-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

±50

±25

0

25

50

75

100

125

150

175

DUT Temperature (

ƒC)

C102

MAX LImit

MIN Limit

Trip Point

Trip Point - Hysteresis

(Temp. of Leads)

LM57-Q1

www.ti.com

SNIS191A – JULY 2015 – REVISED JULY 2015

Typical Application (continued)

8.2.1 Design Requirements

By simply selecting the value of two resistors the trip point of the LM57-Q1 can easily be programmed as

described in the following section. If standard 1% values are used the actual trip point threshold is not degraded

and stands as described in the Electrical Characteristics section ( ).

8.2.2 Detailed Design Procedure

To set the trip point:

1. Locate the desired trip temperature in .

4. Use only the EIA E96 standard resistor values from the list.

5. Use only a resistor with 1% tolerance and a temperature coefficient of 100 ppm (or better). These restrictions

are necessary to stay at the selected setting, and not to slip into an adjacent setting.

6. This is consistent with using resistors from the thick film chip resistors CRCW0402 family. These are

available with very small dimensions of L = 1 mm, W = 0.5 mm, H = 0.35 mm.

7. Note that the resistor tolerance does not diminish the accuracy of the trip point. As can be seen in the block

diagram these inputs drive the logic inputs of a DAC thus their tolerance does affect the trip point accuracy

unless the DAC setting slips into an adjacent level. See patent number 6924758.

8.2.3 Application Curves

The typical performance of the LM57TSPWQ1 temperature sensor output can be seen in Figure 22. Figure 23

Figure 23. Output Transfer Characteristic

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