beautypg.com

0 applications circuits, Figure 6. centigrade thermostat, Lm20 – Rainbow Electronics LM20 User Manual

Page 7

background image

5.0 Applications Circuits

10090818

FIGURE 6. Centigrade Thermostat

10090819

FIGURE 7. Conserving Power Dissipation with Shutdown

10090828

Most CMOS ADCs found in ASICs have a sampled data comparator input structure that is notorious for causing grief to analog
output devices such as the LM20 and many op amps. The cause of this grief is the requirement of instantaneous charge of the
input sampling capacitor in the ADC. This requirement is easily accommodated by the addition of a capacitor. Since not all ADCs
have identical input stages, the charge requirements will vary necessitating a different value of compensating capacitor. This ADC
is shown as an example only. If a digital output temperature is required please refer to devices such as the LM74.

FIGURE 8. Suggested Connection to a Sampling Analog to Digital Converter Input Stage

LM20

www.national.com

7