SCL

ALERT

GND

2

6

1

A0

V+

3

5

Two-Wire

Host Controller

TMP175-Q1,

TMP75-Q1

SDA

5-k

Pullup Resistors

0.01-µF

Supply Bypass Capacitor

2.7-V to 5.5-V

Supply Voltage

A1

A2

4

7

8

TMP175-Q1, TMP75-Q1

www.ti.com

SBOS759 – NOVEMBER 2015

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. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The TMP175-Q1 and TMP75-Q1 devices are used to measure the printed circuit board (PCB) temperature of

compatibility, with the TMP175-Q1 allowing up to 27 devices on one bus and the TMP75-Q1 allowing up to eight

devices on one bus. The TMP175-Q1 and TMP75-Q1 both feature a SMBus Alert function. The TMP175-Q1 and

TMP75-Q1 require no external components for operation except for pullup resistors on SCL, SDA, and ALERT,

although a 0.1-

μF bypass capacitor is recommended.

The sensing device of the TMP175-Q1 and TMP75-Q1 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

Figure 13. Typical Connections of the TMP175-Q1 and TMP75-Q1

8.2.1 Design Requirements

The TMP175-Q1 and TMP75-Q1 devices requires pullup resistors on the SCL, SDA, and ALERT pins. The

recommended value for the pullup resistor is 5 k

Ω. In some applications the pullup resistor can be lower or

higher than 5 k

Ω, 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 0.1-

μF bypass capacitor is recommended, as shown in Figure 13. The SCL, SDA, and ALERT

Q1, to configure one of 27 different addresses on the bus, connect A0, A1, and A2 to either the GND or the V+

pin or float these pins. Float indicates that the pin is left unconnected. For the TMP75-Q1, to configure one of

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

Copyright © 2015, Texas Instruments Incorporated

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Product Folder Links: TMP175-Q1 TMP75-Q1