There is an input to ADC of Micro controller, the ADC level is 0 to 3.3 V. The input is phase current signal of the motor, from the current sensor.
The output is -1.65 to 1.65 V. Therefore, the signal has added an offset of 1.65 V by pull up to be in the proper range. After trying to varied input as sine wave, the converted digital values show that the frequency is changed as the input, but the amplitude is not really changed. How can this problem be solved? The resolution of ADC is already set to maximum (12 Bit).
The output is -1.65 to 1.65 V. Therefore, the signal has added an offset of 1.65 V by pull up to be in the proper range. After trying to varied input as sine wave, the converted digital values show that the frequency is changed as the input, but the amplitude is not really changed. How can this problem be solved? The resolution of ADC is already set to maximum (12 Bit).