I'm trying to find the best way to derive a -15v rail for audio use.
Maximum current needed by the -15v rail will be -80mA
Source is 19.5v dc laptop supply.
LMZ34002 will take 19.5v down to -17v and then I will use TPS7A33 linear regulator for -15V
Second option is a charge pump from 19.5v to -18.33V at 100ma maximum draw and then use TPS733 to regulate for -15V
It will be first attempt using hot air so I don't know if I will be able to reflow the simple switcher properly with the multiple pads and thermal vias.
Disadvantage of the charge pump is it's getting close to current limits and I was informed that charge pumps are not good for transient spikes.
Any advice or is there a better way that I haven't thought of?
