IR2104 for DC motor control

[gehan_s]

Hi every one !!!!!!!!!

I want to use the IR2104 as a MOSFET gate driver for H bridge that controls a DC motor. However I want to do so using one PWM input and a GPIO pin of my PIC microcontroller. I went through the datasheet and came up with the below circuit. Can someone please look into it and tell me whether it will work or not (before I bread board it and burn my MOSFETs and drivers)?


Regards

 

[FvM]

The high side drivers will only work, when the respective low-side drivers are activated periodically. That's no the case with the intended PWM control scheme.

 

[gehan_s]

Thank you FvM for your reply !!!!!!!!!

I cannot change the fet drivers now as I've already bought them. Can you suggest a way to get this working ? BTW it's ok that I have to use both PWM pins as I just want to get this thing running.

Regards

 

[FvM]

A PWM scheme implementing synchronous switching is necessary. It would be also preferred due to lower losses.

I see three options:
1. standard 2-level (or bipolar) PWM.
Connect PWM to IRF2104 IN ports, one side inverted. Use SD to turn the driver off. Disadvantage: Higher ripple current.

2. standard 3-level (or unipolar) PWM.
Needs two phase shifted PWM signals, either generated by the controller or external logic

3. simplified unipolar PWM. Feed PWM signal to IN of one IRF2104 and connect the other IN to ground (low side permanently on). For direction reversal, flip the signals.