I am trying to figure out how to make the 3.2V output of my PCF8574 I/O Expander chip drive a -15V to controle a bunch of J111 JFET switches.
I'm looking for cheap and small parts count for this.
Would I just use an opto-coupler or just a transistor and if so whats the best way to wire it up.
I'm looking for cheap and small parts count for this.
Would I just use an opto-coupler or just a transistor and if so whats the best way to wire it up.