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DRV110: maximum oscillator frequency?

Stefan Lintner
Expert 4675 points
Part Number: DRV110

Hi team,

can you please specify how the maximum oscillator frequency on drv110 can be set.

There are different infos on the DS compared to this reference design

https://www.ti.com/lit/ug/tidu584a/tidu584a.pdf?ts=1712584124873&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTIDA-00284

(Look at 4.2.2.4)

The DS says maximum is 25 kHz -> 160kohm

The ref design says 67kHz -> ~60kohm

What is correct here?

BR,
Stefan

  • +1
    TI__Mastermind 21970 points

    Hey Stefan,

    Great catch on this discrepancy.

    In section 4 Revision History of the datasheet, from Revision B --> C the max externally set PWM clock frequency was changed from 60kHz to 25kHz.  

    I'm not able to find any further information behind this change.  There is likely a scenario where the higher frequency doesn't perform as expected on the device. 

    You're welcome to test it out yourself and see if smaller R_OSC like as shown in the reference design still results in a higher frequency for your operating conditions.  Just fair warning that device-to-device variation with different temperatures/voltages might result in the frequency not working for some devices.

    What load are you driving? We might have a device better suited for your application

    Best,

    Jacob 

  • 0 in reply to Jacob Thompson
    TI__Expert 4675 points

    HI Jacob,

    Their load is solenoid with nominal coil resistance 12 Ohms. Nominal voltage is 6 Volts. Starting current is about 600 mA and keeping open current is about 300mA.

     And also, they need 6 solenoid channels in their application.

    Would you recommend another device?

    BR,
    Stefan

  • +1 in reply to Stefan Lintner
    TI__Mastermind 21970 points

    Hey Stefan,

    Admittedly we don't appear to have anything perfect for this application. 

    One option is DRV8847 - it has independent 1/2 bridge control and current regulation, so you could use it to drive 4 of the 6 solenoids.  

    Another is DRV8906-Q1, though it only has PWM control not true current regulation.  One of that device would drive all 6 loads.

    Best,

    Jacob