Hi , i don't see how u can control current with pwm frequency !! , i don't think it's possible .
Pwm, basically, controls Voltage, and as u mentioned, it's the duty cycle who affects the output voltage .
Besides that, u sould consider using a filter as an output stage to obtain a stable output voltage . ( an RC filter for example ) .
i can't help you with current control , i hope folks here will tell u more about it .
I am referring to a Buck Converter Battery Charger for Li Ion, how can I control the constant current charge and then constant voltage charge using PWM? Thank you.