ADT7302ARM-REEL7 [ADI]

【2∑C Accurate, MicroPower Digital Temperature Sensor in 6-Lead SOT-23; 【 2ΣC准确，微功耗数字温度传感器，采用6引脚SOT -23


型号：	ADT7302ARM-REEL7
厂家：	ADI
描述：	【2∑C Accurate, MicroPower Digital Temperature Sensor in 6-Lead SOT-23 【 2ΣC准确，微功耗数字温度传感器，采用6引脚SOT -23 传感器温度传感器
文件：	总14页 (文件大小：220K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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DT730±

FEATURES

FUNCTIONAL BLOCK DIAGRAM

13-bit temperature-to-digital converter

−40°C to +125°C operating temperature range

2°C accuracy

BAND GAP

TEMPERATURE

SENSOR

13-BIT

ANALOG/DIGITAL

CONVERTER

0.03125°C temperature resolution

Shutdown current of 1 µA

Power dissipation of 0.631 mW at V_DD= 3.3 V

SPI- and DSP-compatible serial interface

Shutdown mode

GND

TEMPERATURE

VALUE

ADT7302

SERIAL

BUS

INTERFACE

SCLK

DIN

Space-saving SOT-23 and MSOP packages

DOUT

APPLICATIONS

Medical equipment

Automotive:

Figure 1. Functional Block Diagram

Environmental controls

Oil temperature

Hydraulic systems

Cell phones

Hard disk drives

Personal computers

Electronic test equipment

Office equipment

Domestic appliances

Process control

GENERAL DESCRIPTION

PRODUCT HIGHLIGHTS

The ADT7302 is a complete temperature monitoring system

available in SOT-23 and MSOP packages. It contains a band gap

temperature sensor and a 13-bit ADC to monitor and digitize

the temperature reading to a resolution of 0.03125°C.

1. The ADT7302 has an on-chip temperature sensor that

allows an accurate measurement of the ambient tempera-

ture. The measurable temperature range is −40°C to

+125°C.

2. Supply voltage of 2.7 V to 5.5 V.

The ADT7302 has a flexible serial interface that allows easy

interfacing to most microcontrollers. The interface is compat-

ible with SPI®, QSPI™, and MICROWIRE™ protocols as well as

DSPs. The part features a standby mode that is controlled via

the serial interface.

3. Space-saving 6-lead SOT-23 and 8-lead MSOP packages.

4. Temperature accuracy of 2°C.

5. 13-bit temperature reading to 0.03125°C resolution.

The ADT7302’s wide supply voltage range, low supply current,

and SPI compatible interface make it ideal for a variety of

applications, including personal computers, office equipment,

automotive, and domestic appliances.

6. The ADT7302 features a shutdown mode that reduces the

power consumption to 4.88 µW with V_DD= 3.3 V @ 1 SPS.

Rev. PrE

Information furnished by Analog Devices is believed to be accurate and reliable.

However, no responsibility is assumed by Analog Devices for its use, nor for any

infringements of patents or other rights of third parties that may result from its use.

Specifications subject to change without notice. No license is granted by implication

or otherwise under any patent or patent rights of Analog Devices. Trademarks and

registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

Fax: 781.326.8703

www.analog.com

DT730±C

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T BLECOFC°ONTENTSC

Specifications.....................................................................................3

Temperature Value Register........................................................ 8

Serial Interface .............................................................................. 9

Microprocessor Interfacing.......................................................10

Mounting The ADT7302........................................................... 12

Supply Decoupling .....................................................................12

Outline Dimensions ....................................................................... 13

Ordering Guide............................................................................... 14

Timing Characteristics.................................................................4

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

ESD Caution..................................................................................5

Pin Configurations and Function Descriptions............................6

Typical Performance Characteristics..............................................7

Circuit Information ..........................................................................8

Converter Details..........................................................................8

REVISION HISTORY

Revision PrE: Preliminary Version

Rev. PrE | Page 2 of 14

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SPE°IFI° TIONSC

DT730±

T_A= T_MINto T_MAX, V_DD= 2.7 V to 5.5 V, unless otherwise noted. All specifications apply for –40°C to +125°C, unless otherwise stated

Table 1.

