DRV11873: Recommendation to replace LB11685

Yoshikazu Kawasaki

Part Number: DRV11873
Other Parts Discussed in Thread: DRV10974

Hello,

My customer has been using LB11685AV(ON Semi), but it will be EOLed, so they have to find an alternative motor driver soon. If I checked cross reference, it gave me DRV11873. However if I understand correctly, DRV11873 isn't recommended because it has some issues which wouldn't be fixed due to resource issue. It was originally designed for a customer and has been released as a public IC later, so it's not recommended for a general purpose.

Questions

1. Would you please tell me which one you recommend for the replacement of LB11685? Do you still do DRV11873 for a customer who isn't familiar with it at all?

2. My customer has been using LB11685 because one of their customers doesn't like PWM output and insists on linear output because PWM has noise issue and LB11685 seems to have linear(PAM) output. Do you have 3 phase BLDC motor drivers with PAM output? Note that my customer needs FG output(nice to have), output current=1A(max) and Vs(max)=20V.

Best Regards,

Yoshikazu Kawasaki

over 2 years ago

0 Aaron Barrera over 2 years ago

TI__Mastermind 26046 points

Hi Kawasaki-san,

1. DRV10974 and DRV11873 are best solutions that support the motor specs with FG output.

2. We do not support pulse-amplitude modulation (PAM), only PWM inputs/outputs. Why does the customer have PWM noise issues? Is this from the PWM input side or output from the driver?

Thanks,
Aaron

0 Yoshikazu Kawasaki over 2 years ago in reply to Aaron Barrera

Intellectual 515 points

Hello Aaron-san,

Thank you for your quick reply. It seems LB11685AV with the PAM output doesn't have noise issue, so the end customer insists on PAM output. They say PWM output is the root cause of the noise issue they had in the past. Actually, they recently tried a motor driver IC with PWM output from one of our competitors, but it generated the noise issue, so they asked us again if TI really doesn't have PAM output.

Best Regards,

Yoshikazu Kawasaki

0 Vishnu Balaraj over 2 years ago in reply to Yoshikazu Kawasaki

TI__Mastermind 24405 points

Hi Yoshikazu-san,

Unfortunately, we do not have any Motor driver ICs that support PAM.

Regards,

Vishnu

0 Yoshikazu Kawasaki over 2 years ago in reply to Vishnu Balaraj

Intellectual 515 points

Hello Aaron-san, Vishnu-san,

I suppose the root cause of the noise would be their schematic and/or layout. Otherwise TI's motor drivers won't be used by many customers. Do you have application notes I should check for fixing the noise issue?

Best Regards,

Yoshikazu Kawasaki

0 Vishnu Balaraj over 1 year ago in reply to Yoshikazu Kawasaki

TI__Mastermind 24405 points

Hi Yoshikazu-san,

We can't comment anything without knowing much about the noise issue that customer is referring to. Note that DRV10974 can take analog voltage as speed input. This option can completely eliminate the PWM signal.

Regards,

Vishnu

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DRV11873: Recommendation to replace LB11685