I need to charge a 1000uF 400V capacitor bank off of a 7V LiPo battery within roughly 5 seconds, and have the circuit be as small and light weight as possible. With a constant voltage supply and a resistor to limit the current, the peak current when the capacitors are discharged is around 200mA, and with a constant current power supply the peak current is around 100mA. The constant current supply would also make other parts of my circuit easier, so I would like to have the power supply current limited if possible.
The flyback converter seems like the best topology so far, but how does the flyback compare to other topologies like cascaded boost and boost with autotransformer converters for this kind of voltage?
Would constant current flyback controllers like the UCC28700 and LT3798 work for this? All the ones I can find seem to be designed for stepping down voltages from rectified AC power to a low voltage DC, and I'm not sure if it is possible to run the the opposite way.
There are a few other questions on here about high voltage supplies, but they're all limited to current levels in the uA, so I'd appreciate some direction.