drv8832 half-bridge IC questions

[Vizier87]

Hi guys,
I recently acquired this sample from TI.

So according to the datasheet, regarding Vref and Vset:

Reference Output
The DRV8832 includes a reference voltage output that can be used to set the motor voltage. Typically for a constant-speed application, VSET is driven from VREF through a resistor divider to provide a voltage equal to 1/4 the desired motor drive voltage.
For example, if VREF is connected directly to VSET, the voltage will be regulated at 5.14 V. If the desired motor voltage is 3 V, VREF should be 0.75 V. This can be obtained with a voltage divider using 53 kΩ from VREF to VSET, and 75 kΩ from VSET to GND.

However, I have another idea, since using resistors will be a bit tedious with the board I'm fabricating being small and whatnot, I'd like to achieve a 3.3V regulation by connecting 3.3V to Vref and GND to Vset. That will also set it to 3.3V, isn't it?

Thanks for any input here.
Vizier87.

 

[alec_t]

I'd like to achieve a 3.3V regulation by connecting 3.3V to Vref and GND to Vset. That will also set it to 3.3V, isn't it?

No it won't. Vref is an output. If you try driving it from an external source you will probably destroy the chip.

 

[Vizier87]

aaah thanks. I wasn't thinking properly on this one. So are there any alternatives without using resistor networks?

 

[alec_t]

You could apply 0.825V directly to VSET.