ZSSC3170EE1C_技术文档

Automotive Sensor Signal Conditioner

with LIN and PWM Interface

ZSSC3170

Datasheet

Brief Description

Benefits

The ZSSC3170 is a CMOS integrated circuit for highly

accurate amplification and sensor specific correction

of bridge sensor signals. Featuring a maximum analog

gain of 420, as well as extended offset compensation

capabilities, the ZSSC3170 is adjustable to nearly all

resistive bridge sensor types.



Measurement and temperature signal available via

one output pin



Compatible with nearly all resistive bridge inputs

No external trimming components required

Single-pass calibration minimizes calibration costs

End-of-line calibration using sensor output

Digital compensation of offset, sensitivity, temperature

drift, and nonlinearity is accomplished via a 16-bit

RISC microcontroller. Conditioning coefficients are

stored in an EEPROM certified for automotive appli-

cations.

Optimized for automotive environments with

special protection circuitry, excellent electro-

magnetic compatibility, and numerous diagnostic

features; AEC-Q100-qualified

Measured values are provided by one of the digital

LIN or PWM interfaces. Each interface can support

end-of-line calibration using the sensor output. Noise

sensitivity is greatly reduced because the calibration

equipment and the ZSSC3170 are mated digitally.

Available Support



Evaluation Kit

Application Notes

Calculation Tools

For quick and easy evaluation and support for

calibrating prototypes, IDT offers the ZSSC3170 SSC

Evaluation Kit, which includes evaluation hardware,

SSOP20 samples, and software.

Physical Characteristics



Supply voltage: 7 to 18 V

Current consumption in Sleep Mode: ≤ 100μA

Input span: 1.8 to 267 mV/V

Features

ADC resolution: 13 to 14 bit



Complies with LIN specifications 1.3 / 2.0 / 2.1

Configurable LIN publisher frame content

Output resolution: up to 12-bit (LIN and PWM)

Operating temperature range: -40 to 125°C

Extended operating temperature range: ≤150°C

Data conversion rate of up to 430Hz fully utilizes

the maximum LIN channel capacity of 20kbit/s

RoHS-compliant delivery form options:

SSOP20, DFN20, or die



PWM high-side and low-side switches, support for

LIN communication for end-of-line calibration

Digital compensation of offset, gain, temperature

effects up to 2^ndorder, and nonlinearity up to 3^rd

order. Compensation of temperature sensor offset,

gain, and nonlinearity up to 2^ndorder.

ZSSC3170 Basic Circuit

LIN

GND



Internal or external temperature reference

Media temperature sensing by diode or RTD

Load dump protection of the LIN pin up to ±40V

VBAT

Accuracy

±0.25% FSO @ -20 to 85°C

±0.50% FSO @ -40 to 125°C

±1.00% FSO @ -40 to 150°C



3 EEPROM words available for optional user data

1

May 30, 2016

Automotive Sensor Signal Conditioner

with LIN and PWM Interface

ZSSC3170

Datasheet

VDDA

SCL

SDA

Ext. Temp.

Diode

VBR_T

Sensor

Bridge

I²C^TM

*

Control Registers

ZSSC3170

Block Diagram

HOUT

LOUT

Temp. Sens.

Select

Gain

Factor

Offset

Shift

ADC

Mode

RAM

PWM

LIN

VTN1

VBN

MUX

PGA

ADC

CMC

LIN

VBP

Analog Front-End (AFE)



EEPROM

Protection &

Power

Management

VB

VTN2

Internal

Temp.

Sensor

VSSE

VBR_B

VSSA

Digital Block

Interfaces

ZSSC3170

* I²C™ is a trademark of NXP.

Applications

LIN Pressure Sensor with Temperature Sensor

LIN

C3

220pF

11 LIN

10

9

8

7

6

5

4

3

2

1

VSS

VSSE

VB

Sensor Bridge

With Integrated

12

13

14

15

16

17

18

19

20

LOUT

n.c.

GND

Temperature Diode

VBAT

C2

220nF

R1

10W

VBN

HOUT

VDD

SCL

VBR_B

VBP

SCL

SDA

RTD Media

Temperature

Sensor

VTN 1

SDA

VSSA

VDDA

n.c.



VBR_T

VTN2

n.c.

R2

C1

100nF

Ordering Information (See section 7 in the data sheet for additional options.)

Product Sales Code

ZSSC3170FE1B

ZSSC3170FE1C

ZSSC3170FE2

Description

Package

ZSSC3170 Die Revision F — Temperature range: -40°C to +150°C

Unsawn on Wafer, 2450 pcs.

Sawn on Wafer Frame, 2450 pcs.

ZSSC3170 SSOP20 Revision F — Temperature range: -40°C to +150°C

Add R for 13” reel, 2000 pcs. Add T for tube, 660 pcs.

ZSSC3170EE1B

ZSSC3170EE1C

ZSSC3170EE2

ZSSC3170EE3R

ZSSC3170 Die Revision E — Temperature range: -40°C to +150°C

ZSSC3170 SSOP20 Revision E — Temperature range: -40°C to +150°C

ZSSC3170 DFN20 Revision E — Temperature Range -40°C to +150°C

Unsawn on Wafer, 2450 pcs.

