Li Ion charging using LTC4002-8.4V

I have used the schematic as given in the attachment

The part numbers we have chosen is given in the schematic and the datasheets are also attached.

We would like to use charge current on 1.5A to 2A (being Max). We shall change R6 in the schematic accordingly.

The battery vendor has said that their batteries have a internal cutoff at 8.3V but since LTC 4002 has a fixed 8.4. Can I change it to 8.2?? I dint find that in datasheet

I have also attached the placement file for the board.

I have had issues with MOSFET heating in earlier designs.

I need a little experience advice if I am doing it the right way. Choosing the right parts and using the right heat sink area. Its just not possible to increase the area for heatsink as there is hardly any space to do so.

We have a constraint of max height on 4mm so we had to choose the given inductor

Schematic




Board Placement






Datasheets Links

MOSFET

http://www.mouser.com/ds/2/308/NTHS5441T1-D-99521.pdf


INDUCTOR

http://www.mouser.com/ds/2/445/74437336068-516463.pdf


DIODE

http://www.mouser.com/ds/2/115/ds30924-33371.pdf


LTC4002-8.4V

http://cds.linear.com/docs/en/datasheet/4002f.pdf

Hi,

VBat of LT4002 can´t be changed. It is fix.

External "modifcation" of VBat signal (like adding 0.1V) is difficult, because it is also the sense input current control.

Klaus

KlausST... Let me talk to the battery manufacturer and see what can be done on this...

I am more concerned on the section of MOSFET and Inductor...

Last design, I used the MOSFET that used to heat a lot when the battery was completely drained and in some cases even blew up. I am doing this as a replacement for that old design.

Li Ion charging has CC and CV and that obviously effect the operation and dessipation on these components, hence was considering some suggestions from more experienced guys and I am sure there are a plenty in here who can help or give some advice