I want to create a 5V/1A regulated power supply from a 6.3V RMS input. I can get a regular diode bridge in a 4 pin DIP package, but it is marginal and my simulations and actual tests show that the forward voltage drop is too much under even a light load. My simulations show that a Schottky diode bridge works OK, and I can get an SMD 4 pin package with a total forward voltage drop of around 0.8V. However, I have seen designs for active MOSFET full-wave rectifiers, so I figured I might as well try to go that route.
I came across two potential ICs to help. One is the LT4320 and the other is the FDMQ8205. The LT4320 uses external FETs, but the killer seems to be that the minimum output voltage is 9V. The FDMQ8205 has internal FETs, but I can't figure out how I would use it in a regular full-wave bridge rectifier. It has AC inputs and gate drive inputs and I'm not sure what the gate drive inputs should be. In note 4 in the datasheet <https://www.onsemi.com/pub/Collateral/FDMQ8205-D.pdf>they show a wiring diagram that connects the AC input to the gate inputs, but I can't tell if that is a topology that would provide full wave rectification, or if it is just something used for testing. Does anyone have any experience with active bridges at these voltages, or with these ICs? Is there an alternative I should be looking at? Should I just stick with the Schottky diode version? -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/09f8e9f7-3f34-4f89-811a-e12901b4d631%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
