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ADS7953: Read PWM signals at input channels

Mayank Bhandari
Prodigy 120 points
Part Number: ADS7953

Hi

When I went through the datasheet and application note, I found the bypass capacitors have been placed in the channel input lines.

If so is the case, then can ADS7953 read PWM signals (modulated at 200 Hz with variable duty cycle)?

Won't a pwm signal be filtered by low pass filtering due to the capacitors? If yes, can ADS7953 be used for reading PWM signals without the filters?

  • 0
    TI__Mastermind 25020 points
    Hello,
    The ADS7953 should not be used to measure PWM signals, SAR ADC devices are not made to measure these types of input signals.

    If you can share the system with me, or the goal I could better help guide what type of device is adequate

    Regards
    Cynthia
  • 0 in reply to Cynthia
    Prodigy 120 points

    Hi Cynthia

    Thanks for replying.

    My usecase is that I am using a PWM signal to control the brightness of a traffic light (LED). Now I want to know whether the light has been working or not and to do that I am using INA240A1. Now, since it is a PWM signal the output of INA240A1 is also modulated. Moreover, I am out of my controller ADC pins. Therefore, I need an external ADC that can read the PWM signal output of INA240A1 and then communicate the output with my controller via SPI,I2C or UART. The external ADC should have atleast 12 channels. The operating voltage can be 3V3 to 15V.

    I hope this gives you a clearer picture and you shall be able to suggest the right IC to me.

    Thanks and Regards

    Cynthia

  • 0 in reply to Mayank Bhandari
    TI__Mastermind 25020 points
    This thread has been addressed on a separate post.

    e2e.ti.com/.../794150