Is it safe to go above the recommended capacitance value for motor driver?

Using Arduino General Electronics
1

I am connecting a TB6612 motor driver to 2 DC motors rated at 6 V each and using Arduino UNO. I pulled up the motor driver datasheet and the recommended value of capacitance stated is 10 μF to 33 μF electrolytic between VCC and GND to suppress noise.

I have 3 questions:

  1. Is it safe to go above the maximum recommended value of 33 uF? (i do not have any capacitors in the recommended range).
  2. How high can i go with the capacitance value?
  3. What capacitor voltage rating should i use?
2

If you are using a motor driver module and not the naked chip, those caps should already be there.

The TB6612 data sheet I have recommends 0.1 uF and 10 uF in parallel, on each of the power leads, Vcc and VM1 (motor power). There is probably no advantage in going higher than 33 uF for the larger of the pair. The caps must be rated for higher than the input voltages.

3

It's in the Application Note: TB6612FNG | Brushed DC Motor Driver ICs l Multi-Channel Motor Drivers | Toshiba Electronic Devices & Storage Corporation | Americas – United States

Download link: https://toshiba.semicon-storage.com/info/docget.jsp?did=54655&prodName=TB6612FNG

This is the section on page 7:

tb6612caps.png
tb6612caps.png691×348 50.3 KB

I'm using this module: Pololu - TB6612FNG Dual Motor Driver Carrier

But in online schematics, i've noticed that they added decoupling capacitors, so i'm trying to figure out what values to use, as i assume it's for additional smoothing of the DC voltage.

Also, what capacitor should i use for the input voltage to Vin on the Arduino? I'm using a 12 V DC battery.

tb6612caps.png
tb6612caps.png691×348 50.3 KB

4

The Pololu engineers are among the very best in the business. They study and follow the instructions in the device data sheets very carefully. Furthermore they extensively test every module before it goes out the door.

So, there is no need to add any capacitors, unless the engineers specifically recommend it (and they don't in this case; in other cases they do, on the leads coming from the motor power supply).

Also, what capacitor should i use for the input voltage to Vin on the Arduino?

You don't need one. Use lower than 12V (e.g. 7-9V) if possible, or the Arduino on board voltage regulator may overheat.

5

We once ran into a issue by having too large of a capacitor, but that was a fast switching circuit which “needed” the recharge slope to complete in time.

Dropping down to the correct size allowed the voltage to recover faster.