Three Industry Powerhouses Debut BLDC Motor Control Solutions
Infineon, Power Integrations and Microchip have each introduced solutions to ease brushless DC motor (BLDC) control this month.
Within the span of a week, power industry giants Infineon, Power Integrations, and Microchip introduced a slew of BLDC motor control solutions earlier this month.
Those solutions include options for integrating microcomputers, drivers and FETs, as well as methodologies for detecting rotor positions that do not incorporate the Hall Effect.
Infineon’s 3-phase Gate Driver/MCU Tandem
Last Monday, Infineon announced its MOTIX IMD70xA (IMD700A and IMD701A) programmable controllers for BLDCs. Showcased last week at Embedded World in Nuremberg, Germany, the new units integrate the company’s MOTIX 6EDL7141 3-phase gate driver IC with its XMC1404 MCU in a single 64-pin, 9 x 9 mm2 VQFN package.
The MOTIX IMD70xA in a Hall-sensored BLDC motor control system. Screenshot used courtesy of Infineon
The units are aimed at battery-operated products using BLDC or permanent magnet synchronous motors (PMSMs), and feature an operating voltage range of 5.5 to 60 V.
Driver Section
The 6EDL7141’s flexible, 3-phase gate driver section can be configured to provide sink and source currents up to 1.5 A. The section also sports adjustable gate driver supply voltage settings of between 7, 10, 12 and 15 volts; thanks to built-in high and low–side charge pumps, it can achieve this even at low battery voltage.
To minimize EMI, the section has adjustable gate driver parameters to enable control of the slew rate. Infineon also provides PC-based GUI tools to simplify setting adjustments.
MCU Section
Per Infineon’s announcement release, the XMC1404 MCU section inherits most of the peripherals optimized for motor control found in the XMC4000 family. These include PWM timers, position interface (POSIF), and serial communication modules (including CAN). Included is a programmable, drives-optimized ARM Cortex-M0 microcontroller with a 48 MHz main clock, and an additional 96 MHz MATH co-processor.
Applications include cordless power tools, gardening products, drones, e-bikes, and automated guided vehicles.
Power Integrations’ Control Software
Announced last Tuesday, Power Integrations’ fresh control software targets the company’s BridgeSwitch integrated half-bridge motor driver. The software incorporates Power Integration’s extant Motor-Expert configuration and diagnostics tool, and is fittingly dubbed Motor-Expert 2.0.
A typical BridgeSwitch 3-phase inverter schematic. Screenshot used courtesy of Power Integrations
The company claims this hardware-software solution enables motor control solutions of 98.2% efficiency.
What’s more, Infineon says the setup requires just three components for the current feedback circuitry, compared to the 30 of a discrete solution. That makes for a 70% reduction in board footprint.
The BridgeSwitch Family
Devices in Power Integrations’ BridgeSwitch family incorporate both the drivers and the output FETs in the same package. These N-channel “FREDFETs” can each work with up to 600 V, and provide DC outputs ranging from 1 to 11.5 A at a peak of 400 W.
What on Earth are FREDFETs?
We were curious, too. Robert Keim, a prolific writer for our sister publication AllAboutCircuits, provided the answer to this amusing question back in 2020.
Applications for the New Power Integrations Solution
Primary applications include residential and commercial appliances employing three-phase motors. These include air conditioner fans, high-speed hair dryers, refrigerator compressors, range hood fans, and water pumps.
Microchip’s Hall Effect-absent IC
With its new position sensor, announced June 15, Microchip has enabled developers to eschew expensive, inaccurate Hall Effect and magnetic resolver rotor position sensing. The LX34070 employs an inductive methodology to eliminate costly magnets and other heavy, transformer-based structures, allowing engineers to incorporate the device onto simple, compact PCBs.
The LX34070. Image used courtesy of Microchip
The device, which is but one member in a family of inductive position sensors touted by Microchip as the industry’s largest, has been specifically designed for EV motor control applications. Critically, the AEC-Q100, Grade 0-qualified unit is functional-safety-ready for ISO 26262 compliance in the Automotive Safety Integrity Level–C (ASIL–C) classification, Microchip said in its announcement release.
How It Works
In employing inductive position sensing, the LX34070 utilizes PCB traces rather than transformer-based magnetic windings and coil structures.
A primary coil is used to generate an AC magnetic field that couples with two secondary coils. Then, a small metal target object disturbs the magnetic field so that each secondary coil receives a different voltage; the voltage ratio is used to calculate absolute position. The elimination of the heavy magnetics makes for a far lighter solution.
Per Fanie Duvenhage, vice president of Microchip’s mixed signal and linear analog business unit, users can streamline EV motor control designs by pairing the LX34070 with the company’s 8-bit AVR and PIC µCs, its 32-bit µCs, or its dsPIC digital signal controllers.