Sawn on Wafer Frame, 2450 pcs.

Add R for 13” reel, 2000 pcs. Add T for tube, 660 pcs.

13” Reel, 4500 pcs

ZSSC3170EA1B

ZSSC3170EA1C

ZSSC3170EA3R

ZSSC3170 Die Revision E — Temperature range: -40°C to +125°C

ZSSC3170 DFN20 Revision E — Temperature Range -40°C to +125°C

Unsawn on Wafer, 2450 pcs.

Sawn on Wafer Frame, 2450 pcs.

13” Reel, 4500 pcs

ZSSC3170KIT

ZSSC3170 Evaluation Kit and 5 SSOP20 samples

Kit

.

2

May 30, 2016

ZSSC3170 Datasheet

Contents

1

ZSSC3170 Characteristics ............................................................................................................ 5

1.1 Absolute Maximum Ratings..................................................................................................... 5

1.2 Operating Conditions............................................................................................................... 6

1.3 Electrical Parameters .............................................................................................................. 6

1.4 Interface Characteristics........................................................................................................ 11

1.5 EEPROM .............................................................................................................................. 11

2

Circuit Description ....................................................................................................................... 12

2.1 Signal Flow and Block Diagram............................................................................................. 12

2.2 Application Modes................................................................................................................. 13

2.3 Analog Front End (AFE) ........................................................................................................ 14

2.3.1 Programmable Gain Amplifier (PGA)............................................................................... 14

2.3.2 Offset Compensation....................................................................................................... 14

2.3.3 Analog-to-Digital Converter ............................................................................................. 15

2.4 Temperature Measurement................................................................................................... 17

2.5 System Control and Conditioning Calculation........................................................................ 18

2.5.1 Operating Modes............................................................................................................. 18

2.5.2 Start-Up Phase................................................................................................................ 18

2.5.3 Measurement Cycle......................................................................................................... 19

2.5.4 Conditioning Calculation.................................................................................................. 20

2.6 Signal Outputs....................................................................................................................... 20

2.6.1 PWM Outputs HOUT and LOUT...................................................................................... 20

2.6.2 LIN Output....................................................................................................................... 21

2.7 Digital Test and Calibration Interface..................................................................................... 21

2.8 Diagnostic and Failsafe Features, Watchdog, and Error Detection........................................ 21

2.9 High Voltage, Reverse Polarity, and Short Circuit Protection................................................. 21

3

4

Application Circuit Examples and External Components ............................................................. 22

3.1 Application Circuit Examples................................................................................................. 22

3.2 Dimensioning of External Components.................................................................................. 23

Pinout and Package Options....................................................................................................... 24

4.1 Die Pad Definitions and Configuration................................................................................... 24

4.2 SSOP20 Package ................................................................................................................. 25

4.3 DFN20 Package.................................................................................................................... 25

3

May 30, 2016

ZSSC3170 Datasheet

5

6

7

8

9

ESD Protection and EMC Specification....................................................................................... 26

Reliability and RoHS Conformity ................................................................................................. 26

Ordering Information ................................................................................................................... 26

Related Documents..................................................................................................................... 27

Glossary...................................................................................................................................... 27

10 Document Revision History ......................................................................................................... 29

List of Figures

Figure 2.1 Block Diagram of ZSSC3170........................................................................................... 12

Figure 2.2 Measurement Cycle ........................................................................................................ 19

Figure 3.1 Application Circuit in PWM Mode with Low-Side Switch.................................................. 22

Figure 3.2 Application Circuit in PWM Mode with High-Side Switch ................................................. 22

Figure 3.3 Application Circuit in LIN Mode........................................................................................ 23

List of Tables

Table 1.1 Absolute Maximum Ratings............................................................................................... 5

Table 1.2 Operating Conditions......................................................................................................... 6

Table 1.3 Electrical Parameters ........................................................................................................ 6

Table 1.4 Interface Characteristics.................................................................................................. 11

Table 1.5 EEPROM ........................................................................................................................ 11

Table 2.1 Configuration for Application Modes................................................................................ 13

Table 2.2 Adjustable Gain Stages, Corresponding Sensor Signal Spans, and Common Mode Ranges

........................................................................................................................................ 14

Table 2.3 Bridge Sensor Offset Shift Ranges.................................................................................. 15

Table 2.4 A/D Resolution and Conversion Time in PWM Modes..................................................... 16

Table 2.5 A/D Resolution and Conversion Time in LIN Modes........................................................ 16

Table 3.1 Dimensioning of External Components for Application Examples.................................... 23

Table 4.1 Die Pad Definitions for ZSSC3170 .................................................................................. 24

Table 4.2 Pin Definition of SSOP20 Package.................................................................................. 25

4

May 30, 2016

ZSSC3170 Datasheet

1 ZSSC3170 Characteristics

1.1 Absolute Maximum Ratings

The absolute maximum ratings are stress ratings only. The device might not function or be operable above the

recommended operating conditions given in section 1.2. Stresses exceeding the absolute maximum ratings might

also damage the device. In addition, extended exposure to stresses above the recommended operating

conditions might affect device reliability. IDT does not recommend designing to the “Absolute Maximum Ratings.”

