Other Parts Discussed in Thread: LM5168, LM5169
Greetings:
I have an application that needs -28V supply to set the gate bias for a GaN switch. The application will consume next-to-nothing in current.
Is it possible to extend LMZ34002 to operate as a +12V to -28V converter? The datasheet front page reports that -17V is the max (or do you call that the min :)) but I do not specifically see anything in the datasheet that would limit this. Section 12.1 outlines the procedure to set the negative voltage. It seems like I could increase the Rset resistor to get to a higher negative voltage. Granted the current capability will drop per figure 33, but I would only need micro-amps. The absolute max ratings in the datasheet are a little cryptic with regard to Vout and an application with a negative output voltage; however, a total potential of 12 - (-24) = 36V seems to be less than the absolute max of 45V.
If this part is not appropriate, does TI have a different solution that is small and inexpensive?
--Russell