Parameter

TEMPERATURE SENSOR AND ADC

Accuracy

Min

Typ

Max

Unit

Test Conditions/Comments

V_DD= +3.3 V ( 10%) and 5 V ( 10%)

T_A= 0°C to 70°C.

TBD

°C

TBD

2.5

°C

T_A= −20°C to +85°C.

T_A= −40°C to +125°C.

Temperature Resolution

Auto Conversion Update Rate, t_R

Temperature Conversion Time

Thermal Time Constant¹

SUPPLIES

0.03125

°C

sec

Temperature measurement every 1 second

Supply Voltage

2.7

5.5

For Specified performance.

Supply Current

Normal Mode

1.6

190

1.6

280

0.2

2.2

300

2.2

400

µA

V_DD= 3.3 V. Powered up and converting

V_DD= 3.3 V. Powered up and not converting

V_DD= 5 V. Powered up and converting

V_DD= 5 V. Powered up and not converting

V_DD= 3.3 V.

Shutdown Mode

V_DD= 5 V.

Power Dissipation

Normal Mode (Average)

631

1.41

µW

V_DD= 3.3 V. Auto conversion update, t_R.

V_DD= 5 V. Auto conversion update, t_R.

Shutdown Mode (Average)²

1 SPS

4.88

7.4

42.9

423

641

µW

V_DD= 3.3 V

V_DD= 5 V

V_DD= 3.3 V

V_DD= 5 V

V_DD= 3.3 V

V_DD= 5 V

10 SPS

100 SPS

DIGITAL INPUT³

Input High Voltage, V_IH

Input Low Voltage, V_IL

Input Current, I_IN

Input Capacitance, C_IN

DIGITAL OUTPUT³

2.5

µA

0.8

V_IN= 0 V to V_DD

All digital inputs

Output High Voltage, V_OH

Output Low Voltage, V_OL

Output Capacitance, C_OUT

V_DD− 0.3 V

I_SOURCE= I_SINK= 200 µA

I_OL= 200 µA

0.4

¹Thermal Time Constant is the time it takes for a starting temperature difference to change to 36.8% of it’s starting value. For example if the ADT7302 experienced a

thermal shock from 0°C to 100°C, it would take typically 2 secs for the ADT7302 to reach 63.2°C.

²The ADT7302 is taken out of shutdown mode and a temperature conversion is immediately performed after this write operation. Once the temperature conversion is

complete, the ADT7302 is put back into shutdown mode.

³Guaranteed by design and characterization, not production tested.

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TIMING CHARACTERISTICS

Guaranteed by design and characterization, not production tested. All input signals are specified with tr = tf = 5 ns (10% to 90% of V_DD

)

and timed from a voltage level of 1.6 V. See Figure 3.

T_A= T_MINto T_MAX, V_DD= 2.7 V to 5.5 V, unless otherwise noted.

Table 2.

Parameter

t₁

Limit

Unit

ns min

Comments

to SCLK Setup Time

t₂

t₃

t₄

t₅

t₆

t₇

ns min

ns max

ns min

ns max

SCLK High Pulse Width

SCLK Low Pulse Width

Data Access Time after SCLK Falling Edge

Data Setup Time prior to SCLK Rising Edge

Data Hold Time after SCLK Rising Edge

to SCLK HoldTime

t₈

to DOUT High Impedance

¹Measured with the load circuit of Figure 2.

200µA

OUTPUT

1.6V

50pF

200µA

Figure 2. Load Circuit for Data Access Time and Bus Relinquish Time

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DT730±

BSOLUTECM XIMUMCR TINGSC

Table 3. ADT7302 Stress Ratings

Stresses above those listed under Absolute Maximum Ratings

may cause permanent damage to the device. This is a stress

rating only; functional operation of the device at these or any

other conditions above those indicated in the operational

section of this specification is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect

device reliability

Parameter

Rating

V_DDto GND

−0.3 V to +7 V

−0.3 V to V_DD+ 0.3 V

−40°C to +125°C

−65°C to +150°C

150°C

Digital Input Voltage to GND

Digital Output Voltage to GND

Operating Temperature Range

Storage Temperature Range

Junction Temperature

6-Lead SOT-23 (RJ-6)