Parameters are valid without time limit unless otherwise noted.

Table 1.1 Absolute Maximum Ratings

No.

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

External Supply Voltage —

PWM Mode

VBAT_PWM

To VSSE (external GND)

-18

18

V

1.1.1

1), 2)

Supply Voltage on VB Pin—

PWM Mode

VB_PWM

VBAT_LIN

VB_LIN

To VSSE

-0.3

-18

-0.3

-18

18

40

18

V

1.1.2

1.1.3

1.1.4

1.1.5

1), 2)

External Supply Voltage —

To VSS (external GND)

To VSS

1), 2)

LIN Mode

Supply Voltage on VB Pin—

2)

LIN Mode ¹⁾

,

Voltage at HOUT and

V_HOUT,

V_LOUT

To VSSE

2)

LOUT Pins ¹⁾

,

2)

Voltage at LIN pin ¹⁾

,

V_LIN

VDDA

VDD

To VSS

-40

-0.3

40

6.5

V

1.1.6

1.1.7

1.1.8

Analog Supply Voltage ³⁾

Digital Supply Voltage ³⁾

To VSSA

Voltage at all other Analog or

Digital Pins ³⁾

V_AIO

V_DIO

,

VDDA

+0.3

To VSSA

-0.3

V

1.1.9

Storage Temperature

T_STOR

-40

150

170

1.1.10

1.1.11

C

Extended Storage Temperature T_{STRG_EXT}

t < 10h

1)

2)

3)

Refer to the ZSSC3170 High Voltage Protection Description for detailed specifications.

Refer to section 3.1 for the application circuit.

No measurement in mass production; parameter is guaranteed by design and/or quality monitoring.

5

May 30, 2016

ZSSC3170 Datasheet

1.2 Operating Conditions

Parameters are valid for the full operating temperature range without time limit unless otherwise noted.

Table 1.2 Operating Conditions

No.

1.2.1

1.2.2

1.2.3

Parameter

Supply Voltage ¹⁾

Supply Voltage - LIN Mode ¹⁾

Symbol

VB

Conditions

Min

8.2

7

Typ

12

Max

16.5

18

Unit

V

Voltage at pin VB to VSSE

Voltage at pin VB to VSS

VB_LIN

T_AMB

12

V

Ambient Temperature

-40

125

C

Extended Ambient Temperature

(ZSSC3170EExx only)

1.2.4

T_{AMB_EXT}1000h @ +150°C

125

150

C

Ambient Temperature

EEPROM Programming

1.2.5

1.2.6

T_{AMB_EEP}See section 1.5.

R_BR

-40

2

150

25

C

Bridge Resistance ²⁾

kW

1)

2)

Refer to the ZSSC3170 High Voltage Protection Description for detailed specifications.

No measurement in mass production; parameter is guaranteed by design and / or quality monitoring.

1.3 Electrical Parameters

If not otherwise specified, all parameter limits are valid within operating conditions defined in section 1.2 and with-

out time limit. All voltages are related to VSSA, if not otherwise specified.

Note: Refer to the important notes at the end of the table (page 10).

Table 1.3 Electrical Parameters

No.

1.3.1

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Supply Current and Internal Supply Voltages

Excluding bridge supply

current; excluding PWM

current; oscillator adjusted

(typical 2 MHz)

1.3.1.1

1.3.1.2

Supply Current

I_S

7

mA

LIN Sleep Mode without

current over LIN wire; PWM

output pins not connected;

VB_LIN= 14.4V for max. value

V_LIN=VB_LIN

Supply Current

LIN Sleep Mode

I_{S_LINSLP}

40

5

100

µA

V

V_VDA= V_VDDA- V_VSSA

at R_BR≥ 2kW (see 1.2.6)

Internal Supply Voltage

(generated internally)

1.3.1.3

1.3.1.4

V_VDA

4.3

6

Supply Voltage Sensor

Bridge (internally at VDDA

and VSSA)

V_VBR= V_VBR__T- V_{VBR B}

_

V_VDA–

0.3V

V_VBR

V_VDA

at R_BR≥ 2kW (see 1.2.6)

6

May 30, 2016

ZSSC3170 Datasheet

No.

