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DRV8873SEVM: Changing the switching frequency of the DRV8873 Eval. Board

Katrin Ippisch
Prodigy 20 points
Part Number: DRV8873SEVM
Other Parts Discussed in Thread: DRV8873, MSP430G2553

Dear Sir or Madame,

I have an Evalboard with the modulse DRV8873. One Module should drive two Peltier Chips with 4 A and 24V of a TEC.

The Polarity reversal works very well if we put an coil in the circuit.

To reduce the size of the coil we wanted to increase the switching frequency up to 100 KHz.

The DRV8873 ist driven by SPI with the MCU MSP430G2553.

The biggest problem now is that unfortunatly i can't find any further informations, with which frequency the module is currently being driven. And i can not find and informations where i can switch de Frequency.

The GUI for the EVM is already installed. Are there any special registers where i can change the switching frequency? Where can i find this information?

or can we only use the PH / IN2 and EN / IN1 interfaces to inject the switching frequency of 100 kHz?


Thanks for your effort

Yours sincerely

Katrin Ippisch

  • 0
    TI__Guru** 114905 points

    Hi Katrin,

    The PWM frequency is set by the mcu. The mcu provides signals to the PH/IN1 and EN/IN2 inputs.

    To increase the PWM frequency, there are a few options.

    1) Modify the mcu code. We do not provide guidance for modifying the code. Please be aware the GUI may not work after the modifications.

    2) Remove the series resistors between the mcu and the PH/IN1 and EN/IN2 inputs. You can then control the GUI to configure the device and use a pulse generator to drive the PH/IN1 and EN/IN2 inputs.

    3) Remove all the series resistors between the mcu and the DRV8873. This will allow an external mcu to connect to the DRV8873 to control the device.