Power Dissipation¹

1.2

1.0

0.8

W_MAX= (T_JMAX- T_A)/θ_JA

Thermal Impedance

θ_JA, Junction-to-Ambient (Still Air)

8-Lead MSOP (RM-8)

Power Dissipation¹

190.4°C/W

W_MAX= (T_JMAX- T_A)/θ_JA

Thermal Impedance³

θ_JA, Junction-to-Ambient (Still Air)

θ_JC, Junction-to-Case

IR Reflow Soldering

Peak Temperature

Time at Peak Temperature

Ramp-up Rate

SOT-23

0.6

205.9°C/W

43.74°C/W

MSOP

0.4

0.2

+220°C (−0/+5°C)

10 s to 20 s

2°C/s to 3°C/s

−6°C/sec

Ramp-down Rate

TEMPERATURE (°C)

¹Values relate to the package being used on a standard 2-layer PCB. Reference

Figure 3 for a plot of maximum power dissipation versus ambient

temperature (T_A).

Figure 3. Plot of Maximum Power Dissipation vs. Temperature

²T_A= ambient temperature

³Junction-to-case resistance is applicable to components featuring a

preferential flow direction, e.g., components mounted on a heat sink.

Junction-to-ambient resistance is more useful for air-cooled, PCB mounted

components.

ESD CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the

human body and test equipment and can discharge without detection. Although this product features

proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy

electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance

degradation or loss of functionality.

Rev. PrE | Page 5 of 14

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PINC°ONFIGUR TIONSC NDCFUN°TIONCDES°RIPTIONSC

GND

DOUT

ADT7302

TOP VIEW

(Not to Scale)

ADT7302

DOUT

GND

DIN

TOP VIEW

(Not to Scale)

SCLK

DIN

SCLK

Figure 4. SOT-23

Figure 5. MSOP

Table 4. Pin Function Description

SOT-23

Mnemonic Pin No.

Description

Analog and Digital Ground.

GND

DIN

Serial Data Input. Serial data to be loaded to the part’s control register is provided on this input. Data is clocked

into the control register on the rising edge of SCLK.

V_DD

SCLK

Positive Supply Voltage, 2.7 V to 5.5 V.

Serial Clock Input. This is the clock input for the serial port. The serial clock is used to clock data out of the

ADT7302’s temperature value register and to clock data into the ADT7302’s control register.

Chip Select Input. Logic input. The device is selected when this input is low. The SCLK input is disabled when

this pin is high.

Serial Data Output. Logic output. Data is clocked out of the temperature value register at this pin. Data is

clocked out on the falling edge of SCLK.

DOUT

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DT730±

TYPI° LCPERFORM N°EC°H R °TERISTI°SC

–000

500E-9

450E-9

400E-9

350E-9

300E-9

250E-9

200E-9

150E-9

100E-9

50E-9

–000

TBD

–000

000E+0

–000

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

ALL CAPS (Initial caps)

SupplyVoltage (V)

Figure 6. Temperature Accuracy @ 3.3 V and 5 V

Figure 9. Shutdown Current vs. Supply Voltage @ 30°C

215.0E-6

250 mv p-p ripple @ Vdd = 5 V

210.0E-6

205.0E-6

200.0E-6

195.0E-6

190.0E-6

185.0E-6

180.0E-6

175.0E-6

170.0E-6

5.5 V

3.3 V

10E+3

100E+3

1E+6

10E+6

100E+6

-5

-10

Frequency (Hz)

-45

105

155

Figure 10. Temperature Accuracy vs. Supply Ripple Frequency

Temperature (°C)

140

120

100

Figure 7. Average Operating Supply Current vs. Temperature

205E-6

200E-6

195E-6

190E-6

185E-6

180E-6

175E-6

Time (sec)

Figure 11. Response to Thermal Shock

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Supply Voltage (V)

Figure 8. Average Operating Supply Current vs. Supply Voltage @ 30°C

Rev. PrE | Page 7 of 14

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TEMPERATURE VALUE REGISTER

°IR°UITCINFORM TIONC

The temperature value register is a 14-bit read-only register that

stores the temperature reading from the ADC in 13-bit twos

complement format plus a sign bit. The MSB (DB13) is the sign

bit. The ADC can theoretically measure a 255°C temperature

span. The internal temperature sensor is guaranteed to a low

value limit of –40°C and a high limit of +125°C. The

temperature data format is shown in Table 5, which shows the

temperature measurement range of the device (–40°C to

+125°C). A typical performance curve is shown in Figure 6.

