Some EL phosphors change color with frequency. I would like to know if I can drive the REL_Osc pin with logic levels from an external oscillator (MPU PWM) to control the EL drive frequency.
Hello, changing resistor Rel for the REL_Osc pin changes the driving frequency of the EL Driver. You can use the following equation to determine this:
I’d like to change the frequency under control of a micro. To change resistance with a digital signal I’d have to use some sort of a digital potentiometer which adds costly electronics. I was hoping it might be possible to force a frequency with a square wave from the micro. Since the oscillator can be enabled and disable with a digital signal on the Rel_osc pin, I was hoping I could force a frequency with a digital signal on that pin.
I am not sure the pin configurations would allow for a PWM input since the driver frequency would need to be changed with Rel_osc through changing the R_EL resistor.
Would you be open to using an LED Driver that can take a PWM input? Do you have an evaluation board of the MP3802 to run tests or are you working with a part with your own schematic?
I don’t think an LED driver would handle EL voltages.
I have been using a Microchip HV816 which has EL frequency and audio (brightness) inputs, but I’m searching for an alternative to redesign my board around.