LM629 PIN 13(PWM MAG) AND PIN 11(PWM SIGN) Issues

Mickey Zhang

Genius 12080 points

Hi Team,

The customer is using LM629M-6.

PIN 13(PWM MAG) can output PWM and PIN 11(PWM SIGN) is a low level occasionally when the board is power on without any initialization. The PWM for PIN 13(PWM MAG) is about 3%. The malfunction has appeared on several boards. Once this malfunction occurs, the motor rotates fast.

The attached are the schematic and the waveform for the malfunction. VCC is 5V and fCLK is 6MHZ.

What is the reason? How to solve the issue?

Thanks,

Best Regards,

over 8 years ago

0 Rick Duncan over 8 years ago

TI__Guru** 114905 points

Hi Mickey,

Our experts have been contacted and should reply soon.

0 Mickey Zhang over 8 years ago in reply to Rick Duncan

TI__Genius 12080 points

Hi Rick,
Thank you. I am waiting for you reply.

0 Michael_DeSando over 8 years ago in reply to Mickey Zhang

TI__Genius 12630 points

Hello Mickey,

I have began to look into your issue and would like more information. You mention that there is a malfunction but what exactly is the problem? The PWM MAG is about 3% but what did you expect it to be? You also mention this malfunction occurred without initialization? It is important for the device to be initialized properly before operation. Please describe what you are intending to do to with this device so we can determine how to correctly accomplish that. Thank you!

0 Mickey Zhang over 8 years ago in reply to Michael_DeSando

TI__Genius 12080 points

Hi Michael,
Thank you for your reply. I will query the customer.

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LM629 PIN 13(PWM MAG) AND PIN 11(PWM SIGN) Issues