- Single ended speed sensor
- Output voltage: 0V to 30Vpp
- Output frequency: 0Hz to <60Hz
My speed sensor output has a varying DC offset, primarily at low speed. MAX9926 is used in mode A2 as a ZCD. The input also has some noise and is distorted as shown below. MAX9926 is not able to convert low frequency (low speed) inputs because of this offset. How can I remove this offset so that the signal is less attenuated and is understood by MAX9926? Tried a RC HPF but the input seems attenuated very much and is not readable by the chip.
When a capacitor was added in series to the input line to remove DC offset, 2.2V read on IN1+ pin of MAX9926, was added to the sensor input, shifting the offset to a much higher value. Need an input on a way to deal with this.
The ripples in input is also affecting the output and making it erratic. Can it be configured in a better way to deal with such ripples and varying offsets?
Requesting urgent attention.
A. Sensor outputs
B. Schematic
