Battery Charging - Help?

Hi,
I want to make a battery charger LiIon with a micro controller.
I study about Li-Ion battery, charging methods and ...
LiIon should be charge with Constant Current/Constant Voltage method.
So we should be able to control current and voltage of charger.
So I use PWM for controlling these signals.
PWM On/Off Fets for charging with determined current and voltage
and with ADC we measured the voltage and current.
After reading the current and voltage, the duty cycle must be changed
if needed(change with PWM).
Now I want know, Should be stop the PWM when I want to measure voltage
and current?If yes, why? or if no, why?
please help me.

Why not use a battery charger IC? Or copy the circuit of a battery charger IC?

I'm using ATMEGA406 from ATMEL.
This micro controller is one of the battery management family with
battery charging and monitoring features.
ADC
CCADC
Battery protection
FET control
CELL balancing
and ...

I just to know when measurement of voltage or current,the pwm should be stopped?

Thanks

The chip is $4.50 @ Digikey
https://focus.ti.com/lit/ds/symlink/bq2954.pdf

My friend, My project is based on ATMEGA406.
I dont want use any other chips because ATMEGA406 is very good uC for
battery management.
Just please ask my question.
Thank you

hne573 said:

I'm using ATMEGA406 from ATMEL.
This micro controller is one of the battery management family with
battery charging and monitoring features.
ADC
CCADC
Battery protection
FET control
CELL balancing
and ...

I just to know when measurement of voltage or current,the pwm should be stopped?

Thanks

Click to expand...

if you want terminate fast charge with control voltage you mut stop sendig charge to battery and after that masure battery voltage if u use PWM for switch current or voltage to battery ya y but stop or sample voltage when its off