the first 8 measurements – all other measurements are

stored in same manner.

Temperature data is: 0x2AA, 0x3FF, 0x2AA, 0x3FF, …

Figure 67:

Dense Mode Logging – First 8 Measurements:

No Measurement:

0

1

2

3

4

ꢀ

00000000

Address pointer

0

Measurement counter

Broken Word Pointer

Measurement 1:

0

1

2

3

4

ꢀ

10101010

10000000

00000000

Address pointer

0

1

ꢀ

00000000

Measurement counter

Broken Word Pointer

Measurement 2:

0

1

2

3

4

ꢀ

10101010

10111111

00000000

Address pointer

1

2

11110000

00000000

Measurement counter

Broken Word Pointer

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 79

Applications

Measurement 3:

0

1

2

3

4

ꢀ

10101010

10111111

10101000

00000000

Address pointer

1

3

7

11111010

00000000

Measurement counter

Broken Word Pointer

Measurement 4:

0

1

2

3

4

ꢀ

10101010

10111111

10101011

00000000

Address pointer

2

4

11111010

11111111

00000000

Measurement counter

Broken Word Pointer

Measurement 5:

0

1

2

3

4

ꢀ

10101010

10111111

10101011

10101010

00000000

Address pointer

3

ꢀ

1

11111010

11111111

10000000

00000000

Measurement counter

Broken Word Pointer

Measurement 6:

0

1

2

3

4

ꢀ

10101010

10111111

10101011

10101010

11110000

00000000

Address pointer

3

6

11111010

11111111

10111111

00000000

Measurement counter

Broken Word Pointer

SL900A – 80

ams Datasheet: 2014-May-06 [v1-01]

Applicatio ns

Measurement 7:

0

1

2

3

4

ꢀ

10101010

10111111

10101011

10101010

11111010

00000000

Address pointer

4

7

3

11111010

11111111

10111111

10101000

00000000

Measurement counter

Broken Word Pointer

Measurement 8:

0

1

2

3

4

ꢀ

10101010

10111111

10101011

10101010

11111010

11111111

00000000

Address pointer

ꢀ

8

0

11111010

11111111

10111111

10101011

00000000

Measurement counter

Broken Word Pointer

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 81

P a c k a g e D r a w i n g s & M a r k i n g s

Package Drawings & Markings

Figure 68:

Package Drawings

SL900A

Symbol

Min

Nom

0.90

Max

A

A1

b

0.80

1.00

0.203 REF

0.40

0.33

0.47

D

ꢀ.00 BSC

3.2ꢀ

E

D1

E1

e

3.1ꢀ

-

3.3ꢀ

-

3.2ꢀ

0.80 BSC

0.3ꢀꢀ

L

0.2ꢀꢀ

0.4ꢀꢀ

0.10

L1

P

4ꢀ5 BSC

0.10

aaa

ccc

0.10

SL900A Package Drawings: The reflow peak soldering temperature (body temperature) is specified according

IPC/JEDEC J-STD-020C “Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount

Devices”.

Note(s) and/or Footnote(s):

1. Dimensioning and tolerances conform to ASME Y14.5M-1994.

2. All dimensions are in millimeters. Angles are in degrees.

3. Dimension b applies to metalized terminal and is measured between 0.2ꢀmm and 0.30mm from terminal tip. Dimension L1 represents

terminal full back from package edge up to 0.1mm is acceptable.

4. Co-planarity applies to the exposed heat slug as well as the terminal.

ꢀ. Radius on terminal is optional.

6. This drawing is subject to change without notice.

SL900A – 82

ams Datasheet: 2014-May-06 [v1-01]

RoHS Compliant & ams Green Statement

RoHS: The term RoHS compliant means that ams products fully

comply with current RoHS directives. Our semiconductor

products do not contain any chemicals for all 6 substance

categories, including the requirement that lead not exceed

0.1% by weight in homogeneous materials. Where designed to

be soldered at high temperatures, RoHS compliant products are

suitable for use in specified lead-free processes.

RoHS Compliant & ams Green

Statement

ams Green (RoHS compliant and no Sb/Br): ams Green

defines that in addition to RoHS compliance, our products are

free of Bromine (Br) and Antimony (Sb) based flame retardants

(Br or Sb do not exceed 0.1% by weight in homogeneous

material).

