-75

-50

-25

0

25

50

75

100

125

150

Temperature (°C)

6

5

4

3

2

1

0

VS = 5.5 V

TMP20

V+

GND

VOUT

MSP430

ADC

CBP

CF

V+ (1.8 V to 5.5 V)

Copyright © 2017, Texas Instruments Incorporated

12

TMP20

SBOS466B – DECEMBER 2009 – REVISED DECEMBER 2018

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Copyright © 2009–2018, Texas Instruments Incorporated

8.2 Typical Application

Figure 12. Suggested Connections to a MCU ADC

8.2.1 Design Requirements

ADCs that are found in microcontrollers (such as the MSP430 line of microcontrollers) take charge during the

sampling phase. A high sampling frequency results in too much charge pulled into the ADC and sags the output

voltage of the TMP20, which results in a reading that is hotter than normal. To mitigate this, place a capacitor

(CF) between the TMP20 and the ADC. The capacitor functions as a charge reservoir.

8.2.2 Detailed Design Procedure

The size of CF depends on the size of the internal sampling capacitor and the sampling frequency. The charge

requirements may vary because not all ADCs have identical input stages. This general ADC application is shown

as an example only.

8.2.3 Application Curves

Figure 13 shows the quiescent current versus temperature.

Figure 13. Quiescent Current vs Temperature