![op amp offset voltage op amp offset voltage](https://app.na4.teamsupport.com/dc/784358/images/b1ac3815-c7dd-4171-90e3-fad59383d82e.png)
the circuit is intended to be "NON-INVERTING" amplifier, however an inverting configuration is mistakenly shown in the attachmentĬlick to expand.1. Is input voltage acceptable on the output pin of the DAC? Is there any way of "floating" the DAC output to high impedance? Even if it can be floated, it appears that the DAC output will be subjected to non zero voltages under normal operation of the amplifier. Once the calibration is over, the DAC is still connected to the input. The proposed schematic for calibration is attached below. The question is about a cost effective way of detecting the offset value without taking out the chip from the board (perhaps by adding some extra calibration circuitry and using the MCU) Updated - we can feed the offset to the EPROM, but for this we need to know the offset. Updated - do you mean my chopping off to higher frequency and filter. since the offset is multiplied by the gain of the amplifier, it will not be difficult to measure Positive offset can simply be detected by measuring it at the ADC. But DAC will produce a voltage in range of volts, and the offset is in range of millivolts, so do you think an op-amp with a "reduction" factor of about 1/100 should be a good idea? I got your idea of using a DAC, to detect negative offset. And yes, perhaps I'll have to apply some input voltage till the time it balances. I need to compensate the offset by feeding the offset value in the EPROM of the MCU.
![op amp offset voltage op amp offset voltage](https://www.ablic.com/en/semicon/wp-content/uploads/2013/02/17_opamp_zero-drift_Auto-zero-system_E.png)
measuring negative offsets can be even more painful. Since I do not have the luxury of a negative signal voltage.
#OP AMP OFFSET VOLTAGE MANUAL#
Is manual measurement and offset feeding in the MCU the only way?Ĩ. A direct measurement of offset through the MCU thus seems of no good as the MCU resolution itself it 2mV, and ofcourse we all know how reliable the LSB of a MCU based ADC is!ħ.
#OP AMP OFFSET VOLTAGE FULL#
The MCU has a 10bit resolution, with a full range of about 2V. Even a 5mV offset is unacceptable, and 2mV amplifiers, though still not readily acceptable, cost almost double!Ħ. I am sensing current, with a full range output of 50mV. I did not understand the concept of making DAC. There are around 8 op-amps on board and using lower offset amplifier literally doubles the cost. I just need to determine it so that the MCU 'knows' it.Ģ. Yes, you got it absolutely right, I don't mean to compensate it in real.