I need to provide a backup voltage to a device, the current requirement is =
20uA. The device is battery powered. It is my understanding that zener re= gulator requires enough current to put the zener into regulation which woul= d be too much for our battery life.I know there are voltage references out there for this but they all seem to= be in the $2 range, a bit pricey.
Any elegant solutions?
Thanks
Rich
20uA. The device is battery powered. It is my understanding that zener regulator requires enough current to put the zener into regulation which would be too much for our battery life.
in the $2 range, a bit pricey.
Since you have no requirements for nominal voltage, accuracy, stability, size, weight...and no notion of where the power comes from, I'd just use an old car battery. Even a dead one should do 20uA for a long time.
The hardest part of a solution is defining the problem.
I know there are voltage references out there for this but they all seem to be in the $2 range, a bit pricey.
Any elegant solutions?
Thanks
Rich
CR2032 coin cell ?
MCP1700 regulator ? has 1ua quiescent current...
At 28 cents in quantity at Mouser, the MCP1700 looks pretty hard to beat.
20uA. The device is battery powered. It is my understanding that zener regulator requires enough current to put the zener into regulation which would be too much for our battery life.
in the $2 range, a bit pricey.
Depends on voltage needed. Use a diode OR gate, where master supply voltage being slightly higher than the backup battery which is lithium.
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