Author Topic: H-Bridge Braking (IFX9201SG)  (Read 1403 times)

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Offline normalverbraucherTopic starter

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H-Bridge Braking (IFX9201SG)
« on: May 07, 2019, 02:54:40 pm »
Hi,

I have been playing around with the Infineon IFX9201 Integrated H-Bridge lately, and I was unable to figure out how to brake a DC motor with this IC. There is no brake functionality specified in the datasheet (see attached pic).
Does anyone know of an easy way to quickly stop a DC-motor with this chip?
 

Offline soldar

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Re: H-Bridge Braking (IFX9201SG)
« Reply #1 on: May 07, 2019, 03:18:32 pm »
Reverse?
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 

Offline Etesla

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Re: H-Bridge Braking (IFX9201SG)
« Reply #2 on: May 07, 2019, 03:52:09 pm »
I think it depends on the direction the motor was already spinning.

Say you had HS1 and LS2 on, and then you wanted to break the motor. To break, you would turn off HS2 and LS2, and turn on just LS1. This would provide a reverse current path through LS1, through the diode in LS2, and through the motor, in the opposite direction breaking it.
The other case would be having HS2 and LS1 on to start, and then to break, turning off HS2 and LS1, and turning on just LS2.

I think turning on LS1 and LS2 at the same time for breaking would also work for both starting cases, even though one of the mosfets still shouldn't actually be conducting a whole lot during that time, but this simplification may be worth it.

I have never tried this, but this link makes me thing that this may work:
https://electronics.stackexchange.com/questions/56186/how-can-i-implement-regenerative-braking-of-a-dc-motor
 

Offline Benta

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Re: H-Bridge Braking (IFX9201SG)
« Reply #3 on: May 07, 2019, 04:25:36 pm »
What the data sheet calls "Free Wheeling" is actually braking.
 

Offline pwlps

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Re: H-Bridge Braking (IFX9201SG)
« Reply #4 on: May 08, 2019, 07:10:53 pm »
I have never tried this, but this link makes me thing that this may work:
https://electronics.stackexchange.com/questions/56186/how-can-i-implement-regenerative-braking-of-a-dc-motor

Yes, this article explains it very nicely. So to enable breaking the PWM should switch very fast between "forward" and "free wheel forward" (and this is what we see in the driver truth table).  If the PWM frequency is high enough (relative to the L/R time constant of the motor) then on  decreasing the PWM duty cycle the motor will act as a buck–boost converter, supplying current to the PS (this is regenerative braking - check if the PS can accept reverse current).  So in principle there is nothing special to do, progressively decreasing the PWM duty cycle will enable breaking.
This won't work anymore when the motor EMF drops below the diode threshold, but then you can probably safely switch to reverse.
 

Offline MarkF

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Re: H-Bridge Braking (IFX9201SG)
« Reply #5 on: May 09, 2019, 12:44:15 am »
I think it depends on the direction the motor was already spinning.

Say you had HS1 and LS2 on, and then you wanted to break the motor. To break, you would turn off HS2 and LS2, and turn on just LS1. This would provide a reverse current path through LS1, through the diode in LS2, and through the motor, in the opposite direction breaking it.
The other case would be having HS2 and LS1 on to start, and then to break, turning off HS2 and LS1, and turning on just LS2.

I think turning on LS1 and LS2 at the same time for breaking would also work for both starting cases, even though one of the mosfets still shouldn't actually be conducting a whole lot during that time, but this simplification may be worth it.

None of this is possible.  Look at the truth table the OP posted.
« Last Edit: May 09, 2019, 12:46:51 am by MarkF »
 

Offline Jwillis

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Re: H-Bridge Braking (IFX9201SG)
« Reply #6 on: May 09, 2019, 06:04:02 am »
There are three types of DC electric motor braking. 1 Plugging or reverse current braking. 2 Dynamic Braking or Rheostatic braking .3 Regenerative Braking or  kinetic energy of the motor is returned back to the power supply.
 


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