Using a TB6612FNG breakout circuit

Other Hardware 3rd Party Boards
1

Hello,

I'm trying to build a small toy that uses two DC motors. It grew from a very simple idea to an excuse to use an Atmega328. I'm using an Arduino Uno for programming, but I already got an additional microchip for the standalone version.

First time for me, but I think I have an idea of the basic components I need to run a standalone Atmega328 (reset pullup resistor, decoupling capacitors, crystal). I've found less information on the TB6612FNG breakout circuit however.

Some specific questions about the TB6612FNG breakout circuit :

  • Does it need decoupling capacitors between VCC and GND?
  • How about VM and GND?
  • Do I need diodes between the TB6612FNG output and the motors? In the Arduino project book, the circuit with the L239D does not use any diode. Is it the same with the TB6612FNG.
  • Also, is there any way for the Atmega328 to perhaps cut the power to the TB6612FNG right before going to sleep mode? I think that switching STBY will cut the motor power, but the chip will still be working right? I suppose I cannot power the TB6612FNG off an Atmega328 output pin. (I've found no specs for the amperage of the breakout circuit).

Thank you for reading!
Eloy

2

Yes. See application circuit in datasheet. They show 0.1uf and a larger cap on both Vcc and VM - note that your breakout board will at least include the 0.1uf caps on it if you get a commercial TB6612 breakout board.
Yes, as noted above.
Nope, it's got internal ones, per datasheet.
Drive STBY low before going into sleep, per datasheet consumption should be 1uA while STBY is low.

3

DrAzzy:
Yes. See application circuit in datasheet. They show 0.1uf and a larger cap on both Vcc and VM - note that your breakout board will at least include the 0.1uf caps on it if you get a commercial TB6612 breakout board.
Yes, as noted above.
Nope, it's got internal ones, per datasheet.
Drive STBY low before going into sleep, per datasheet consumption should be 1uA while STBY is low.

Thank you for the response!

It's a commercial one, yes, this is the layout (it's a cheap one with no documentation :S): https://images-na.ssl-images-amazon.com/images/I/41XE0GcMa3L.jpg (https://www.amazon.co.uk/TB6612FNG-Motor-Driver-Module-Arduino/dp/B017347VXO)

Comparing with the Pololu product (Pololu - TB6612FNG Dual Motor Driver Carrier), I think the one I bought has C1, C2 and C3. The datasheet typical application schema (https://www.pololu.com/file/0J86/TB6612FNG.pdf, page 7) does not include Pololu's C4 (a 3rd capacitor at VM), but has two capacitors for VCC as you mention.

Seeing the sizes of the components in the picture of the circuit I bought, I'm guessing that only the 10uF at VCC is missing.

One question: I was thinking of using one 0.1uF capacitor for each of the voltage input in the Atmega328 (VCC/GND and AVCC/GND). Does the TB6612FNG require more capacitors at VCC?