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DRV2605L: Analog input/output

Takumi Suzuki1
Mastermind 8430 points
Part Number: DRV2605L
Other Parts Discussed in Thread: DRV2625

Hi,

Let me confirm you a following issue.

Q) DRV2605L has an analog input interface.

My understanding is that analog input signal is converted to PWM signal according to signal level.

So we can not output real sinwave via DRV2605L.

That is to say, sin wave input ----> DRV2605L ----> PWM output, not sin wave.

Is this correct?   

If yes, could you let me know the solution to drive LRA with sine wave?

Thank you in advance.

Best Regards,

  • 0
    Mastermind 8430 points
    Sorry one more question, please.
    About ERM mode, the output is also the same as LRA mode, correct? (PWM out, not sine wave)
    Thanks!
  • 0 in reply to Takumi Suzuki1
    TI__Expert 8721 points
    Hi Takumi-san,

    In closed-loop, the analog input interface is based on a reference voltage rage 0V-1.8V. The DRV2605L will track the resonance frequency of the LRA and always output a pseudo-square wave signal at the resonance frequency of the LRA. The analog input determines the driver strength or output magnitude from 0% (0V) to 100% (1.8V). 100% output is based on the RATED_VOLTAGE register.
    In open-loop, the frequency is set by the OL_LRA_PERIOD[6:0] register and the output will be a square-wave at that frequency. The output magnitude will also be determined as above, 0% (0V) to 100% (1.8V). 100% output is based on the OD_CLAMP register.
    No, you cannot output a pure sine wave based on the input sine wave. This would just be a basic amplifier..
    On the other hand, the DRV2625 can output sine-waves. The DRV2625 does not have an analog input interface.

    ERM mode is also as above. ERMs run on DC voltages, so the output is not a differential square-wave.. The output is a square wave on a single output (OUT+ or OUT-) where the duty cycle determines the magnitude. The other output is held at 0V except for when we track the BEMF voltage.
  • 0 in reply to Kelly Griffin
    Mastermind 8430 points
    Hi Kelly-san,

    Thank you so much for your kind reply!!

    Best Regards,