Hi, I am getting lots of noise on the digital inputs. See the schematic below. I have a switch that is remote and the 2 wires for the switch run in the same bundle as high voltage 240Vac wires.
I have a bi-directional TVS diode (Voltage_reverse_standoff=5.8V, voltage_breakdown_min=6.45V, voltage_clamping_max=10.5V).
I also have an RC filter with R1 and C1 and a cutoff of 160 Hz. I also added C2 (0.1uF) for extra filtering.
I am using a MCP23S17 as an IO expander for my PIC microchip.
I have determined that the noise is getting into the system from only this remote switch that I have and it is corrupting data on an LCD.
Anyone know how to better filter this digital input line?
Thanks.
I have a bi-directional TVS diode (Voltage_reverse_standoff=5.8V, voltage_breakdown_min=6.45V, voltage_clamping_max=10.5V).
I also have an RC filter with R1 and C1 and a cutoff of 160 Hz. I also added C2 (0.1uF) for extra filtering.
I am using a MCP23S17 as an IO expander for my PIC microchip.
I have determined that the noise is getting into the system from only this remote switch that I have and it is corrupting data on an LCD.
Anyone know how to better filter this digital input line?
Thanks.