Problem with opamps offset voltage when amp. is inverting

[sivamit]

opamp offset voltage

Hi friends,
I am designing a circuit where i am using op amp OP07 and my input is around 52mV. The amplifier is in inverting mode.The problem is offset voltage. im using trimmer pots as they have given . But even if the input is grounded the output voltage is always equal to VCc(saturated). No effect of pots. If i vary the pot value the o/p voltage is just changing +vcc to -vcc.
What cub be the reason for this?
Please Help....

 

[dfullmer]

Re: opamp offset voltage

What is your +VCC and your -VCC voltage exactly. If you are using this opamp with a single supply the action you are describing would happen. Also try the offset with a pot from null to null with +VCC on wiper as described in the data sheet.

Thats my two cents... good luck

 

[Kral]

Re: opamp offset voltage

sivamit,
Your offset nulling circuit is incorrect. Connect a 20K pot to pins 1, 8. Connect the wiper of the pot to +Vc. See the Maxim datasheet.
Regards,
Kral