Using PWM to control current

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ahmad_imran

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Hi,

I want to control current of 12Amp by using a PWM from microcontroller that is the output in voltage of 5V and the current is very low. Can anybody guide me how to do it? Or is there any links that I can refer to? Thanks.
 

1. the core of switching section can be a simple bulk regulator and the feedback from output current can be read using a low ohm/ high power resistor with one pin grounded, maybe a simple RC low pass filter is necessary to reduce swiching noise in measured current!
2. for driving a high side switch for the bulk regulator u need a bootstrap driver, many of manufacturers provide them like IR, Intersil...
3. the feedback loop is to fix output current, thus read and compare it with your reference using Error amplifier/ compensation (refer to pressman book or even app. notes from unitrode/TI about baatery chargers!). the reference can be SET using a sharp low pass filter at the output of the PWM pin of uC...

Hope this can be useful!

BEST!
 

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