What Is a BLDC Driver?

A bldc driver is an integrated circuit that controls current in a brushless DC motor. It eliminates brushes and commutator by sequentially energizing a series of stationary magnet coils.

BLDC drivers are used in consumer electronics such as fan and power tools, and medical devices like ventilators and centrifuges. They offer a balance of performance, reliability, and cost.

Power Circuit

The power circuit is the component in a bldc driver that handles the main current used to operate the motor. It includes power switching devices like MOSFETs and IGBTs that energize motor windings following commands from the control circuit. The command signals are generated by the control circuit based on information like the speed of the motor and its position. The proper commutation sequence is selected based on this information to avoid sparking or damaging the motor.

BLDC motors are increasingly replacing simple brushed DC motors in various applications due to their higher efficiency, low maintenance, and lower noise. They are often used as fans in electronic equipment like laptops, desktop PCs, and CD/DVD/Blu-ray players and in appliances like washing machines and dryers. They are also used in drone systems where precise motion control is critical.

The most advanced BLDC motor technologies use Field-Oriented Control (FOC) to optimize the currents in the motor windings and achieve constant speeds, torque, and position. These drivers are typically more expensive than their simpler brushed counterparts but offer advantages in areas like reduced mechanical stress and power consumption.

Control Circuit

BLDC motor controllers control the current injected into the rotor’s windings to generate optimum torque. They do this by detecting the rotor’s position either with Hall sensors or through a sensorless technique that estimates back electromotive force (back EMF), the voltage created in the stator’s windings when the armature is close to the rotor magnet. A microcontroller (MCU) then translates this position information into the proper sinusoidal commutation signals by changing the PWM duty cycle. These signals then turn power MOSFETs on and off to energize the windings in the correct order.

To reduce system complexity, many BLDC drivers combine the power and control stages into a single package. This integrated solution simplifies layout and assembly, as well as reducing component cost.

In addition to simplifying the design, this approach also provides thermal performance advantages for a given application. It’s a popular choice for automotive, industrial automation, bldc driver and consumer electronics applications where reliable, low-maintenance motor operation is essential.

BLDC motors use electronic commutation instead of brushes and a commutator, delivering better speed, efficiency, and reliability in a smaller package. These features make them ideal for drone systems and other precision applications, as well as appliances like fans and pumps. They’re also found in medical devices, including infusion pumps and centrifuges, for critical healthcare applications. They’re also used in industrial automation, bringing precise motor control to conveyor systems and robotic arms.

Commutation Logic

The commutation logic in a bldc driver is what makes the motor’s phase-shifted sinusoidal current waveforms possible. This enables more efficient and smoother motor operation while significantly reducing torque ripple and noise level.

Hall effect sensors have traditionally been the workhorses for commutation feedback. Their simple design and low per-unit cost are ideal for achieving commutation at the lowest possible BOM cost. However, these sensors are limited in how much position information they can provide to a controller: only six states per electrical revolution of a two-pole motor. As the use of BLDC drivers in applications such as industrial automation, electric vehicles, and consumer electronics continues to grow, the need for accurate rotor position sensing is growing as well.

To address this need, TI offers sensor-based BLDC drivers that combine the functionality of both a Hall effect sensor and an incremental encoder on one board. These BLDC drivers allow you to achieve better speed regulation, reduced noise levels, and enhanced positioning accuracy, all while saving space in your system.

The TMAG5115EVM is a plug-in replacement for the Hall-effect sensor boards found in most NEMA17 BLDC motors and combines the control circuitry, power MOSFETs, current sense capabilities, and protection features in a single package. This makes it easy for engineers to get started with a bldc motor controller without the need for external components or the expense of adding an incremental encoder to their design.

Motor Driver ICs

Motor driver integrated circuit chips serve as an interface between the control signal of a microprocessor or microcontroller and the motor. They incorporate power transistors or MOSFETs that handle high current and voltage levels, as well as control functions like current sensing amplifiers. They also offer protection features to safeguard against over-temperature or overcurrent conditions.

RS offers a wide selection of dedicated motor drivers for brushed DC and brushless DC (BLDC) bldc driver manufacturer motors, as well as stepper motors. These motor driver ICs eliminate the need for external components by combining a power stage, current sensing and protection circuitry in one package. This helps to reduce total system cost and power consumption, as well as minimizing component count and improving design reliability.

Brushed DC motor drivers are typically used to drive cooling fans in electronic devices or white goods. Brushed DC motors use brushes and a mechanical commutator to deliver the voltage and current needed to the motor coils. BLDC motors, on the other hand, have an electronic commutator that removes the need for brushes.

Infineon offers a range of automotive qualified motor control solutions that provide maximum flexibility and safety features in a single package. Our MOTIX(tm) Motor System IC combines both motor control (full-bridge and half-bridge motor gate drivers) and a low-dropout voltage regulator with CAN FD and LIN functionality to simplify the design of battery-powered cordless tools, gardening products or automated guided vehicles.