DRV8301 used to drive only 2 half bridges and without using the buck converter

Joel Soares

Other Parts Discussed in Thread: DRV8301

Hello, I am designing a board with several drv8301 and for one of them i only need to drive 2 half bridges.

What should I do with the unused pins ?

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For the pins of the buck :

I have only connected EN_BUCK to ground and the others (RT_CLK, COMP, VSENSE, SS_TR, PVDD2, BST_BK, PH)) are unconnected.

Is it correct ?

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For the pin of the unused half bridge :

I have pull down to ground INL_A and INH_A.

Is the capacitor between BST_A and SH_A still neccessary?

Can I put SH_A and SL_A to ground ?

Can I let GH_A, GL_A, unconnected ?

Best regards

over 12 years ago

0 Ryan Kehr over 12 years ago

TI__Guru 55605 points

Joel,

For the buck, if you have left it unpowered (PVDD2 unconnected), then it is not even necessary to connect EN_BUCK to ground. It won't hurt anything...just not necessary.

I need to get more clarification on the unused half-bridge connection. I will get back shortly.

0 Ryan Kehr over 12 years ago in reply to Ryan Kehr

TI__Guru 55605 points

Joel,

One question that I need answered to proceed:

What is your setting of the PWM_MODE bit? It is bit 3 in control register 1.

0 Joel Soares over 12 years ago in reply to Ryan Kehr

Intellectual 320 points

Hello Ryan,

In fact, I use the independant mode so the bit is zero.

0 Ryan Kehr over 12 years ago in reply to Joel Soares

TI__Guru 55605 points

Joel,

Recommendations are as follows for the unused half-bridge:

INL_A, INH_A : Pull to ground

SH_A, SL_A : Pull to ground

GH_A, GL_A : leave unconnected (GL_A will be pulled to GND internally and GH_A will be shorted to SH_A)

Bootstrap capacitor should NOT be installed on this channel.

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DRV8301 used to drive only 2 half bridges and without using the buck converter