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DRV8889-Q1: DRV8889-Q1

Munesh Tripathi
Prodigy 140 points
Part Number: DRV8889-Q1

Hi,

I am trying to drive stepper motor by DRV8889-Q1 IC. I have few queries over that please clear.

1. Sleep pin status have to be defined (pulled high) for its working or it can be in float

2. For VREF, Vcc can be provide by external (in board) source or it has to be drive by DVDD only.

3. 479nF 10V capacitor recommended at DVDD. Can I use higher voltage capacitor with same farad rating. And it is little bit far from my IC (around 10mm), is that OK ?

4. Do I really need a bulk capacitor if I am driving my load with external DC regulated power supply. If yes then at which pin 1 or 8.

5. In technical datasheet a cap recommended at VSDO pin .1uF but in same datasheet when I went to PCB layout it shows .01uF cap. Is it really matter for driving load ?

  • 0
    TI__Mastermind 44135 points

    Hi Munesh,

    Thanks for contacting via this forum and thanks for your interest with the DRV8889-Q1. My answers below in the same order as your questions.

    1. nSLEEP pin has an internal pull-down of 200kΩ, see Figure 7-16 of the datasheet. Sleep pin must be pulled high using a controller or can be permanently tied logic high externally. It cannot be floating or cannot be tied to DVDD, else the device will never exit sleep mode.

    2. VREF can be provided by external source with reference to GND. You can download EVM schematic where VREF is provided by the external MCU.

    3. 470nF 10V is recommended because capacitances are specified at operating voltage. As long as the capacitance value is met with no issues with using a slightly higher voltage rating. The closest possible to the IC is better. 10cm is not too bad.

    4. Whichever pin gets the first connection from the supply voltage. If the leads from the power supply is short enough and the power supply has large enough capacitors at its output the bulk capacitor can be reduced to 47uF or so. See datasheet page-67 section 9.1.

    5. Use a 0.1uF for VSDO.

    Regards, Murugavel