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TPS2HB35-Q1: PWM Max frequency

LEANDRO SCHMITZ
Prodigy 220 points
Part Number: TPS2HB35-Q1

Hello,

I'd like to use TPS2HB35-Q1 to control a hydraulic proportional valve.

And I'd like to know how is the maximum frequency for PWM

My idea is to apply a 1KHz PWM and use internal current sense as the input of a PID to control the current and oil flow through the valve.

Thank you for help.

  • 0
    TI__Mastermind 23410 points

    Hi Leandro,

    The maximum frequency will depend on your load. I won't be able to give you the proper maximum frequency as I do not have that information.

    Unfortunately, some calculations show that you won't be able use a 1kHz frequency PWM with this device. 

    If you do need 1 kHz and can provide more information about your load, I can potentially give you a different 2CH device recommendation. 

  • 0 in reply to Anthony P Pham
    Prodigy 220 points

     The actual system work with 2 types of valves, one of 1.2A and other with 3A.

    It uses a discrete low side with 1KHz of PWM for 1.2A and a lower frequency for 3A valve.

    The current monitor is done with a shunt resistor and a current sense amplifier. 

    1- 1.2A Coil Valve

    2- 3A Coil Valve

    I'd like to do the current control with a high side, max current of 4A. 

    I appreciate your recommendation.

    Thank you

  • 0 in reply to LEANDRO SCHMITZ
    TI__Mastermind 23410 points

    Hi Leandro,

    Thanks for the information. If you have just one channel at 1kHz, this will do much better. You'll be able to work with the TPS2HB35-Q1 devices with your 3A valve at 90Hz with your 1.2A valve at 1kHz if you need the 4A limit

    Another device that could work is the TPS2HB16 if you're ok with a typical current limit of 4.1A. This'll bring your frequency on the 3A to 400Hz.

    These recommendations are based on calculations you can find in this app note and assumed an ambient temperature of 105C. If you have more information about your load conditions such as ambient temperature that the device will be operating in, I can adjust the calculations for you.