7.0 Applications Circuits

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FIGURE 4. Celsius Thermostat

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FIGURE 5. Conserving Power Dissipation with Shutdown

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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 LM94021 temperature

sensor and many op amps. This requirement is easily accommodated by the addition of a capacitor (C

depends on the size of the sampling capacitor and the sampling frequency. Since not all ADCs have identical input stages, the

charge requirements will vary. This general ADC application is shown as an example only.

FIGURE 6. Suggested Connection to a Sampling Analog-to-Digital Converter Input Stage

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