8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

The TMP175 and TMP75 devices are used to measure the PCB temperature of the location it is mounted. The

TMP175 and TMP75 feature SMBus, two-wire, and I2C interface compatibility, with the TMP175 allowing up to

27 devices on one bus and the TMP75 allowing up to eight devices on one bus. The TMP175 and TMP75 both

feature an SMBus Alert function. The TMP175 and TMP75 require no external components for operation except

for pullup resistors on SCL, SDA, and ALERT, although a 0.01-μF bypass capacitor is recommended.

The sensing device of the TMP175 and TMP75 devices is the device itself. Thermal paths run through the

package leads as well as the plastic package. The lower thermal resistance of metal causes the leads to provide

the primary thermal path.

8.2 Typical Application

SCL

ALERT

GND

2

6

1

A0

V+

3

5

0.01 µF

Two-Wire

Host Controller

TMP175,

TMP75

2.7V to 5.5V

SDA

Pullup Resistors

Supply Bypass

Capacitor

Supply Voltage

4.7 k

A1

A2

4

7

8

Figure 8-1. Typical Connections of the TMP175 and TMP75

8.2.1 Design Requirements

The TMP175 and TMP75 devices requires pullup resistors on the SCL, SDA, and ALERT pins. The

recommended value for the pullup resistor is 4.7 kΩ. In some applications the pullup resistor can be lower

or higher than 4.7 kΩ but must not exceed 3 mA of current on the SCL and SDA pins, and must not exceed 4

mA on the ALERT pin. A 0.01-μF bypass capacitor is recommended, as shown in Figure 8-1. The SCL, SDA,

and ALERT lines can be pulled up to a supply that is equal to or higher than VS through the pullup resistors.

For TMP175, to configure one of 27 different addresses on the bus, connect A0, A1, and A2 to either the GND

or V+ pin, or float. Float indicates the pin is left unconnected. For the TMP75, to configure one of eight different

addresses on the bus, connect A0, A1, and A2 to either the GND or V+ pin.

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TMP175, TMP75

SBOS288M – JANUARY 2004 – REVISED DECEMBER 2020

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Product Folder Links: TMP175 TMP75