EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: implor on January 16, 2020, 09:44:06 pm
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I have been looking around for a switching super simple lithium ion/polymer charger IC.
Basically I want a linjer IC simplicity with a switching efficiency.
Requirements:
in 4.5-5.5V
min 1A out
4.2V singel cell
switching (>80 efficiency)
Current limit set with resistor.
Anything suggestion?
I have spent about a day looking at options but nothing is perfect. It's to complex require some setup/programming or something else.
Original idea was to use a linjer charger but when I do the calculations it looks quite bad (1.68 watt loss). But I know by experience that estimate cooling factor of a pcb is not easy. You need to test it.
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Try the Texas Instrument's BQ24250. It will meet your specs and more. A well designed chip which I have used in my commercial designs. You might want to consider a separate BQ or other fuel gauge chip as well.
Be aware if you are designing a product that has to meet safety approvals, either the battery pack itself has to have a integrated monitoring circuit to ensure the input voltage is not exceeded, or you have to put one on you PCB circuit. Why? Because if the BQ chip (or any chip for that matter) decides to fail where it shorts input to output, and especially if the supply is high current, the battery can fail in a catastrophic way. Make sure the battery pack has been tested and complies to IEC 62133.