Thermal Diodes

OUT

GND

LMT84, LMT84-Q1

www.ti.com

SNIS167C – MARCH 2013 – REVISED OCTOBER 2015

8 Detailed Description

8.1 Overview

The LMT84/LMT84-Q1 is an analog output temperature sensor. The temperature sensing element is comprised

of a simple base emitter junction that is forward biased by a current source. The temperature sensing element is

then buffered by an amplifier and provided to the OUT pin. The amplifier has a simple push-pull output stage

thus providing a low impedance output source.

8.2 Functional Block Diagram

Full-Range Celsius Temperature Sensor (

−50°C to 150°C)

8.3 Feature Description

8.3.1 LMT84/LMT84-Q1 Transfer Function

The output voltage of the LMT84/LMT84-Q1, across the complete operating temperature range, is shown in

Table 1. This table is the reference from which the LMT84/LMT84-Q1 accuracy specifications (listed in the

Accuracy Characteristics section) are determined. This table can be used, for example, in a host processor look-

up table. A file containing this data is available for download at the LMT84 product folder under Tools and

Software Models.

Table 1. LMT84/LMT84-Q1 Transfer Table

TEMP

TEMP

TEMP

TEMP

TEMP

(°C)

(mV)

(°C)

(mV)

(°C)

(mV)

(°C)

(mV)

(°C)

(mV)

-50

1299

-10

1088

30

871

70

647

110

419

-49

1294

-9

1082

31

865

71

642

111

413

-48

1289

-8

1077

32

860

72

636

112

407

-47

1284

-7

1072

33

854

73

630

113

401

-46

1278

-6

1066

34

849

74

625

114

396

-45

1273

-5

1061

35

843

75

619

115

390

-44

1268

-4

1055

36

838

76

613

116

384

-43

1263

-3

1050

37

832

77

608

117

378

-42

1257

-2

1044

38

827

78

602

118

372

-41

1252

-1

1039

39

821

79

596

119

367

-40

1247

0

1034

40

816

80

591

120

361

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Product Folder Links: LMT84 LMT84-Q1