how to implement this circuit?

[samuel]

how to implement V(t1)-V(t2)?

thanks.

samuel.

 

[raduga_in]

Try charging/ discharging a capacitor with a current source

 

[bobchentan]

use kind of inverter?

 

[samuel]

i mean how to correlated double sample?

V(t1)-V(t2)>1.8

 

[johnyaya]

I'm not certain I understand your request. Do you want to know the voltage at two descreet points in time, or do you want to generate the waveform given V1 and V2 and their times?

 

[samuel]

waveform is kown.

Now, i want to get the difference of the two sampled voltage value.

thanks.

 

[Yang]

Using ADC converter, and then comparing by MCU.

 

[raduga_in]

Now I got your question. Here is a crude method ..
charege a capacitor at instance t1 and at t2 ..
apply this to a difference amplifier ...

provided RC time constant of the ckts for sampling
should be very small ..

Raduga

 

[samuel]

but how to implement diffrential structure amplifier?

V(t1)-V(t2)>1.6

can differential amplifer do the substraction of large voltage？

 

[johnyaya]

What accuracy & precision do you require? Using an MCU (microcontroller) can be a very easy (ok, relatively easy) way to achieve this. Many MCU's have analog to digital converters (ADC) already built in, ranging from 8-bit to 20-bit resolution. The timing can be in the nSec range. The output can be a serial stream (COM port) or even USB without too much effort. Is using an MCU a viable option?

 

[markjiang]

using the swithed-capacitor technique.

only need one capacitor and four swithes and four phase clock.

if you want to amplify the difference, you need to use integerator to flow the sample as a ration amplificaton with capacitor ratio.