Important Information: The information provided in this

statement represents ams knowledge and belief as of the date

that it is provided. ams bases its knowledge and belief on

information provided by third parties, and makes no

representation or warranty as to the accuracy of such

information. Efforts are underway to better integrate

information from third parties. ams has taken and continues to

take reasonable steps to provide representative and accurate

information but may not have conducted destructive testing or

chemical analysis on incoming materials and chemicals. ams

and ams suppliers consider certain information to be

proprietary, and thus CAS numbers and other limited

information may not be available for release.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 83

O r d e r i n g & C o n t a c t I n f o r m a t i o n

Ordering & Contact Information

Figure 69:

Ordering Information

Operating

Temperature

Range

Ordering

Description

Code

Package

Type

Device

Marking

Shipping

Form

QFN 16

(ꢀ x ꢀ mm)

Tape & reel

(1,000/reel)

Smart active label IC with

on-chip temperature

sensor and 9k EEPROM

SL900A-AQFT

SL900A-ASWB

-40°C to 12ꢀ°C

-405C to 12ꢀ5C

SL900A

-

Tested wafers

Ordering Information: Order quantities should be a multiple of shipping form.

Buy our products or get free samples online at:

www.ams.com/ICdirect

Technical Support is available at:

www.ams.com/Technical-Support

For further information and requests, e-mail us at:

ams_sales@ams.com

For sales offices, distributors and representatives, please visit:

www.ams.com/contact

Headquarters

ams AG

Tobelbaderstrasse 30

8141 Unterpremstaetten

Austria, Europe

Tel: +43 (0) 3136 ꢀ00 0

Website: www.ams.com

SL900A – 84

ams Datasheet: 2014-May-06 [v1-01]

Copyrights & Disclaimer

Copyright ams AG, Tobelbader Strasse 30, 8141

Copyrights & Disclaimer

Unterpremstaetten, Austria-Europe. Trademarks Registered. All

rights reserved. The material herein may not be reproduced,

adapted, merged, translated, stored, or used without the prior

written consent of the copyright owner.

Devices sold by ams AG are covered by the warranty and patent

indemnification provisions appearing in its Terms of Sale. ams

AG makes no warranty, express, statutory, implied, or by

description regarding the information set forth herein. ams AG

reserves the right to change specifications and prices at any

time and without notice. Therefore, prior to designing this

product into a system, it is necessary to check with ams AG for

current information. This product is intended for use in

commercial applications. Applications requiring extended

temperature range, unusual environmental requirements, or

high reliability applications, such as military, medical

life-support or life-sustaining equipment are specifically not

recommended without additional processing by ams AG for

each application. This Product is provided by ams “AS IS” and

any express or implied warranties, including, but not limited to

the implied warranties of merchantability and fitness for a

particular purpose are disclaimed.

ams AG shall not be liable to recipient or any third party for any

damages, including but not limited to personal injury, property

damage, loss of profits, loss of use, interruption of business or

indirect, special, incidental or consequential damages, of any

kind, in connection with or arising out of the furnishing,

performance or use of the technical data herein. No obligation

or liability to recipient or any third party shall arise or flow out

of ams AG rendering of technical or other services.

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 85

D o c u m e n t S t a t u s

Document Status

Product Status

Definition

Information in this datasheet is based on product ideas in

the planning phase of development. All specifications are

design goals without any warranty and are subject to

change without notice

Product Preview

Pre-Development

Information in this datasheet is based on products in the

design, validation or qualification phase of development.

The performance and parameters shown in this document

are preliminary without any warranty and are subject to

change without notice

Preliminary Datasheet

Datasheet

Pre-Production

Production

Information in this datasheet is based on products in

ramp-up to full production or full production which

conform to specifications in accordance with the terms of

ams AG standard warranty as given in the General Terms of

Trade

Information in this datasheet is based on products which

conform to specifications in accordance with the terms of

ams AG standard warranty as given in the General Terms of

Trade, but these products have been superseded and

should not be used for new designs

Datasheet (discontinued)

Discontinued

SL900A – 86

ams Datasheet: 2014-May-06 [v1-01]

Revision I nformation

Revision Information

Changes from 1-00 (2013-Aug) to current revision 1-01 (2014-May-06)

