Sample & Hold circuit

Thread Starter

perzade

Joined Jan 30, 2011
4
I m sending temperature readings to uC thru ADC0804 & sensor is LM35. Do I require a S/H circuit as I hav directly interfaced LM35 to ADC or does it have internal S/H circuit??Plz reply asap
 

Ron H

Joined Apr 14, 2005
7,014
I m sending temperature readings to uC thru ADC0804 & sensor is LM35. Do I require a S/H circuit as I hav directly interfaced LM35 to ADC or does it have internal S/H circuit??Plz reply asap
LM35 does not have an internal S&H. You shouldn't need one.
 

crutschow

Joined Mar 14, 2008
23,729
S/H circuits are needed if the measured voltage is rapidly changing and you need to capture the voltage at a particular point in time so the A/D has a stable voltage to convert. For a relatively steady voltage, such as the output of the LM35, a S/H is not needed as Ron H noted. But many A/Ds already have a built-in S/H (stated in the data sheet) so, even if you did need a S/H, you wouldn't have to add an external one.
 
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