1.3.2

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Analog Front End (see section 2.3)

1.3.2.1

1.3.2.2

Input Voltage Range

V_{IN_SPAN}

Analog gain: 2.8 to 420

1

275

388

mV/V

Maximum Bridge Sensor

Offset Compensation

Depending on selected gain

(see Table 2.3)

%

V_{IN_SPAN}

OC

Bridge Input Current

Difference ¹⁾

1.3.2.3

1.3.2.4

I_{IN_DIFF}

T_AMB= -25°C to 85°C

-2

2

nA

Dependent on selected gain,

XZC off (see Table 2.2);

see 1.3.1.4 for V_VBR

Common Mode Input

Voltage Range

V_{IN_CM}

0.29

0.65

V_VBR

1.3.3

Temperature Measurement (see section 2.4)

External Temperature

Diode Channel Gain

ppm

FS/mV

1.3.3.1

A_TSED

I_TSED

FS = Full Scale

300

10

0

1300

40

External Temperature

Diode Bias Current

1.3.3.2

1.3.3.3

20

A

External Temperature

Diode Input Range ¹⁾

V_TSED

Relative to V_{VBR_T}

1.5

V

ppm

FS/

(mV/V)

External Temperature

Resistor Channel Gain

1.3.3.4

1.3.3.5

A_TSER

1200

4500

External Temperature

Resistor Input Range ¹⁾

70%

100%

V_TSER

ST_TSI

Relative to V_VDDA-V_VSSA

V

V_VDDA-V_VSSA

Internal Temperature

Diode Sensitivity

Raw values, without

conditioning calculation

Sensor Diagnostic Tasks ²⁾

ppm

FS/K

1.3.3.6

1.3.4

700

20

2700

100

Sensor Connection Loss

Resistance Threshold

1.3.4.1

RSCC_TH

CSCC

kW

Maximum: 10nF + 20%

If Sensor Short Check is

enabled, the Sensor

Connection Check High-

Capacitances Mode must

also be enabled.

Maximum Input

Capacitance for

Sensor Connection Check

1.3.4.2

12

nF

(Also see 1.3.4.3.)

Maximum Input

Maximum: 1nF + 20%

Capacitance for Sensor

Connection Check with

Sensor Short Check and

Sensor Aging Check

Enabled

For using Sensor Short

Check and Sensor Aging

Check at the same time.

1.3.4.3

1.3.4.4

CSCC_SSC/SAC

1.2

nF

Sensor Input Short

Resistance Threshold

RSSC_TH

50

1000

W

7

May 30, 2016

ZSSC3170 Datasheet

No.

1.3.5

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

A/D Conversion (see section 2.3.3)

1.3.5.1

ADC Resolution ¹⁾

DNL ¹⁾

r_ADC

14

Bit

r_ADC= 14-bit, f_OSC= 2MHz,

1.3.5.2

1.3.5.3

DNL_ADC

best fit, complete AFE;

see 1.3.5.4 for ADC_{INP_R}

0.95

LSB

.

r_ADC= 14-bit, f_OSC= 2MHz,

best fit, complete AFE;

INL

INL_ADC

8

LSB

see 1.3.5.4 for ADC_{INP_R}

.

%

V_VBR

1.3.5.4

1.3.6

ADC Input Range

ADC_{INP_R}

See 1.3.1.4 for V_VBR

.

10

4

90

PWM Output (Pins HOUT and LOUT) ²⁾

I_SOURCE= 15mA,

VB  8.8V to VSSE

Output High Level – HSS;

HOUT Pin

1.3.6.1

V_{HSS_H}

V

Output Low Level – LSS;

LOUT Pin

1.3.6.2

1.3.6.3

V_{LSS_L}

I_SINK= 12mA to VSSE

0.5V

50

Leakage Current

LOUT Pin

I_{LEAK_LOUT}

Sink; high level at LOUT

µA

1.3.6.4

1.3.6.5

1.3.6.6

1.3.6.7

Rise Time HSS ¹⁾

Slew Rate HSS ¹⁾

t_{HSS_RISE}

SR_HSS

t_{LSS_FALL}

SR_LSS

V_HOUT= 0.5V4V

V_LOUT= 4V0.5V

15

2

µs

V/µs

µs

1)

Fall Time LSS

15

1)

Slew Rate LSS

-2

V/µs

PWM Full-Scale

Resolution ¹⁾

1.3.6.8

r_{PWM_FS}

D = 1% to 99 %

11

Bit

%

Adjustable with 8-bit

resolution

1.3.6.9

Duty Cycle ¹⁾

D

1

99

LIN Interface – Main Parameters ³⁾

(All voltages related to VSS; R_{VBAT_LIN}Power Supply Line Resistance = 500Ω)

1.3.7

Output Low Level

Transmitter

1.3.7.1

1.3.7.2

V_{LIN_L}

V_{LIN_H}

0.6

0.9

1.2

2.0

1

V

Output High Level

Transmitter

Driver off

VB

1.3.7.3

1.3.7.4

Output Current

I_{LIN_L}

Sink; driver on

40

20

90

30

200

47

mA

Pull-Up Resistance

R_{LIN_PU}

In series with diode to VB

kW

-40°C ≤ T_AMB≤ 125°C;

V_LIN VB; 7V  VB  18V;

7V  V_LIN 18V; driver off

3

20

50

µA

Input Current LIN

Recessive,

Overvoltage at LIN

1.3.7.5

I_LINPASrec

125°C ≤ T_AMB≤ 150°C;

V_LIN VB; 7V  VB  18V;

7V  V_LIN 18V; driver off

8

May 30, 2016

ZSSC3170 Datasheet

No.

