I'm looking for a negative linear voltage regulator with at least a
-5 to -24 input voltage range and about 1 to 1.5 volts maximum dropout at 25 mA. I am aware of the LM2991 but am wondering if there is somethign available in a smaller package. Some are available with
-20V input capability but I need to -24. I've measured more than 2 V input-output difference required for the standard LM337.
One option is to use an LM337 to regulate to say -2.8 V, then use a doubler to change that to -5.6 V then use an LDO to regultate that to the final -4 V. Bit I'd prefer to use 1 device rather than 3.