Page

Removed “Confidential” from footer

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 87

C o n t e n t G u i d e

1

2

General Description

Key Benefits & Features

Package Options

Applications

Content Guide

Block Diagram

3

4

6

7

Pin Assignment

Bare Die Pad Layout

Absolute Maximum Ratings

Electrical Discharge Sensitivity

Operating Conditions

Electrical Characteristics

9

Short Description

10 Supply Arrangement

10 Analog Front End (AFE)

10 Processing and Digital Control

11 Serial Interface (SPI)

11 Real-Time Clock (RTC)

11 Temperature Sensor

11 External Sensors

11 Analog to Digital Converter

11 External Sensor Interrupt

12 Data Protection

12 Shelf Life

12 Memory arrangement

13 System Description

13 Initializing the Chip

13 Power Modes

13 Ready Mode

13 Active Mode

13 Logging Mode

13 Interrupt Mode

13 Stand-by Mode

14 State Diagram

1ꢀ Data Protection

16 Data Log Functions

17 Limits Counter

18 Logging Timer

18 Delay Time

18 Analog to Digital Conversion

21 Temperature Conversion

21 Battery Voltage Conversion

22 Commands

2ꢀ Supported EPC Gen2 Commands

2ꢀ QuerryREP - #01

2ꢀ ACK - #02

2ꢀ Query - #03

2ꢀ QueryAdjust - #04

2ꢀ Select - #0ꢀ

2ꢀ NAK - #06

2ꢀ Req_RN - #07

SL900A – 88

ams Datasheet: 2014-May-06 [v1-01]

Content Guide

2ꢀ Read - #08

26 Write - #09

26 Kill - #10

26 Lock - #11

26 Access - #12

26 BlockWrite - #13

26 BlockErase - #14

27 Cool-Log Custom Commands

27 Set Password - #1ꢀ

27 Set Log Mode - #16

27 Set Log Limits - #17

27 Get Measurement Setup - #18

27 Set SFE Parameters - #19

27 Set Calibration Data - #20

27 End Log - #21

28 Start Log - #22

28 Get Log State - #23

28 Get Calibration Data - #24

28 Get Battery Level - #2ꢀ

28 Set Shelf Life - #26

28 Initialize - #27

28 Get Sensor Value - #28

28 Open Area - #29

28 Access FIFO - #30

29 Custom Command Description

30 Set Password

30 Set Log Mode

31 Set Log Limits

31 Get Measurement Setup

33 Set SFE Parameters

33 Set Calibration Data

34 End Log

34 Start Log

3ꢀ Get Log State

36 Get Calibration Data

36 Get Battery Level

37 Set Shelf Life

37 Initialize

38 Get Sensor Value

39 Open Area

39 Access FIFO

41 Logging Formats

41 Dense Logging Form

42 Out-of-Limits Logging Form

43 Interrupt Logging Form

43 Storage Capacity

44 Storage Rule

44 Normal storage rule

44 Rolling storage rule

45 SPI Interface

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 89

C o n t e n t G u i d e

49 SPI Direct Commands

ꢀ0 FIFO

51 Alternate Pad Functions

ꢀ1 Manual Log Start with Button

ꢀ1 External Shelf Life Alarm Function

53 External Sensor Front-End (SFE)

ꢀ3 SFE Interface

ꢀ4 SFE Interface

ꢀ6 External Sensor 1 Interface

ꢀ9 External Sensor 2 Interface

60 External Sensor Interface Settings

61 External Sensor Interrupt

63 Calibration Bits

64 Shelf Life Calculation

6ꢀ Shelf Life Sensor ID [1:0]

69 Memory Map Overview

77 Applications

77 Battery-Assisted Transponder – Temperature

Data Logger

77 Passive Transponder – Passive Temperature Sensor

78 Battery-Assisted Transponder with

External Microcontroller

78 Battery-Assisted Transponder with Pushbutton for

Manual Delayed Log Start

79 Dense Mode Logging – First 8 Measurements

82 Package Drawings and Markings

83 RoHS Compliant & ams Green Statement

84 Ordering & Contact Information

85 Copyrights & Disclaimer

SL900A – 90

ams Datasheet: 2014-May-06 [v1-01]


型号：	SL900A-ASWB
厂家：	AMS(艾迈斯)
描述：	EPC Class 3 Sensory Tag Chip - For Automatic Data Logging PC
文件：	总90页 (文件大小：856K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SL900A-ASWB [AMSCO]

相关型号：

SL90N0

SL90N1

SL90N2

SL90N3

SL90N4

SL90N5

SL90P0

SL90P1

SL90P4

SL90P5

SL90S0

SL90S1