Instr. Amp. offset control cirquit

Thread Starter

Crowbar

Joined Dec 19, 2006
32
Hi, need an output INA voltage adjustment in a range of few mV. I must take into consideration charge pump power supply noise and cause cirquit operates with 30mkV values- think that such scheme works, isn't it:
 

Distort10n

Joined Dec 25, 2006
429
If you are asking if the circuit from the PGA204/05 Datasheet will work to adjust offset for instrumentation amplifiers, then yes. What is the specification on the charge pump? Noise should never be induced into the reference. Easier said than done.
 

Thread Starter

Crowbar

Joined Dec 19, 2006
32
Charge pump will give ripple near 10mV into power supply rails. We can't connect 10KOhms pot directly to power supply rails cause we will have ripple affecting A3 + input in INA- that's why I asked about cirquit using REF200(it gives 100uA +/-0.2% output with max 1nA noise).
 

Thread Starter

Crowbar

Joined Dec 19, 2006
32
Is it true that REF200 provides some sort of current stabilisation(when we see on simplifed cirquit diargram)?
 
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