0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

±50

0

50

100

150

TEMPERATURE (

ƒC)

C001

GND

OUT

Input

Pin

LMT87

Reset

Sample

Simplified Input Circuit of

SAR Analog-to-Digital Converter

+2.7V to +5.5V

13

LMT87, LMT87-Q1

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SNIS170D – JANUARY 2014 – REVISED JUNE 2017

Product Folder Links: LMT87 LMT87-Q1

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Copyright © 2014–2017, Texas Instruments Incorporated

9 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.

9.1 Application Information

The LMT87 features make it suitable for many general temperature-sensing applications. It can operate down to

2.7-V supply with 5.4-µA power consumption. Package options like the through-hole TO-92 package also allow

the LMT87 to be mounted onboard, off-board, to a heat sink, or on multiple unique locations in the same

application.

9.2 Typical Applications

9.2.1 Connection to ADC

Figure 13. Suggested Connection to a Sampling Analog-to-Digital Converter Input Stage

9.2.1.1 Design Requirements

Most CMOS ADCs found in microcontrollers and ASICs have a sampled data comparator input structure. When

the ADC charges the sampling cap, it requires instantaneous charge from the output of the analog source such

as the LMT87 temperature sensor and many op amps. This requirement is easily accommodated by the addition

9.2.1.2 Detailed Design Procedure

ADCs have identical input stages, the charge requirements will vary. This general ADC application is shown as

an example only.

9.2.1.3 Application Curve

Figure 14. Analog Output Transfer Function