Rustic Engineering

My Mind working on…

GUI v1 – part 2

with 4 comments

Continue from part 1…

About the H-Bridge and motors.

There’s a lot of H-Bridge CI’s on market today. The most used on DIY robots are:

My experiency with SN754410 is good. It’s a good device, friendy DIP package (don’t say the same about L298). But (always there’s a “but…”) it’s have a great voltage drop across the internal transistors. If you put 6V at Vmotor and a 1A load, you get Vmotor – 2V, so only 4V to the motors. For my robot I want a more efficient H-Bridge. L298 and L293D are bigger devices, have the same problem than SN754410 and… I hate L298 package. So, I move to a new device.

Fortunately, at same time I find the Toshiba’s TB6612FNG dual motor driver. It’s a really nice device, with a good package (SSOP24 300MIL). TB6612FNG specifications:

  • Motor voltage (VMOT): 4.5 – 13.5 V
  • Logic voltage (VCC): 2.7 – 5.5 V
  • Output current maximum: 3 A per channel
  • Output current continuous: 1 A per channel (can be paralleled to deliver 2 A continuous)
  • Maximum PWM frequency: 100 kHz

Pololu have it in a nice breakout board, very friendly (above). After some test, they are chosen for GUI v1.

H-Bridge

TB6612FNG H-Bridge

Written by forrequi

September 7, 2009 at 23:57

4 Responses

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  1. Hi rustic, i’m use L298 for my 5 phase motor stepper, you say that l298 has a lot of voltage drop…but it not happen to me.

    I put DC 10V at input, i get 10V too in the out, ofcourse with motor stepper as load.

    http://www.nastelroy.wordpress.com

    nastelroy

    October 3, 2009 at 12:24

    • According to datasheet, with a 1A load, it’s output high voltage loss is max 1.7V and it’s output low voltage loss is max 1.6V. It’s max total voltage loss is 3.2V.

      But with 2A load, it’s output high voltage loss is max 2.7V and it’s output low voltage loss is max 2.3V. It’s max total voltage loss is 4.9V

      Because the L298 is “transistor based“, it’s was very current (Ic) dependent. Try to measure a voltage current graph in your circuit.

      forrequi

      October 3, 2009 at 13:07

  2. Wher do you buy TB6612FNG? Because i cant find it anywhere

    exapod

    October 31, 2011 at 08:35

    • I hope I’m bought the last from Mouser.com. I cannot find it anymore too.
      Maybe you can move to LB1836M (if your project is small).

      forrequi

      October 31, 2011 at 09:51


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