Can you tell whether you work in a product design company, or an engineering company?
Does that come from clients?
I used the same 3-in-1 latch circuit for power on/off, pairing, and software power off for 12 years.
A good enhancement mode NMOS FET can be as good as a physical switch at low voltages.
If you really need nano-amp level leakage current AND very low drop, you can consider turning to beefy depletion mode devices, which gate the user will discharge with the button press. A nice benefit is that you can directly sense the button press with an MCU.
I once even did a bluetooth mouse with this "hardware" switch, and a graceful shutdown: we sense voltage on the buck capacitor, and detect when the battery disconnect triggers.
The few microfarads in the capacitor are enough to send the last update with the 0% battery level, and a disconnect command.
> Can you tell whether you work in a product design company, or an engineering company?
Both! There aren't many of those out there, so I probably just outed myself. Oh well. Keep it quiet please?
> A good enhancement mode NMOS FET can be as good as a physical switch at low voltages.
Yes, it can work very well. You are correct that it need not be a physical switch. But it still does nothing if it is never brought out to the device's interface. And physical switches are still preferable if the software is broken, as it often happens to be during development.
> you can consider turning to beefy depletion mode devices
Depletion mode devices are not cost effective. If you think they are, point me to one cheaper than the LND150. (And, yes, I do know how to use them. Many designers do not.)
Does that come from clients?
I used the same 3-in-1 latch circuit for power on/off, pairing, and software power off for 12 years.
A good enhancement mode NMOS FET can be as good as a physical switch at low voltages.
If you really need nano-amp level leakage current AND very low drop, you can consider turning to beefy depletion mode devices, which gate the user will discharge with the button press. A nice benefit is that you can directly sense the button press with an MCU.
I once even did a bluetooth mouse with this "hardware" switch, and a graceful shutdown: we sense voltage on the buck capacitor, and detect when the battery disconnect triggers.
The few microfarads in the capacitor are enough to send the last update with the 0% battery level, and a disconnect command.