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Input Current LIN

Dominant

V_LIN= 0V; VB = 12V;

driver off

1.3.7.6

I_LINPASdom

-1

mA

Input Current LIN

Recessive,

No GND for Bus

0V  V_LIN 18V;

1.3.7.7

I_{LIN_NOGND}

-1

1

mA

µA

V_GND= V_VB; VB = 12V

-40°C ≤ T_AMB≤ 125°C;

V_GND= V_SUP= 0V;

0V  V_LIN 18V

3

20

50

Input Current LIN

No GND for Bus

1.3.7.8

1.3.7.9

I_{LIN_LOSTVB}

125°C ≤ T_AMB≤ 150°C;

V_GND= V_SUP= 0V;

0V  V_LIN 18V

3

µA

Rising and falling edges,

transmit and receive

Slew Rate ³⁾

SR_LIN

0.5

1.3

3

V/µs

1.3.7.10

1.3.7.11

1.3.7.12

Input Low Level Receiver

Input High Level Receiver

Input Hysteresis Receiver

V_RECL

V_RECH

0.4

VB

0.6

V_RECHYS

V_RECHYS= V_RECH- V_RECL

0.08

0.12

Input Center Point

Receiver

1.3.7.13

V_{BUS_CNT}

V_{BUS_CNT}= (V_RECL+ V_RECH)/2

0.475

0.5

0.525

VB

TH_Rec(max)= 0.744 * VB;

TH_Dom(max)= 0.581 * VB;

VB = 7.0 to 18V; t_Bit= 50µs;

D1 = t_{BUS_rec(min)}/(2 * t_Bit)

1.3.7.14

Duty Cycle 1

Duty Cycle 2

Duty Cycle 3

D1

0.396

-

(See ZSSC3170 LIN

Interface Description

for details.)

TH_Rec(min)= 0.422 * VB;

TH_Dom(min)= 0.284 * VB;

VB = 7.6 to 18V; t_Bit= 50µs;

D1 = t_{BUS_rec(max)}/(2 * t_Bit)

1.3.7.15

1.3.7.16

D2

D3

0.581

-

(See ZSSC3170 LIN

Interface Description

for details.)

TH_Rec(max)= 0.778 * VB;

TH_Dom(max)= 0.616 * VB;

VB = 7.0 to 18V; t_Bit= 96µs;

D3 = t_{BUS_rec(min)}/(2 * t_Bit)

0.417

(See ZSSC3170 LIN

Interface Description

for details.)

9

May 30, 2016

ZSSC3170 Datasheet

No.

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

TH_Rec(min)= 0.389 * VB;

TH_Dom(min)= 0.251 * VB;

VB = 7.6 to 18V; t_Bit= 96µs;

D4 = t_{BUS_rec(max)}/(2 * t_Bit)

1.3.7.17

Duty Cycle 4

D4

0.590

-

(See ZSSC3170 LIN

Interface Description

for details.)

1.3.8

System Response

Until first valid output;

f_OSC= 2MHz

1.3.8.1

Start-Up Time ¹⁾

t_START

30

ms

Response Time

LIN_Mode;

f_OSC= 2.2MHz; 14-bit

resolution; LIN Mode;

100% final value

t_{RESP_}

LIN_2_14_5

1.3.8.2

3.6

Typical LIN

Configuration ⁴⁾

(see Table 2.5)

f_OSC= 1.8MHz; 14-bit

resolution; PWM Mode;

100% final value

Response Time PWM

Mode; Typical PWM

Configuration ⁵⁾

t_{RESP_}

PWM_2_14_2

1.3.8.3

1.3.8.4

20

ms

(see Table 2.4)

Overall Error AFE ^{6), 7)}

F_{AFE_85}

F_{AFE_125}

F_{AFE_150}

T_AMB: -20°C to 85°C

T_AMB: -40°C to 125°C

T_AMB: -40°C to 150°C

0.25

0.5

%FS

(f_OSC= 2MHz, XZC off;

no sensor related errors;

relative to digital value)

1.0

1)

2)

No measurement in mass production; parameter is guaranteed by design and/or quality observation.

In PWM Mode with Low-Side Switch (LSS) and PWM Mode with High-Side Switch (HSS), the sensor connection check (SCC) and the sensor short

check (SSC) diagnostics are available only for ZSSC3170 silicon revision “F” and any subsequent revisions

3)

4)

5)

6)

7)

For complete specification, see the ZSSC3170 LIN Interface Description.

2-step A/D conversion (ADCORD=1), 14-bit resolution (ADCRES=1), resolution 2nd conversion step 5-bit (ADCMODE=11)

2-step A/D conversion (ADCORD=1), 14-bit resolution (ADCRES=1), resolution 2nd conversion step 2-bit (ADCMODE=00)

Deviation from ideal line including INL, gain, offset, and temperature errors.

With XZC active: additional total error of max. 25ppm/K at XZC = 31. Error decreases linearly at XZC < 31.

10

May 30, 2016

ZSSC3170 Datasheet

1.4 Interface Characteristics

Table 1.4 Interface Characteristics

No.