The ADT7302 is a 13-bit digital temperature sensor with a 14^th

bit that acts as a sign bit. The part houses an on-chip tempera-

ture sensor, a 13-bit A/D converter, a reference circuit, and

serial interface logic functions in SOT-23 and MSOP packages.

The A/D converter section consists of a conventional

successive-approximation converter based around a capacitor

DAC. The parts are capable of running on a 2.7 V to 5.5 V

power supply.

The on-chip temperature sensor allows an accurate measure-

ment of the ambient device temperature to be made. The

specified measurement range of the ADT7302 is −40°C to

+125°C. The structural integrity of the device starts to

deteriorate when operated at voltage and temperature

maximum specifications.

Table 5. Temperature Data Format

Temperature

−40°C

−30°C

−25°C

−10°C

−0.03125°C

0°C

+0.03125°C

+10°C

+25°C

Digital Output DB13…DB0

11, 1011 0000 0000

11, 1100 0100 0000

11, 1100 1110 0000

11, 1110 1100 0000

11, 1111 1111 1111

00, 0000 0000 0000

00, 0000 0000 0001

00, 0001 0100 0000

00, 0011 0010 0000

00, 0110 0100 0000

00, 1001 0110 0000

00, 1100 1000 0000

00, 1111 1010 0000

CONVERTER DETAILS

The conversion clock for the part is internally generated; no

external clock is required except when reading from and

writing to the serial port. In normal mode, an internal clock

oscillator runs an automatic conversion sequence. During this

automatic conversion sequence, a conversion is initiated every 1

second. At this time, the part powers up its analog circuitry and

performs a temperature conversion. This temperature

conversion typically takes 800 µs, after which time the analog

circuitry of the part automatically shuts down. The analog

circuitry powers up again when the 1 second timer times out

and the next conversion begins. The result of the most recent

temperature conversion is always available in the serial output

+50°C

+75°C

+100°C

+125°C

Temperature Conversion Formula

1. Positive Temperature = ADC Code(d)/32

2. Negative Temperature = (ADC Code*(d) ^–16384)/32

*Using all 14 bits of the data byte, includes the sign bit.

The ADT7302 can be placed in a shutdown mode via the con-

trol register, in which case the on-chip oscillator is shut down

and no further conversions are initiated until the ADT7302 is

taken out of shutdown mode. The ADT7302 can be taken out of

shutdown mode by writing all zeros into the control register.

The conversion result from the last conversion prior to shut-

down can still be read from the ADT7302 even when it is in

shutdown mode.

Negative Temperature = (ADC Code(d)* – 8192)/32

*DB13 (sign bit) is removed from the ADC code

01, 0010, 1100, 0000

75°C

00, 1001, 0110, 0000

In normal conversion mode, the internal clock oscillator is reset

after every read or write operation. This causes the device to

start a temperature conversion, the result of which is typically

available 800 µs later. Similarly, when the part is taken out of

shutdown mode, the internal clock oscillator is started and a

conversion is initiated. The conversion result is available 800 µs

later, typically. Reading from the device before a conversion is

complete causes the ADT7302 to stop converting; the part starts

again when serial communication is finished. This read

operation provides the previous result.

00, 0000, 0000, 0001

–0.03125°C

11, 1111, 1111, 1111

11, 1100, 0100, 0000

TEMPERATURE (°C)

125°C

–40°C

–30°C

11, 1011, 0000, 0000

Figure 12. Temperature to Digital Transfer Function

Rev. PrE | Page 8 of 14

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DT730±

t₁

t₇

t₂

SCLK

DOUT

t₃

t₈

t₄

DB0

DB1

LEADING ZEROS

DB13

DB12

POWER-

DOWN

DIN

Figure 13. Serial Interface Timing Diagram

SERIAL INTERFACE

Read Operation

Figure 13 shows the timing diagram for a serial read from the

data plus a sign bit are transferred during a read operation.

