DRV8825 SMD circuit not working

Suyog Vyawahare

Other Parts Discussed in Thread: DRV8825

We have created DRV8825 driver pcb using through hole components and its working properly (With some issues mentioned over here https://e2e.ti.com/support/applications/motor_drivers/f/38/t/421282 )

Now we have created same pcb with SMD components and addition of voltage divider resistors for Vref.

This circuit is not working, I am not getting 3.3V across V3P3OUT pin and after disconnecting voltage divider resistors from Vref pins, i am getting 3.3V at vref pins

w.r.t ground. and across CP1 and CP2 i am getting 24V w.r.t ground.

I am attaching both pcb layouts

Following is not working

Following is working

Can anyone tell me where i am going wrong?

over 10 years ago

0 Wilson Zuo over 10 years ago

TI__Mastermind 26065 points

We will check this and get back later.

Best regards,

0 Wilson Zuo over 10 years ago in reply to Wilson Zuo

TI__Mastermind 26065 points

Hi Suyog,

In your layout of the "not working one" the nSLEEP is connected to V3P3OUT. This is not allowed because nSLEEP will disable the V3P3OUT, so the device is latched in SLEEP state after power on.

I'm not sure of your description about "I am not getting 3.3V across V3P3OUT pin and after disconnecting voltage divider resistors from Vref pins". Anyway you need control the nSLEEP logic input by external logic voltage.

Best regards,

0 Suyog Vyawahare over 10 years ago in reply to Wilson Zuo

Intellectual 965 points

Can I connect nSleep pin with nEnable and control it or they need to be separated?

Sorry stupid question!

0 Suyog Vyawahare over 10 years ago in reply to Wilson Zuo

Intellectual 965 points

Hi
I connected external 3.3V to nSLEEP now nSLEEP, nRESET and V3P3OUT are externally pulled up to 3.3V still its not working! Vref is 1.44V and Rsense is 0.15ohm no load is connected to motor

Motor drivers

Motor drivers forum

DRV8825 SMD circuit not working