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

I²C™ Interface

1.4.1

1)

V_{I2C_IN_H}

V_{I2C_IN_L}

Input High Level

0.8

VDDA

1.4.1.1

1.4.1.2

1.4.1.3

Input Low Level ¹⁾

Output Low Level ¹⁾

0.2

V_{I2C_OUT_L}

Open drain output current:

< 2mA

0.15

VDDA

SDA Load Capacity ¹⁾

400

100

pF

kHz

kW

C_SDA

f_SCL

1.4.1.4

1.4.1.5

SCL Clock Frequency ¹⁾

Internal Pull-Up Resistor ¹⁾

R_I2C

25

1.4.1.6

1.4.2

One-Wire Interface at HOUT and LOUT (LIN Protocol)

Input Low Level ¹⁾

Input High Level ¹⁾

Start Window ¹⁾

1

V

V_{OWI_IN_L}

1.4.2.1

1.4.2.2

1.4.2.3

V_{OWI_IN_H}

4

t_{START_WIN}

At f_OSC= 2MHz

30

ms

1)

No measurement in mass production; parameter is guaranteed by design and/or quality observation.

1.5 EEPROM

Table 1.5 EEPROM

No.

Parameter

Symbol

Conditions

Min

Typ

Max

1000

100

Unit

n_{EEP_WRI_85}T_AMB< 85°C

n_{EEP_WRI_150}T_AMB< 150°C

n_{EEP_RD}

Write Cycles

Read Cycles

1.5.1

8

10⁸

1.5.2

1.5.3

*

100000h@55°C

+ 27000h@125°C

+ 3000h@150°C

Data Retention

t_{EEP_RET}

15

a

Per written word,

at f_OSC= 2MHz

Programming Time

t_{EEP_WRI}

12

ms

1.5.4

11

May 30, 2016

ZSSC3170 Datasheet

2 Circuit Description

2.1 Signal Flow and Block Diagram

The signal path of the ZSSC3170 consists of the analog front end (AFE), the digital signal processing block, and

interfaces including protection circuitry. Based on a differential structure, the bridge inputs VBP and VBN are

handled by two signal lines each with a dynamic range symmetrical to the common mode potential (analog

ground equal to VDDA/2). Therefore it is possible to amplify positive and negative input signals within the

common mode range of the signal input.

Figure 2.1 Block Diagram of ZSSC3170

VDDA

SCL

I²C^TM*

Ext. Temp.

Diode

Control Registers

SDA

VBR_T

Sensor

Bridge

HOUT

LOUT

Temp. Sens.

Select

Gain

Factor

Offset

Shift

ADC

Mode

RAM

PWM

LIN

VTN1

VBN

MUX

PGA

ADC

CMC

LIN

VBP

Analog Front-End (AFE)



EEPROM

Protection &

Power

Management

VB

VTN2

Internal

Temp.

Sensor

VSSE

VBR_B

VSSA

Digital Block

Interfaces

ZSSC3170

* I²C™ is a trademark of NXP.

The multiplexer (MUX) transmits the signals from either the bridge sensor or the selected temperature sensors to

the analog-to-digital converter (ADC) in a defined sequence. The temperature sensor can either be an external or

internal diode or an external thermistor (RTD), selected by EEPROM configuration. In LIN Mode, temperature

output is available. For this temperature measurement, the same temperature sensor can be used as for

calibration temperature, or a second temperature sensor input can be selected. The differential signal from the

bridge sensor is pre-amplified by the programmable gain amplifier (PGA). The ADC converts bridge sensor and

temperature signals into digital values.

The digital signal conditioning takes place in the calibration microcontroller (CMC) using a ROM-resident

conditioning formula and sensor-specific coefficients stored in the EEPROM during calibration. The configuration

data and the correction parameters can be programmed into the EEPROM by digital communication at the output

pins or at the I²C™ interface. Depending on the programmed output configuration, the corrected sensor signal is

output as a PWM signal (high-side switch or low-side switch) or as a digital value within a LIN frame. During the

calibration procedure, the I²C™ interface can provide measurement values as well.

12

May 30, 2016

ZSSC3170 Datasheet

2.2 Application Modes

For each application, a configuration set must be established (generally prior to calibration) by programming the

on-chip EEPROM for the following modes:

Table 2.1 Configuration for Application Modes

Bridge Sensor Channel

Select gain stage of the AFE with respect to the maximum sensor signal span and

the zero point of the ADC.

Input Voltage Range

Bridge Sensor Offset

Compensation (XZC)

Activate the analog sensor offset compensation if required; e.g., if the sensor offset

voltage is close to or larger than the sensor span.

Select appropriate resolution of the ADC. Settings will influence sampling rate, signal

integration time, and therefore sensitivity to noise and disturbances.

Resolution/Response Time

Temperature Measurement

Temperature Measurement for the

Correction of the Bridge Signal

Select temperature sensor to calibrate temperature related errors.

Select temperature sensor for temperature measurement.