Read operations occur during streams of 16 clock pulses. The

first two bits out are leading zeros and the next 14 bits contain

The serial interface on the ADT7302 consists of four wires:

SCLK, DIN, and DOUT. The interface can be operated in 2-

ADT7302. The

line enables the SCLK input. Thirteen bits of

wire mode with

inter-face has read-only capability, with data being read from

and DIN tied to ground, in which case the

the data register via the DOUT line. It is advisable to utilize

which improves synchronization between the ADT7302 and the

master device. The DIN line is used to write the part into

standby mode, if required. The

device when more than one device is connected to the serial

clock and data lines.

the temperature data. If

remains low and 16 more SCLK

cycles are applied, the ADT7302 loops around and outputs the

two leading zeros plus the 14 bits of data that are in the temper-

line is used to select the

ature value register. When

returns high, the DOUT line goes

into three-state. Data is clocked out onto the DOUT line on the

falling edge of SCLK.

The part operates in a slave mode and requires an externally

applied serial clock to the SCLK input to access data from the

data register. The serial interface on the ADT7302 allows the

part to be interfaced to systems that provide a serial clock

synchronized to the serial data, such as the 80C51, 87C51,

68HC11, 68HC05 and PIC16Cxx microcontrollers as well as

DSP processors.

Write Operation

Figure 13 also shows the timing diagram for a serial write to the

ADT7302. The write operation takes place at the same time as

the read operation. Only the third bit in the data stream

provides a user-controlled function. This third bit is the power-

down bit, which, when set to a 1, puts the ADT7302 into

shutdown mode. Besides the power-down bit, all bits in the

input data stream should be zero to ensure correct operation of

the ADT7302. Data is loaded into the control register on the

16^thrising SCLK edge; the data takes effect at this time, i.e., if

A read operation from the ADT7302 accesses data from the

temperature value register while a write operation to the part

writes data to the control register.

the part is programmed to go into shutdown, it does so at this

point. If

is brought high before this 16 SCLK edge, the

control register is not loaded and the power-down status of the

part does not change. Data is clocked into the ADT7302 on the

rising edge of SCLK.

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MICROPROCESSOR INTERFACING

The ADT7302’s serial interface allows for easy interface to most

microcomputers and microprocessors. Figure 14 through

Figure 17 show some typical interface circuits. The serial

In the example shown, the ADT7302 is connected to the serial

port of the 8051. Because the serial interface of the 8051

contains only one data line, the DIN line of the ADT7302 is tied

low in the interface example given in Figure 15.

interface on the ADT7302 consists of four wires: , DIN,

DOUT and SCLK. All interface circuits shown utilize all four

interface lines. However, it is possible to operate the interface

with three wires. If the application does not require the power-

down facility offered by the ADT7302, the DIN line can be tied

permanently low. Thus, the interface can be operated from just

For applications that require the ADT7302’s power-down

feature, the serial interface should be implemented using data

port lines on the 8051. This allows a full-duplex serial interface

to be implemented. The method involves “bit-banging” a port

line to generate a serial clock while using two other port lines to

three wires: SCLK, , and DOUT.

shift data in and out with the fourth port line connecting to

Port lines 1.0 through 1.3 (with P1.1 configured as an input)

The serial data transfer to and from the ADT7302 requires a 16-

bit read operation. Many 8-bit microcontrollers have 8-bit serial

ports, and this 16-bit data transfer is handled as two 8-bit trans-

fers. Other microcontrollers and DSP processors transfer 16 bits

of data in a serial data operation.

can be used to connect to SCLK, DOUT, DIN, and

respectively, to implement this scheme.

8051*

ADT7302*

ADT7302 to MC68HC11 Interface

P3.1

P3.0

P1.2

P1.3

SCLK

DOUT

DIN

Figure 14 shows an interface between the ADT7302 and the

MC68HC11 microcontroller. The MC68HC11 is configured in

master mode with its CPOL and CPHA bits set to a Logic 1.

