SCL

GND

ALERT

2

4

1

ADD0

V+

6

3

5

0.01 µF

Two-Wire

Host Controller

TMP112

1.4 V to 3.6 V

SDA

Pullup Resistors

Supply Bypass

Capacitor

Supply Voltage

5 k

22

TMP112

SBOS473F – MARCH 2009 – REVISED FEBRUARY 2018

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Product Folder Links: TMP112

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Copyright © 2009–2018, Texas Instruments Incorporated

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 TMP112 family is used to measure the PCB temperature of the board location where the device is mounted.

The programmable address options allow up to four locations on the board to be monitored on a single serial

bus.

8.2 Typical Application

NOTE: The SCL, SDA, and ALERT pins require pullup resistors.

Figure 17. Typical Connections

8.2.1 Design Requirements

The TMP112 family requires pullup resistors on the SCL, SDA, and ALERT pins. The recommended value for the

pullup resistors is 5 kΩ. In some applications the pullup resistor can be lower or higher than 5 kΩ but must not

exceed 3 mA of current on any of those pins. A 0.01-μF bypass capacitor on the supply is recommended as

shown in Figure 17. The SCL and SDA lines can be pulled up to a supply that is equal to or higher than V+

through the pullup resistors. To configure one of four different addresses on the bus, connect the ADD0 pin to

either the GND, V+, SDA, or SCL pin.

8.2.2 Detailed Design Procedure

Place the device in close proximity to the heat source that must be monitored, with a proper layout for good

thermal coupling. This placement ensures that temperature changes are captured within the shortest possible

time interval. To maintain accuracy in applications that require air or surface temperature measurement, take

care to isolate the package and leads from ambient air temperature. A thermally-conductive adhesive is helpful in

achieving accurate surface temperature measurement.