Temperature Measurement for the

Temperature Output in LIN Mode

Output Signal

Output Mode

LIN Mode

Select PWM or LIN according to application requirements.

Select LIN compatibility to specification package LIN2.1, LIN2.0, or LIN1.3.

Select switch type: high-side switch (HSS) or low-side switch (LSS).

PWM Mode

13

May 30, 2016

ZSSC3170 Datasheet

2.3 Analog Front End (AFE)

The analog front end (AFE) consists of the signal multiplexer (MUX), the programmable gain amplifier (PGA) and

the analog-to-digital converter (ADC).

2.3.1

Programmable Gain Amplifier (PGA)

Table 2.2 shows the adjustable gains, corresponding sensor signal spans, and common mode range limits. See

section 2.3.2 for details for XZC.

Table 2.2 Adjustable Gain Stages, Corresponding Sensor Signal Spans, and Common Mode Ranges

Overall

Gain

Maximum Input

Voltage Range

V_{IN_SPAN}[mV/V] ¹⁾

Gain

Input Common Mode Range

V_{IN_CM}[%VDDA] ²⁾

Amp1

Amp2

Amp3

a_IN

XZC off

XZC on

420

280

210

140

105

70

1.8

2.7

30

15

7.5

3.75

1

7

4.66

7

2

29 to 65

32 to 57

45 to 55

Not applicable

3.6

5.4

4.66

7

7.1

10.7

14.3

21.4

28.5

53.75

80

4.66

7

52.5

35

4.66

3.5

7

26.3

14

9.3

7

1

4.66

3.5

1.4

107

267

1

2.8

1

1)

2)

Recommended internal signal range: maximum 80% supply voltage. Range is defined by 80% of supply voltage divided by selected gain.

At maximum input signal (with XZC: +300% offset).

2.3.2

Offset Compensation

The ZSSC3170 supports two methods of sensor offset compensation:



Digital offset correction is processed during the digital signal conditioning by the calibration microcontroller

(CMC).



Bridge sensor offset compensation (XZC) is achieved by adding a compensation voltage at the analog

signal path that removes coarse offset. XZC is needed for large offset values that would otherwise

overdrive the analog signal path, and it can be adjusted by 6 EEPROM bits. Depending on the gain

adjustment, XZC can handle offset values of up to 300% of the sensor signal range.

14

May 30, 2016

ZSSC3170 Datasheet

Table 2.3 Bridge Sensor Offset Shift Ranges

Maximum Input

Overall Gain

Offset Shift

per Step

Approximate

Maximum Offset Shift Maximum Offset Shift

Approximate

Voltage Range

a_IN

V_{IN_SPAN}(mV/V)

(%Full Span)

12.5

7.6

(mV/V)

(%V_{IN_SPAN}

)

420

280

210

140

105

70

1.8

2.7

7.8

388

7.1

237

3.6

12.5

7.6

15.5

14.2

31

388

5.4

237

7.1

12.5

7.6

388

10.7

14.3

21.4

28.5

53.6

80

28

237

52.5

35

12.5

7.6

62

388

57

237

26.3

14

5.2

52

161

12.5

7.6

233

207

194

78

388

10

237

7

107

267

5.2

161

2.8

0.83

26

2.3.3

Analog-to-Digital Converter

The analog-to-digital converter (ADC) is designed in full differential switched capacitor technology with a

selectable resolution of 13 or 14 bits. The ADC can operate in first or second order configuration. The conversion

is largely insensitive to short-term and long-term instabilities of the clock frequency.

 MSB segment conversion: In this first step of the A/D conversion, the measurement value is integrated

over the complete conversion time ensuring a high degree of noise suppression. To extend the integration

phase to the maximum, this fraction of the complete conversion time is selected to be as long as possible

corresponding to the time available.

 LSB segment conversion: To achieve a higher resolution, the residual value of the first step is converted

in a subsequent step by a second converter. In first-order configuration, the second step is skipped (single-

step conversion).

15

May 30, 2016

ZSSC3170 Datasheet

Table 2.4 A/D Resolution and Conversion Time in PWM Modes

Mode

A/D Resolution

Total

A/D Resolution

MSB Segment

Conversion

A/D Resolution

LSB Segment

Conversion

A/D Conversion

Mode

ADC MODE ¹⁾

PWM Cycle Time

(f_OSC= 1.8MHz)

(bit)

(ms)

(bit)

12

11

10

9

(bit)

14

13

14

13

2

00

01

10

11

00

01

10

11

n/a

19.9

10.8

6.3

3

4

PWM /

ADC

5

4.0

2 step¹⁾

11

10

9

2

10.8

6.3

3

4

4.0

8

5

2.8

PWM /

ADC

1 step

14

13

n/a

37.5

19.3

1)

See the ZSSC3170 Functional Description for details.

