OPA336 Single supply question

vanush vaswani

Other Parts Discussed in Thread: OPA336, TINA-TI

Hi,

I'm trying to make a biopotential amplifier. The first stage (instrumentation amplifier) should have a gain of 5. The second should be a noninverting amplifier with a gain of 100. How can I make a single supply noninverting amplifier with OPA336? The problem I'm having is that the output of the first stage (in amp) has a DC level of 2.5 V (which is Vcc/2) as I'm using a virtual ground.

over 13 years ago

0 Edwin Krasser over 13 years ago

Expert 2420 points

Hi!

Simply use a non inverting amplifer with the feedback voltage divider connected to your 2.5 V source. This must be the same as the 2.5V reference used for the instrumentation amplifier because offset voltages really matter if you want a gain factor of 100.

       | \
in---------|+ \
       --|- /--o---Out
   | | /   |
   |   |
V2.5--R2-|--R1---|

Best regards,
Edwin Krasser

0 Marek Lis over 13 years ago in reply to Edwin Krasser

TI__Guru 71711 points

Edwin,

Below please find a simple OPA336 single supply circuit configuration for G=+100 with simulation result. I have also attached Tina-TI schematic for your convenience.

opa336 single supply G=100.tsc

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OPA336 Single supply question