Debounce mgmt chip with programmable duration & zero standby current?

[arnoldw]

I am about to start a simple wireless project. Basically, when the user pushes or releases a button on a remote unit, some data should be transmitted to a main unit. Thus, when the button is pressed or released, I need power for about two seconds on the remote unit. At all other times, I want the remote unit to consume absolutely no current at all. Does a chip suitable for this exist or do I need to design some clever circuit myself?

 

[MacGyverS2000]

Microchip has a few useful micro/transmitter combos for a couple of bucks each, though your absolute zero requirements will require a small circuit of your own design to remove power from the circuit (is it worth the trouble when the chip draws less power than a battery's self-discharge rate?).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[arnoldw]

I am thinking of using Microchip MRF24J40MA which draws 2 microAmps when in sleep mode. I think this is too much and I would like to disconnect power from the all chips and components completely.

What chips are available to prevent bouncing from a mechanical switch? Can a duration be programmed on these chips?

 

[MacGyverS2000]

I believe the MC transceiver chips have switch debouncing built in as their main use is remotes. I find it hard to believe your application can't handle 2uA as a drain current... a remote will last for many many years at that level of drain, and it will most likely die from the battery self-discharging faster than the chip would ever do it.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Compositepro]

A normally open switch and suitable capacitor to apply the power to your circuit should be all that you need. Your description sounds a lot like a garage door opener.

 

[arnoldw]

Ok, thanks for your help.

 

[zappedagain]

Linear Tech just introduced a device that gets power from vibration, so it can run without a battery in low power consumption applications.

I believe Texas Instruments' MSP430 family is still the best for low current consumption applications.

John D

 

[Skogsgurra]

I wouldn't be concerned about 2 uA at all. We have designed devices for bearing temperature supervision that have around 12 uA continuous battery drain. Sometimes we get phone calls from people that have forgotten there is a battery inside. That tends to be five to six years after delivery. At 2 uA, you shouldn't have any worries.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[arnoldw]

I will use sleep mode, 2 uA isn't so bad after all. Thanks to everybody who contributed to this thread.