Please consider a charge pump integrator circuit. A pulse train switches in/out a current source which adds charge to a capacitor. If the voltage at the capacitor reaches a certain value, a feedback signal will turn on the second current source which removes a constant amount of charge.

Now, some of the pulses which add charge to the capacitor are quite narrow in width and finite operating times of the switch controlling the current source will not be fast enough to open and close in time. So, I lengthened/shortened each pulse by a constant value to avoid the problem mentioned above. However, I need to account for the changed length of each pulse by adding or subtracting this constant value from the capacitor before doing the threshold comparison and triggering the feedback signal.

Can anyone suggest a way to add/subtract this dc charge from the capacitor. For example, for a longer pulse (compared to the original one) I could switch in a current source with a lower current value, thus adding less charge over a longer time.

Any suggestions, hint, publications are appreciated.
Cheers,

Neoflash, thanks for the response. I'll certainly have a look at "gain boosting techniques" but I did not really want to correct for phase error.
As mentioned, I am just trying to subtract/add a constant dc term from the output of the capacitor before the 1-bit adc makes a decision. I want to do this in as simple way as possible, but I am lacking experience. Only circuit expensive ideas come to mind such as switching differenct current sources in, or changing the threshold of the ADC dynamically, or changing the ground value of the capacitor....... I was just wondering what else people might have used.

Cheers,