What Exactly is a Low drift sample and hold?

[Ian_Brooks]

I realize a sample and hold is used in digital control whereby the circuit holds the analogue value steady for a short time while the converter or other following system performs some operation over that held time.

However what does it mean by having low drift?

 

[Phrak]

You won't find anyone specifying a high drift sample and hold. It means the output doesn't change as much during the hold time as previously manufactured units in the same class.

 

[berkeman]

For low drift, you need a capacitor with low leakage (easy), low dielectric absorption (need the right material), and you need a high-impedance input to the buffer amp in the S/H.

 

[Ian_Brooks]

thanks