Liion or Lipol charge IC - function without battery?

[darksir]

Hi boys,
I need Liion backup for my GSM module apllication.
I have 12V supply, which is regulated to 4V. I found MCP73871 for Liion charging.

When I remake circuit and use this IC as power IC, with Liion backup, will be power supply enough for GSM module when I use this without Liion? Liion will be used optionally and I need one circuit for backup and nobackup circuits...

Thank you, Petr

 

[mister_rf]

With the SEL input High, the MCP73871 device is designed to provide a typical 1.65A to system power and charge Li-Ion battery from a regular 5V wall adapter. The MCP73871 device limits the input current up to 1.8A.

https://www.adafruit.com/datasheets/MCP73871.pdf

1.65 Amps it’s enough for?

 

[darksir]

Many thanks. This is good IC, but have a bad package. QFN is difficult to solder. I foud any application note from microchip where was cheap Liion charger with external Mosfet and diode. This mosfet switch load to power supply, or lioon when power supply down. Is it good idea? Thi is cheap, variable and only 3 parts are needed. Charge controller, mosfet and diode + resistor - OK.

 

[mister_rf]

Let’s see the application note.

Soldering a QFN Package by hand: :-D
https://store.curiousinventor.com/guides/Surface_Mount_Soldering/QFN