BQ25504 Energy Harvester

Energy harvester based on TI chip BQ25504, following typical application reference. Project may develop to incorporate heatsink designs and other boards that may use this as a coldstart device.

***SEE ATTACHED SPREADSHEET FOR CALCULATOR BQ25504_DESIGN_HELP_V1_2.xlsx ***
***RESISTORS ARE SET FOR SOMETHING AROUND 2.5V, BE WARNED!!***
***CHANGE RESISTOR VALUES FOR YOUR APP AND RTFM***
***BONUS POINTS FOR X5R CAPACITORS IF YOU NEED LOWEST LEAKAGE CURRENTS***

*** PROJECT IS IN PROGRESS ***
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Update Sept 17-2024
- Tested boards today, GND plane is a bit of a pain without a preheater but it is manageable. might update or add option for a 4layer with cleaner gnd plane routing since 2 layer necks down a lot in some areas while trying to keep clearances high to prevent any possible leakage currents.
- Voltage came out to 2.58V for my first board, again please select your resistors for the voltage desired.
- Cold start function was interesting, worked a bit lower than datasheet spec, all good. Had fun playing around with the optimal distance between heatsources or coldsinks to maintain differential.
- Tested just with a blue LED in parallel with the power supply since mine is set to 2.6V or less it should be fine without a current limiting resistor for blue.
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