DRV2511-Q1: LPF for IN+/IN-

Masatoshi Oguri

Part Number: DRV2511-Q1

Hi,

In FIGURE10. Typical Application Schematic of the datasheet, there are LPF to IN+ and IN- pins. Is there any concern of degradation of performance or damage to the device when there is no LPF? If there is any specific reason to put LPF, please make a recommendation for LPF design.

Thank you.

Regards,

Oguri (TIJ automotive FAE)

over 4 years ago

0 Luis Fernando Rodriguez S. over 4 years ago

TI__Guru* 84915 points

Hi, Oguri-san,

This LPF is recommended when the device input is a PWM signal. The low-pass filter will be used to remove the switching frequency content. In case the filter is not included, this switching frequency will be also amplified by the DRV2511-Q1.

Basically, we just recommend to add a low pass filter with a cutoff frequency of 22 - 30 KHz in order to remove this switching content.

Best regards,
Luis Fernando Rodríguez S.

0 Masatoshi Oguri over 4 years ago in reply to Luis Fernando Rodriguez S.

TI__Expert 4780 points

Hi Luis,

Thank you for the answer.

Do you recommend 2nd order LPF as on the EVM? Do you think 1st order filter is not enough?

Regards,

Oguri

0 Luis Fernando Rodriguez S. over 4 years ago in reply to Masatoshi Oguri

TI__Guru* 84915 points

Hi, Oguri-san,

The 1st order filter should be enough. The 2nd order was placed on the EVM in order to have a faster attenuation ramp. But the 1st order filter will have good results to filter the high frequency content.

Best regards,
Luis Fernando Rodríguez S.

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