How many projects did I need the same button to do both turn on and turn off the device? I’ve made the soft latching circuit from Dave Jones’ EEVblog #262 – World’s Simplest Soft Latching Power Switch Circuit, but it is so many components. So many footprints. Good news is there is a simple solution, the MAX16054AZT+T. Pressing the button once will toggle the logic high on the OUT and !OUT pins.
And best part is, it’s tiny.

The chip and resistor are small enough allow the board to be flipped. There are labels for the pins and a small white pad for any identification markings.


Now to build up a circuit to test everything. It has a operating Vcc range up to 5.5v, so I will use 5v to supply the MAX16054AZT+T and an Arduino Nano switched on and off by a P-channel MOSFET. Here is the circuit I built.

MAX16054AZT+T in action.
Thanks for following along! This is going to be a very useful chip and I am excited to use it in future projects. If I were to change anything, I would add a footprint for a switch on the PCB. I am going to look for a good matching P-channel SMD MOSFET and the whole board could just be plugged in to the breadboard or pin header.
I have a few more new chips to get reflowed to a PCB and play with so keep any eye out for new posts! Please check out my recent posts to the right and thanks for following along!