Sample and Hold Circuit

From our information about ADC, we are  trying to convey the information about analog to digital conversion. The very fundamental of conversion is SAMPLE AND HOLD CIRCUIT.

Let us see its working

 

It contains Input amplifier, Energy storage device (nothing but capacitor),Output buffer, Switching circuits.

Its specification were    Track mode, Track to Hold transition, Hold mode, Hold to track transition

In TRACK MODE: voltage on the capacitor follows the input signal or we can say track the input signal

In HOLD MODE: switch is opened, and capacitor retains the voltage present before it was disconnected from the input buffer.

Simply we can say the capacitor holds the voltage value measured until a new sample is acquired.

The waveform will be..