Question about Sample and Hold circuit

[ccw27]

Sample and Hold Circuit

Suppose all switches are closed during power down mode. What is the problem with this circuit? Also there is still input signal which is going into another circuitry.

Thanks

 

[yeewong_su]

Sample and Hold Circuit

Why are you keep all switches closed during power down mode?
we know that the control signal of the switches is diff. no overlapped

 

[nand_gates]

Re: Sample and Hold Circuit

Input signal will get shorted to GND!!

 

[ccw27]

Re: Sample and Hold Circuit

So what is usually done in SHA circuit during power down mode?

Thanks

 

[gevy]

Re: Sample and Hold Circuit

If the amplifier is in power down mode, the situation of switches is indifferent,
but output signal is uncertain.

 

[markty]

Re: Sample and Hold Circuit

Input signal will get shorted to GND!!

I think you can let the switch all off, or just stay in sample mode and power down the opamp.

 

[ccw27]

Re: Sample and Hold Circuit

Wouldn't hold mode be better? And does it matter what the output signal is since the ADC is also disabled?

Thanks

 

[minxin_zhou]

Re: Sample and Hold Circuit

Which situation may this case happen in? It seems the input signal is shorted to ground.