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UC3637: uc3637 for motor control

Part Number: UC3637

We use UC3637 to generate PWM for IGBT control. Follow the spec and designed our schematic. the voltages and input signals are normal. but the output result is not well, the schematic have some problem, the PWM bring some harmonic voltage to output. who can help me?schemtic.docx

  • Hi Pan pan50,

    In your schematic, +BIN should be connected to -AIN, right now you have -BIN connected which should have the supplied voltage connected.

    Luis Riveros
    Motor Applications Team

  • In reply to Luis Riveros:

    Hi Luis,
    Thank you for your kind and rapid reply. we use send a couple of complementary signal to +BIN, -BIN and +AIN, -AIN, these singals to compare with the trianguler wave and use the generated PWM wave to control motor. in actully, the input singal is sine ware from our DSP. It's not the same as the examples. Do you still think we should change our design to the example? how about your ideas?
  • In reply to pan pan50:

    Hi Pan Pan50,

    Pins  8 and 10 should be connected together and back to pin 2. Maybe this app note can help. What is your end application? What is your motor spec? Could you use a microcontroller like the MSP430 to send PWM signals? what are you using as the motor driver? We might have a better solution if you let us know the specs. Thanks.

    Luis Riveros
    Motor Applications Team

  • In reply to Luis Riveros:

    Hi Luis,
    Thank you for your help!our product is similar as audio power amplifier, a new toy we design for child. Our destination is to transfer any possible input signals to the load without distortion. we think the artificial circuit is more efficiency than the microcontroller. Why we choice UC3637 is that this chip can generate two independent signals and we can divide two PWM signals to four, which is comfortable to driver H bridge.
    I think some small audio amlifier do the same design as us, the difference is the load. Do you have any experence to share with us? Do your have more resonable chip to recommend?

    my best wishes,

    Pan