{"id":6656,"date":"2019-12-15T18:22:30","date_gmt":"2019-12-15T23:22:30","guid":{"rendered":"https:\/\/dronebotworkshop.com\/?p=6656"},"modified":"2023-04-11T19:07:10","modified_gmt":"2023-04-11T23:07:10","slug":"tb6612fng-h-bridge","status":"publish","type":"post","link":"https:\/\/dronebotworkshop.com\/tb6612fng-h-bridge\/","title":{"rendered":"TB6612FNG H-Bridge with Arduino – Better Than L298N?"},"content":{"rendered":"\n

\"Download \"Parts<\/a> \"View<\/a> \"Download<\/p>\n

Today we will look at another H-Bridge motor controller. This one uses MOSFETs and is a great replacement for the L298N.<\/span><\/p>\n

<\/div>\n

Follow along and learn how to use the TB6612FNG H-Bridge with your Arduino projects.<\/span><\/p>\n

Introduction<\/span><\/h2>\n

Controlling the speed and direction of DC motors is a very common application for both microcontrollers and microcomputers. You can probably think of many projects that you could build using these devices, from robots to cat toys.<\/span><\/p>\n

But if you\u2019ve ever tried connecting a DC motor directly to a microcontroller like an Arduino <\/span>you\u2019ll quickly find out that it isn\u2019t feasible. Not only will it not work, as the Arduino cannot provide enough current for the motor, but you will also probably find yourself in the market for a new Arduino very soon!<\/span><\/p>\n

\"TB6612FNG<\/p>\n

DC motors require more current than any microcontroller or microcomputer can directly provide, and many of them operate on different voltages that your processor can\u2019t deal with. So obviously some sort of interface is required.<\/span><\/p>\n

The most common method of controlling a DC motor is to use a device called an H-Bridge. This type of controller allows you to control both the speed and direction of a DC motor, and a pair of H-Bridges can also be used to control a bipolar stepper motor.<\/span><\/p>\n

We have used H-Bridges in many of our projects. They are relatively inexpensive and are pretty simple to work with.\u00a0 And the most common H-Bridge we\u2019ve used thus far is the L298N.<\/span><\/p>\n

The L298N is a very common component and it is used in hundreds, if not thousands, of Arduino designs. It\u2019s inexpensive and, once you understand how it works, is quite simple to use. But it does have its flaws, which I’ll go into in a minute.<\/span><\/p>\n

Today we will work with a better H-Bridge, one that can replace the L298N in many applications.\u00a0 It\u2019s called a TB6612FNG and after using it I think you\u2019ll agree that it is a much better choice than the old L298N.<\/span><\/p>\n

H-Bridge Recap<\/span><\/h2>\n

Before we get started, it might be a good idea to recap how an H-Bridge works, just in case it\u2019s still a mystery to you.<\/span><\/p>\n

The following diagrams came from the article <\/span>Controlling DC Motors with the L298N Dual H-Bridge and an Arduino<\/span><\/i> that I wrote a few years ago. If you want a more in-depth explanation of DC motor and H-Bridge operation I would urge you to check it out.<\/span><\/p>\n

You can visualize an H-Bridge as an arrangement of four switches. As you can see the switches are arranged in a pattern that looks a lot like the letter \u201cH\u201d. thus the name \u201dH-Bridge\u201d.<\/span><\/p>\n

\"H-Bridge<\/p>\n

The motor is placed in the middle of the \u201cH\u201d as illustrated in the diagrams.\u00a0 With the switches off the motor receives no current, as you would expect.<\/span><\/p>\n

\"H-Bridge<\/p>\n

If we close a couple of switches, as illustrated above, you can see that the current is allowed to flow through the motor, causing it to rotate clockwise. Obviously you don\u2019t want to close more than two switches at a time as doing so could cause a short circuit.<\/span><\/p>\n

\"H-Bridge<\/p>\n

Closing the other two switches also applies current to the motor, but in the opposite polarity. This causes the motor to spin counterclockwise.<\/span><\/p>\n

While you could construct an H-Bridge using physical switches it isn\u2019t done very often. In most cases, the switches are replaced with semiconductors, like bipolar junction transistors (BJTs) and MOSFETs.<\/span><\/p>\n

Replacing the switches with semiconductors has an additional advantage – it allows you to regulate the motor speed as well.<\/span><\/p>\n

Pulse Width Modulation (PWM)<\/span><\/h3>\n

Pulse Width Modulation, or PWM, is essentially what it sounds like. A pulse is sent to the transistors controlling the H-Bridge, which turns the electronic \u201cswitch\u201d off and on at a pretty rapid rate.<\/span><\/p>\n

The width of the pulse can be changed to set the ratio of \u201con\u201d versus \u201coff\u201d. This has the effect of controlling the speed of the motor.<\/span><\/p>\n

\"PWM<\/p>\n

PWM is a much better way of regulating the speed of a DC motor than just changing its supply voltage. With PWM the motor operates at full torque throughout the speed range, as opposed to the reduced torque you\u2019d experience at lower speeds using voltage control.<\/span><\/p>\n

TB66121FNG H-Bridge<\/span><\/h2>\n

Now let\u2019s look at our \u201cbetter\u201d H-Bridge module.<\/span><\/p>\n

The TB6612FNG H-Bridge is a small and inexpensive dual-channel H-Bridge controller that uses MOSFETs to achieve it\u2019s great performance.<\/span><\/p>\n

Made with MOSFETs<\/span><\/h3>\n

MOSFETs have an enormous advantage over bipolar junction transistors or BJTs.\u00a0<\/span><\/p>\n

A typical BJT has a voltage drop of approximately 0.7 volts when it is \u201con\u201d, and since an H-Bridge requires the current to pass through two BJTs the total voltage drop is 1.4 volts. At low voltages this can really make a difference, if you supply the H-Bridge with 6-volts then the output to the motor will only be 4.6-volts. In this example, almost 25% of the voltage is lost in the H-Bridge.<\/span><\/p>\n

The energy from that voltage needs to go somewhere, and it does – it is dissipated as heat. This is why most BJT-based H-Bridges require a big heatsink.<\/span><\/p>\n

With a MOSFET you don\u2019t have a fixed voltage drop. Instead, the MOSFET has a very small resistance when it is on, typically a fraction of an ohm.\u00a0 Even with two MOSFETs turned \u201con\u201d in an H-Bridge design the total resistance is very low, in fact, if you\u2019re using long thin-gauge wires for your power supply you may have more resistance in the wires than you do in the H-Bridge.<\/span><\/p>\n

The result is an extremely low, almost negligible, voltage drop. This means that nearly all the voltage from the power supply is delivered to the motor.\u00a0 And, with very little voltage drop to deal with, there is very little heat to dissipate.\u00a0<\/span><\/p>\n

If you\u2019d like to learn more about working with MOSFETs and Bipolar Junction Transistors please check out the article and video <\/span>Arduino High-Current Interfacing \u2013 Transistors & MOSFETs<\/span><\/i><\/a>.<\/span><\/p>\n

TB6612FNG Specifications<\/span><\/h3>\n

The TB6612FNG has the following specifications (the specs are for each of the two H-Bridges in the package):<\/span><\/p>\n