Other Parts Discussed in Thread: CC115L, TPS61299, TPS63900,
Hi,
we plan a small keyfob with a MCU and CC115L RF, driven by a CR2032 coin cell. RF pulses will be at about 20-50ms long.
As CC115L consumes up to 30mA, any native CR2032 will 'die' within a few hundred cycles: internal resistance increases fast and under load output voltage will drop fast below 2V.
Now we want to operate CC at about 2.2V, which helps to some extend (~25% less current than at 3.3V, with a few less dB PA).
In addition such a boost circuit like this TPS might help: set to e.g. 2.2V VOUT, with the coin cell supplying 3V -> down to 1V, its always guaranteed that my circuit is provided with 2.2V.
The power consumption of the circuit will vary between some uA in sleep mode, waiting for a button press; a few mA if the MCU is operating alone and up to ~25mA including the RF.
Questions: is this TPS (due to budget we can't afford anything more expensive than this one) the right choice to help us out?
And: as long as the coin cell deliver more than 2.2V, the TPS is in DOWN-mode and 'destroys' the valueable energy in its internal circuits - I can't believe that this would be the right strategy...
So please advise
Thanks in advance
