Help needed in designing DAC ..

Status
Not open for further replies.

nandithaa_m

Junior Member level 3
Joined
Jan 2, 2008
Messages
27
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
USA
Activity points
1,473
I am trying to design a 3 bit DAC which should work at 10 MHz. I started designing by using R-2R ladder. I gave the inputs such that digital state changes from 000 to 111 for every 10 MHz. I am unable to get the exact output. If I slow down the clock its working (suppose to 1 MHz, 100k). Its working. I can see steps.
I think the problem is with the loading of the opamp.
What should I do if want to shift the pole of the opamp to higher frequencies.
PLZ help me.
I am attaching the circuit diagram as well as the simulations below.

and one more question?
how to add a follower to this circuit (to the o/p of opamp). The circuit should drive 5pf load.
 

Status
Not open for further replies.

Similar threads

Cookies are required to use this site. You must accept them to continue using the site. Learn more…