DRV110: DRV110 Rosc

Allen12

Part Number: DRV110

Hello, with Rosc = ~160k an audible hissing noise can be heard, replacing Rosc with a ~64k, the hissing noise is minimized.

With Rosc set to 64K, what are the ramifications? Does the Higher Osc frequency result in a fixed PWM?

thanks

over 1 year ago

0 David Medis over 1 year ago

TI__Genius 11030 points

Hi Allen,

When using the Rosc = 160k the pwm frequency is 25 kHz. This is above the audible range of 20 kHz so you should not be able to hear pwm signal. It is likely that the hissing is coming from another source. There are multiple free frequency apps such as Sonic Tools that will assist in determining the location and range of hissing noise.

Best,

David

0 Allen12 over 1 year ago in reply to David Medis

Intellectual 435 points

Hello David.

it's related to the DUT and is somewhat migrated by changing Rosc to 64K. What are the ramifications of selecting a Rosc below 160K?

this thread has a similar issue,

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1129352/drv110-osc-freq/4190366?tisearch=e2e-sitesearch&keymatch=DRV110%252520noise#4190366

it's unclear how it was resolved.

0 David Medis over 1 year ago in reply to Allen12

TI__Genius 11030 points

Hi Allen,

TI does not recommend operating devices outside of specified parameters as it can lead to damaging the device.

The fPWM may appear to be slower at the output (causing noise), if the VSENSE pin exceeds VREF to often.

Using ROSC = 160k, try changing RSENSE to keep VSENSE lower than VREF.

Best,

David

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DRV110: DRV110 Rosc