When the MC68HC11 is configured like this, its SCLK line

idles high between data transfers. Data is transferred to and

from the ADT7302 in two 8-bit serial data operations. The

diagram shows the full (4-wire) interface. PC1 of the

*ADDITIONAL PINS OMITTED FOR CLARITY

Figure 15. ADT7302 to 8051 Interface

MC68HC11 is configured as an output and is used to drive the

input.

ADT7302 to PIC16C6x/7x and PIC16F873 Interface

Figure 16 shows an interface circuit between the ADT7302 and

the PIC16C6x/7x microcontroller. The PIC16C6x/7x

MC68HC11*

SCLK

ADT7302*

SCLK

synchronous serial port (SSP) is configured as an SPI master

with the clock polarity bit set to a Logic 1. In this mode, the

serial clock line of the PIC16C6x/7x idles high between data

transfers. Data is transferred to and from the ADT7302 in two

8-bit serial data operations. In the example shown, port line

DOUT

DIN

MISO

MOSI

PC1

RA1 is being used to generate the

for the ADT7302.

*ADDITIONAL PINS OMITTED FOR CLARITY

Figure 14. ADT7302 to MC68HC11 Interface

PIC16C6x/7x*

SCK

ADT7302*

SCLK

ADT7302 to 8051 Interface

SDO

SDI

DOUT

DIN

An interface circuit between the ADT7302 and the microcon-

troller is shown in Figure 15. The 8051 is configured in its Mode

0 serial interface mode. The serial clock line of the 8051 (on

P3.1) idles high between data transfers. Data is transferred to

and from the ADT7302 in two 8-bit serial data operations. The

ADT7302 outputs the MSB of its data stream as the first valid

bit while the 8051 expects the LSB first. Thus, the data read into

the serial buffer needs to be rearranged before the correct data-

word from the ADT7302 is available in the accumulator.

RA1

*ADDITIONAL PINS OMITTED FOR CLARITY

Figure 16. ADT7302 to PIC16C6x/7x Interface

The following software program shows how to program an

PIC16F873 to communicate with the ADT7302. The

PIC16F873 is configured as an SPI master with the PortA.1 pin

used as . Any Microchip microcontroller can use this

program by simply exchanging the include file for the device

that’s being used.

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DT730±

#include <16F873.h>

#device adc=8

#use delay(clock=4000000)

#fuses NOWDT,XT, PUT, NOPROTECT, BROWNOUT, LVP

#BIT CKP = 0x14.4

#define CS PIN_A1

void main(){

int MSByte,LSByte;

long int ADC_Temp_Code;

float TempVal,ADC_Temp_Code_dec;

setup_spi(spi_master);

CKP = 1;

//Pic is set up as Master device.

//Idle state of clock is high.

do{

delay_ms(10);

//Allow time for conversions.

Output_low(CS);

//Pull CS low.

delay_us(10);

MSByte = SPI_Read(0);

LSByte = SPI_Read(0);

//CS to SCLK setup time.

//The first byte is clocked in.

//The second byte is clocked in.

delay_us(10);

Output_High(CS);

//SCLK to CS setup time.

//Bring CS high.

MSByte = 0x03;

LSByte = 0x20;

ADC_Temp_Code = make16(MSByte,LSByte);

ADC_Temp_Code_dec = (float)ADC_Temp_Code;

//16bit ADC code is stored ADC_Temp_Code.

//Covert to float for division.

if ((0x2000 & ADC_Temp_Code) == 0x2000)

//Check sign bit for negative value.

{

TempVal = (ADC_Temp_Code_dec - 16384)/32;

//Conversion formula if negative temperature.

}

else

{

TempVal = (ADC_Temp_Code_dec/32);

}

}while(True);

//Conversion formula if positive temperature.

//Temperature value stored in TempVal.

