sample and hold
This is the output of both track and hold and sample and hold.
But when I searched for its circuit I am getting the circuit I have shown below for both. So my question is if the circuit for sample and hold and track and hold are the same then how is the difference between the two getting reflected in the circuit? Is the control signal input different for both and if it is, then how is it different?
A peak detector is something of a sample and hold that samples all the time, and holds the peak:
Follow the input with this, and connect the output to your ADC. Make C significantly larger than the capacitance used by your ADC's sample and hold, or follow it with a buffer, so the voltage across C doesn't sag as you read it.
Trigger an ADC reading just after the event happens, and when it's done, close the switch to reset the peak, or make the switch a resistor forming an RC time constant significantly longer than the time it takes to measure the peak but significantly shorter than the interval between peaks to accept a little error but avoid the need to reset the peak detector.
Think of the circuit as voltage source charging the capacitor through the output resistance. Will you be able to charge the capacitor in 1us?
Best Answer
There is no difference. The two terms are used interchangeably:
A capacitor takes time to charge or discharge to the level of the incoming signal. This time is the track time (aka the sample time). The amount of time taken depends to a large extent on both the size of the hold capacitor and the output impedance of the device you are sampling.
Note the word "ideal" in the description of your waveform a. Ideal never exists in the real world, so you have to add the "tracking" period to be able to sample the waveform.
That is why there is only one circuit shown for the input, because they are both the same thing.