GND

V+

I/O1

I/O2

Sensor 1

R1

ALERT1

R2

ALERT2

TMP107

TX

RX

UART

100

4.1 k

10

1.7 V to 5.5 V

V+

GND

7

1

3

5

Sensor 2

TMP107

2

6

8

4

GND

V+

I/O1

I/O2

R1

ALERT1

R2

ALERT2

0.1 F

MCU

7

1

3

5

2

6

8

4

Switch / Control / LED

Switch / Control / LED

GND

V+

I/O1

7

1

I/O2

3

5

Sensor 1

R1

ALERT1

R2

ALERT2

TMP107

TX

RX

UART

100

4.1 k

10

1.7 V to 5.5 V

2

6

8

4

V+

GND

Sensor 2

TMP107

Sensor N

TMP107

GND

V+

I/O1

I/O2

R1

ALERT1

R2

ALERT2

GND

V+

I/O1

I/O2

R1

ALERT1

R2

ALERT2

ALERT1

ALERT2

INT2

INT1

MCU

7

1

3

5

2

6

8

4

7

1

3

5

2

6

8

4

TMP107

www.ti.com

SBOS716B – MAY 2015 – REVISED SEPTEMBER 2015

Typical Applications (continued)

8.2.2 Connecting ALERT1 and ALERT2 Pins

As described in the ALERT1, ALERT2, R1, and R2 Pins section, the TMP107 contains internal 100-k

Ω pullup

resistors connected between pins ALERT1 and R1, and pins ALERT2 and R2. Connect R1 and R2 to V+ in order

to enable the internal pullup resistors. Figure 42 shows a schematic example of how to connect these pins for

multiple TMP107 devices in a daisy-chain configuration.

Figure 42. Connecting ALERT1 and ALERT2 Pins

8.2.3 ALERT1 and ALERT2 Pins Used as General-Purpose Output (GPO)

The TMP107 alert pins are also used as a GPO to control external switches or LEDs. This feature is useful in

applications wherein the wiring between general-purpose output lines from the microcontroller or host to a control

switch or LED can be eliminated by communicating through the I/O pins of TMP107. To configure the ALERTx

pins as a GPO, program the high-limit register to the highest temperature (7FFCh) and the low-limit register to

the lowest temperature (8000h). This programming disables the ALERTx pins from performing high- and low-limit

temperature controls. The configuration register polarity bits (POL1 and POL2) are used to toggle the ALERTx

pin output. The ALERTx pins are open-drain outputs; therefore, make sure the R1 and R2 pins are connected to

the supply voltage, as shown in Figure 43.

Figure 43. ALERT1 and ALERT2 Pins Used as General-Purpose Output

Copyright © 2015, Texas Instruments Incorporated

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