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simple solution to switch power on and off using pushbutton

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Newbie level 3
Aug 31, 2009
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I am looking for a simple solution to switch power on and off using a pushbutton. I have to following requirements:
- low power in standby/off
- use a pushbutton to switch on
- to switch off the uC pulls an GPIO low, or the on/off pushbutton is pressed for a few seconds
- the powerswitch shall have low on-resistance
- the switch shall provide at least 500mA current
- two power sources shall be used (battery or wall power supply); use the battery only, if the other supply is not available
- would be nice, if a battery charger would be integrated
- would be even nicer, if 3 power supplies are nicely supported (USB or external power)

Does anyone have an idea? I am looking for integrated circuit, for this task.


Re: Powermanagement

I didn't get ur req ( esp last 3).can you please elborate it?

Re: Powermanagement

What I am looking for is simple. I have a battery powered device, which now uses a switch to power it on and off. What I want is to use a pushbutton to switch in on, and the uC to switch it off. Because the software on the uC may hang, I want to be able to press the "on"-pushbutton for a few seconds, to switch the device off, also.

The device is battery powered, but is connected to a wall plug power supply, if so, I'd like to detect this by the uC and want to use the external power supply instead of the battery. Would be very nice, if the battery could be charged in the device.

In the off state the device should consume as less power as possible!

All this power management should preferably be done by a single IC - this is what I am looking for!

Thanks in advance.

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