[LOGO SOUND] Brushless DC motors can offer many performance benefits over brushed DC motors. BLDC motors are more efficient, offer higher power, higher torque, and have longer lifetime compared to their brushed DC counterparts. However, implementing BLDC motor control remains a large barrier to entry for many designers. 

In order to rotate a DC motor, a magnetic field must be applied using the stator coils. The stator coils can either attract or repel the permanent magnets found in the rotor. The interaction between the stator coils and the rotor is dependent on the polarity of the magnetic field generated by the stator coils. The polarity of these electromagnets can be controlled by the direction of current in the coils. 

Motor commutation is a process in which current is directed through the phases of the DC motor to generate motion. The video shows a simplified model of a BLDC motor which uses two magnet poles and three stator coils. The motion is caused by the attraction of the electromagnet to the opposite polarity of the permanent magnet and the repulsion between the electromagnet and the permanent magnet with the same polarity. 

Brushed DC motors have mechanical commutation which is achieved via the use of the commutator and the brushes inside the motor. The commutator spins with the rotor, so as the motor spins, the brushes make and break contact with the commutator ring, changing the direction of the current inside the motor to keep it spinning. 

These mechanical components make spinning a brushed DC motor relatively easy. Users simply need to apply a voltage to the motor and the mechanical parts inside the motor will handle the commutation for the user. These commutator and brushes are not found in the BLDC motors. While these mechanical components simplify the use of motors, they are major contributors to some of the performance pitfalls of BDC motors. 

Without these components to mechanically commutator the motor, commutation must be done electrically via the use of an external controller. This presents one of the major challenges of using BLDC motors. Without a physical commutator, the system's controller is in charge of manually changing the direction of current in each phase in the correct sequence relative to the rotor's position in order to keep the motor spinning. 

The main question is, how does the system know when to attract or repel the rotor to keep the motor in motion? There are several methods for identifying the rotor's position, but Hall effect sensors provide a relatively simple, affordable, and robust way of obtaining positional data. For a sensor trapezoidal control scheme, three Hall effect latch sensors are used to provide positional feedback by keeping track of the permanent magnet's polarity relative to the electromagnets. 

Each sensor output is out of phase electrically by 120 degrees. This phase difference allows us to create six distinct states with our three Hall effect latches creating one electrical cycle. This allows users to easily map out and generate a lookup table based on the Hall sensor state that indicates how the coils need to be energized in each state in order to keep the permanent magnets in motion. 

The number of poles in the motor dictate how many times the electrical cycle must be repeated in order to get one full mechanical rotation from the rotor. Texas Instruments' magnetic sensing portfolio provides many options when designing a board for BLDC motor commutation. The DRB5013 is a small form factor Hall effect latch capable of a bandwidth of kilohertz. This device enables mechanical flexibility by providing a SOT-23 and TO-92 package to accommodate various mechanical implementations, all while supporting a wide operating supply voltage from 2.5v to 38v. 

The DRB5011 is another small form factor Hall effect latch that also boasts a bandwidth of 30 kilohertz. This device enables compact designs by providing a push pull output that does not require an external pull up resistor while operating from a low 2.5v supply. 

The TMAG5115 delivers low output delay and low jitter for increased switching precision, all while providing a high bandwidth of 60 kilohertz. The device also features a short circuit protection as well as overtemperature protection and can operate using a wide supply range of 2.5v to 26v. The TMAG5115EVM is designed with a 120 degree offset between all devices needed in order to create the six unique steps for trapezoidal commutation. 

This form factor is compatible with various NEMA17 BLDC motors which means that we can use the EVM as a direct drop in replacement for the existing sensor boards in order to evaluate the device performance in an actual motor. In this video, we will be replacing the sensor board on an Anaheim automation BULY174S2-24V-12000 BLDC motor with a TMAG5115EVM to spin a motor. 

To drive the motor, we will be using a Texas Instruments MCT8316ZTEVM which features the MCT8316Z BLDC motor driver. The MCT8316Z features an internal sensor trapezoidal control for a fixed function state machine. This means that the device only requires the three Hall effect sensor signals without an external microcontroller in order to spin the motor. 

Let's get started. We start off by replacing the sensor board on the motor. First, remove the four screws on the bottom of the BLY174S motor. This allows us to take the motor apart. The main area we are looking at is the back plate opposite to the rotor where the connections are coming from. This portion of the motor assembly contains the Hall sensor board we are going to replace. 

The sensor board is then attached to the back plate by three screws. Removing these screws will allow the PCB to come loose. Once loose, we can remove the current board and replace it with a TMAG5115EVM. Note that there is an alignment hole in the EVM, the plastic will have a peg that aligns with a notch on the EVM and the cables must face the motor plate opening to allow all the cables to have an exit. 

Once seated correctly, we can reintroduce the screws to hold the EVM in place and reassemble the motor. Once reassembled, the second step is to connect the TMAG5115EVM to the MCT8316ZTEVM. To connect the TMAG5115EVM to the motor driver EVM, we will be connecting the thin, red, blue, green, white, and black wires to the J11 connector on the MCTEVM. 

The thin red wire should be connected to the H power pin, blue to the HPA, green to the HPB, white to the HPC and black to the A ground. We want to make sure that the J12 jumper is set to VBK and that the jumper is on J8 through J10 have been removed. 

The third step is to connect the three motor phase connections to the MCT8316ZTEVM. This is done by connecting the thick black, red, and yellow wires to connector J13. The yellow wire connects to out A. The red wire connects to out B. And the black wire connects to out C. 

Our fourth and final step is to complete the power and MSP430 connections. Connect the power supply to VM and P ground. Note that these connections can be made via the J7 connector and through the VM and P ground test points on the EVM. 

The USB connector must also be connected to a PC for GUI communication as well as to power the onboard MSP430. Setting the power supply to 24v with a current limit of 2 amps should be more than sufficient for this motor. Make sure that the potentiometer is turned fully clockwise to ensure the speed is zero upon power up. Enable the power supply and slowly turn the potentiometer to start spinning the motor. 

This concludes our demonstration and video on designing with Hall effect sensors. If you'd like to learn more about Hall effect sensors and BLDC motors, please read "Brushless DC Motor Commutation Using Hall Effect Sensors." To learn more about different commutation algorithms, please visit our Precision Lab series on brushless DC motors. To perform magnetic simulations please visit webench.Ti.com/timss. And finally, please visit ti.com/halleffect for more resources and tools. Thank you.