jefkat wrote on Dec 15th, 2011, 9:24am:Thanks Raja for the comments. Using pre-amplifiers is out of question as I have no current left . Not so sure about using decoupling caps. Decoupling caps will slow the ladder down further.
It is a power/speed/accuracy trade-off. The caps will reduce the glitch size, but the smaller glitches will take longer to settle to zero. For example, increasing the filtering might take a 100mV glitch that takes 100nS to settle and change it into a 1mV glitch that takes 10uS to settle. If your error tolerance is much more than 1mV you don't care how long it takes to settle so using caps might make sense in that case.
The down side to filtering is that the taps will never settle to their exact value. You need to check the average current coming out of the taps and make sure the IR drop isn't too large.
Code dependent currents can cause problems, but I wouldn't think it would be a problem at 5 bits, 8MHz. Check your average current for different codes and see how it will affect the average voltage of the taps of your ladder.