Inverting switching regulator with -80V DC output

Question

I need to design an inverting regulator with a +5V DC input and a -80V DC output. The maximum output current will only be 10mA. I cannot find any commercial switching regulators with -80V output specification. Can regulators that have -48V outputs be reconfigured to do -80V or should I continue to look for regulators that state that they can do -80V.

Answer 1

Here's a picture of an LT1425 flyback controller producing -9V. To get more voltage you increase turns on output winding of the transformer: -

This is a low power device that is probably suitable for your application but there may be others like LT3574 or LT3573: -

I know it's powered from 6V but it is producing 300V at 5mA and the positive output pin can be grounded. It has a minimum input supply voltage of 3V so should be capable of what you need with the appropriate turns on the secondary.

If you choose a design that has a flyback transformer it is inherently isolating input from output and you can choose to ground the positive output connection thus creating a negative output voltage.