Table 2.5 A/D Resolution and Conversion Time in LIN Modes

Mode

A/D Resolution

Total

A/D Resolution

MSB Segment

Conversion

A/D Resolution

LSB Segment

Conversion

A/D Conversion

Mode

ADC MODE ¹⁾

Response Time ²⁾

in LIN Mode

(f_OSC= 2.2MHz)

(bit)

12

11

10

9

(bit)

(ms)

16.3

8.9

14

13

14

13

2

00

01

10

11

00

01

10

11

n/a

3

4

5.2

LIN /

ADC

2 step

5

3.3

11

10

9

2

8.9

3

5.2

4

3.3

8

5

2.4

LIN /

ADC

1 step

14

13

n/a

61.5

31.7

1)

2)

See the ZSSC3170 Functional Description for details.

Total response time.

16

May 30, 2016

ZSSC3170 Datasheet

Equation (1) describes the conversion result:













V_{ADC _IN}

r

(1)

Z_ADC 2 

V_{ADC _REF} RS_ADC

Where

Z_ADC

A/D conversion result

A/D resolution in bits

r

V_{ADC_IN}Differential input voltage of ADC

V_{ADC_REF}Differential reference voltage of ADC

RS_ADC

ADC range shift adjustable by EEPROM configuration (RS_ADC= ¹/₁₆, ¹/₈, ¹/₄, ¹/₂)

By selecting different values of RS_ADC, the user can match the sensor input signal to the optimum input voltage

range of the ADC. The ADC reference voltage V_{ADC_REF}is defined as the difference between the bridge supply

potentials at pins VBR_T and VBR_B. The theoretical ADC input voltage range ADC_{INP_R}is equal to this ADC

reference voltage.

A major constraint required for achieving the specified precision as well as the stability and nonlinearity

parameters of the AFE is to use a maximum ADC input voltage range of 10% to 90% of ADC_{INP_R}within the

application. This is of special importance for ensuring the specified parameters for the entire operating

temperature range as well as all possible sensor bridge tolerances. The validity of these conditions is not checked

by the ZSSC3170’s failsafe functions and therefore must be ensured by the customer-specific configuration.

2.4 Temperature Measurement

The following temperature sensors are supported by ZSSC3170 for both temperature and calibration temperature

measurement:



Internal pn-diode

External pn-diode; anode to pin VBR_T

External resistive half-bridge with the thermistor connected in the upper branch

In PWM Mode, the conditioning calculation for the bridge sensor signal is based on values of the selected

temperature sensor.

In LIN Mode, two temperature measurements are executed using either two different sensors or one sensor for

both measurements. The temperature output value is the result of a conditioning calculation including offset

compensation, gain correction, and 2^ndorder nonlinearity compensation. The conditioning coefficients are stored

in the EEPROM.

17

May 30, 2016

ZSSC3170 Datasheet

2.5 System Control and Conditioning Calculation

The system control performs the following tasks:



Sequencing of the start-up phase

Control of measurement cycle based on EEPROM configuration data

16-bit conditioning calculation for each measurement signal based on EEPROM conditioning coefficients

and ROM-resident signal conditioning algorithm



Processing of communication requests received at the serial interfaces

Control of calibration mode

Processing of diagnostic and failsafe tasks

For a detailed description, refer to the ZSSC3170 Functional Description.

2.5.1

Operating Modes

Three main modes are implemented in the integrated state machine:



Normal Operation Mode (NOM) with continuous signal conditioning

Command Mode (CM), which provides access to all internal registers and provides the basis for

configuration and calibration of the ZSSC3170



Diagnostic Mode (DM), which indicates detected error conditions

2.5.2

Start-Up Phase

The start-up phase consists of the following time periods:



Settling of the internal voltage supply represented by the voltage VDDA-VSSA. At the end of this period,

the power-on-reset circuit (POR) switches off the reset signal.



System start, readout of EEPROM, and signature check.

Processing of the signal conditioning start routine containing bridge sensor signal and temperature

measurements, associated auto-zero measurements, and the conditioning calculation itself. Within this

period, the output pins are ready to receive special LIN frames resulting in entering the Command Mode

(CM). This start window is active for up to 30ms.

The ZSSC3170 switches into Normal Operation Mode (NOM) after the start window is passed. It proceeds with

the cyclic processing of the measurement and conditioning tasks.

18

May 30, 2016

ZSSC3170 Datasheet

2.5.3

Measurement Cycle

Depending on the EEPROM settings, the multiplexer selects the following inputs in a defined sequence:



Pre-amplified sensor bridge signal

Temperature sensor defined by EEPROM configuration for calibration temperature

Temperature sensor defined by EEPROM configuration for temperature measurement

Auto-zero signal

Diagnostic signals

The CMC controls the complete measurement cycle following a basic flow shown in Figure 2.2.

All necessary measurements for bridge sensor and temperature signal are executed once after power-on within

the start-up routine. This initial phase is followed by continuous processing of the complete measurement cycle.

The sensor connection check (SCC), sensor short check (SSC), and sensor aging check (SAC) for diagnostic

tasks (see section 2.8) are continuously executed within the regular measurement cycle even if the processing of

the diagnostic function is disabled by the EEPROM configuration.

For details, refer to the ZSSC3170 Functional Description.

Figure 2.2 Measurement Cycle

Start Routine

Bridge Sensor Signal Auto-Zero