I am working on a circuit based on the LT1930 (DC634A) to boost input voltage between 30 and 90V.
I would like to take this boosted voltage and double it via a Dickson charge pump to the required ~160V.
This would allow for a variable voltage output between 60-180V. The current draw from this boosted supply is very low, ~1uA.
A logic level PWM signal will drive the Dickson charge pump.
I am having difficulty figuring out how to drive the boosted voltage through the C1 based on the PWM clock. I have setup a NPN driven by the PWM signal to switch a PNP MOSFET to high side switch the boosted HV.
When I run simulations, the output voltage does not double.
R1 and R2 are set to give a Vgs ~10V, but then this causes the drain on the FET to only vary between 80 and 70V.
I am open to suggestions, including completely wiping this circuit and using something else to generate a controllable ~100-180V.