Hi,
I am working on a board where I need +/- supplies to a couple of op-amps.
I am trying to use the MAX865 dual-output charge pump. It will nicely double the 3.3V supply and provide positive and negative supplies of double the input, i.e. +/- 6.6v.
I can make it work - some of the time. It will successfully run on some board, while on other boards it will not work properly and outputs +2.7 and -1.4 while being fed with 3.3v.
Everything else on these boards runs fine, STM32L4´s, digital pots, input mux, all I2C devices etc.
Does anyone have experience with the MAX865 and can share some advice on how to make it work reliably?
I have attached a snapshot from the relevant area of my board.