}

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ADT7302 to ADSP-21xx Interface

MOUNTING THE ADT7302

Figure 17 shows an interface between the ADT7302 and the

ADSP-21xx DSP processor. To ensure correct operation of the

interface, the SPORT control register should be set up as

follows:

The ADT7302 can be used for surface- or air-temperature

sensing applications. If the device is cemented to a surface with

thermally conductive adhesive, the die temperature will be

within about 0.1°C of the surface temperature, thanks to the

ADT7302’s low power consumption. Care should be taken to

insulate the back and leads of the device from the air if the

ambient air temperature is different from the surface tempera-

ture being measured.

TFSW = RFSW = 1, alternate framing

INVRFS = INVTFS = 1, active low framing signal

DTYPE = 00, right justify data

SLEN = 1111, 16-bit data-words

ISCLK = 1, internal serial clock

The ground pin provides the best thermal path to the die, so the

temperature of the die will be close to that of the printed circuit

ground track. Care should be taken to ensure that this is in

good thermal contact with the surface being measured.

TFSR = RFS = 1, frame every word

IRFS = 0, RFS configured as input

ITFS = 1, TFS configured as output

The interface requires an inverter between the SCLK line of the

ADSP-21xx and the SCLK input of the ADT7302. The ADSP-

21xx has the TFS and RFS of the SPORT tied together, with TFS

set as an output and RFS set as an input. The DSP operates in

alternate framing mode, and the SPORT control register is set

up as described previously.

As with any IC, the ADT7302 and its associated wiring and

circuits must be kept free from moisture to prevent leakage and

corrosion, particularly in cold conditions where condensation is

more likely to occur. Water-resistant varnishes and conformal

coatings can be used for protection. The small size of the

ADT7302 allows it to be mounted inside sealed metal probes,

which provide a safe environment for the device.

SUPPLY DECOUPLING

ADSP-21xx*

SCK

ADT7302*

SCLK

The ADT7302 should be decoupled with a 0.1 µF ceramic

capacitor between V_DDand GND. This is particularly important

if the ADT7302 is mounted remote from the power supply.

DOUT

DIN

RFS

TFS

*ADDITIONAL PINS OMITTED FOR CLARITY

Figure 17. ADT7302 to ADSP-21 Interface

Rev. PrE | Page 12 of 14

PueliminruyCTeAhniArlCDrarC

OUTLINECDIMENSIONSC

DT730±

2.90 BSC

2.80 BSC

1.60 BSC

PIN 1

0.95 BSC

1.90

BSC

1.30

1.15

0.90

1.45 MAX

0.22

0.08

10°

4°

0°

0.60

0.45

0.30

0.50

0.30

0.15 MAX

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MO-178AB

Figure 18. 6-Lead Small Outline Transistor Package [SOT-23]

(RJ-6)

Dimensions shown in millimeters

3.00

BSC

4.90

BSC

3.00

BSC

PIN 1

0.65 BSC

1.10 MAX

0.15

0.00

0.80

0.60

0.40

8°

0°

0.38

0.22

0.23

0.08

COPLANARITY

0.10

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MO-187AA

Figure 19. 8-Lead Mini Small Outline Package [MSOP]

(RM-8)

Dimensions shown in millimeters

Rev. PrE | Page 13 of 14

DT730±C

PueliminruyCTeAhniArlCDrar

ORDERINGCGUIDEC

Temperature

Accuracy¹

Package

Description

Samples Branding

Information

T01

Package

Option

RJ-6

RM-8

RJ-6

Model

Temperature Range

−40°C to +125°C

ADT7302ART-500RL7

ADT7302ART-REEL7

ADT7302ART-REEL

ADT7302ARM

ADT7302ARM-REEL7

ADT7302ARM-REEL

ADT7302ARTZ-500RL7²

ADT7302ARTZ-REEL7²

ADT7302ARTZ-REEL²

ADT7302ARMZ²

2°C

6-Lead SOT-23

8-Lead MSOP

6-Lead SOT-23

8-Lead MSOP

RM-8

ADT7302ARMZ-REEL7²

ADT7302ARMZ-REEL²

¹Temperature accuracy is over 0°C to 70°C temperature range.

²Z = Pb-free.

registered trademarks are the property of their respective owners.

PR04662-0-8/04(PrE)

Rev. PrE | Page 14 of 14

ADT7302ARM-REEL7 [ADI]

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