Autozero and chopper stabilizer ckt design using ICS and discrete components

Thread Starter

Gvasu

Joined Mar 20, 2022
1
Now, I am working with signal condition circuit (wheate stone full bridge configuration)..my amplifier input range is +-10mv. Expected output is +-5v..during the test condition I am facing two problems.
1. At zero input case, getting 10 to 20mv as a offset and also varying dynamically..
To mitigate the above problem go for(book knowledge)
1. Auto zero
2. Chopper stabilizer
Is it possible to implement above two concepts with ICS and discrete components.any one help me to design above ckts..
 

crutschow

Joined Mar 14, 2008
30,127
Generally stray capacitive coupling will make a discrete implementation problematic.
Better is likely to use a chopper stabilized/auto zero op amp.
They can have offsets in the low microvolt range.
 

DickCappels

Joined Aug 21, 2008
8,838
A chopper stabilized opamp is probably the best choice. Depending upon how small you need the offset to be you might find a pre-trimmed opamp to be suitable. One example that comes to mind is the ROHM LMR1801G with an offset of 5 µ, and very cheap for that kind of performance (Less than US $1.00 for a single device).

 

crutschow

Joined Mar 14, 2008
30,127
The offset of a good chopper-stabilized IC op amp is so low that thermo-electric effects, such as from a copper-solder joint, will likely dominate the offset voltage.
 
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