Power Integrations Half-bridge motor drive IC replaces MOSFETs with programmable protection levels

     PI's half-bridge motor drive circuit is used with household 30-300W electrical DC motors, especially for BLDC programmable efficiency, but not suitable for battery-powered low-voltage DC motor applications. The half-bridge driver can replace MOSFETs and drive IGBTs more safely because of its high heat dissipation efficiency and no heat sink is required. From the internal structure of the chip, the driver has the ability of self-power supply, and the circuit protection level can be set according to the application.

     Power Integrations, Inc. announces BridgeSwitch's line of motor driver ics with integrated half-bridge circuits (IHB). The BridgeSwitch IC integrates two enhanced FREDFETs (field effect transistors with fast recovery epitaxial diodes) for the upper and lower tubes of the half-bridge circuit, and has lossless current detection function. Inverter conversion efficiency up to 98.5% in brushless direct current (BLDC) motor driver applications up to 300 W.

     The excellent efficiency and distributed heat dissipation method offered by IHB drivers eliminates the need for heat sinks, helping to reduce system cost and weight. Due to its integrated lossless current detection, bus voltage detection, and system-level overtemperature detection, the device family is ideal for BLDC motor drive applications in home appliances. BridgeSwitch devices are suitable for refrigerator compressors, HVAC system fans, and other domestic and light commercial pumps, fans, and fans.

     The 600 V FREDFET used in the BridgeSwitch IC incorporates a fast ultra-soft recovery diode. This helps to significantly reduce switching losses and reduce noise generation, thereby simplifying system-level EMC design. The new high-voltage self-powered half-bridge motor driver IC also features built-in device protection and system monitoring, as well as a reliable single-wire interface for operating status updates and communication between the motor microprocessor and up to three BridgeSwitch devices. The upper and lower limit points of each BridgeSwitch device can be set individually, which eliminates the need for the microprocessor and associated peripheral circuits to protect the entire system from open or short circuits in the motor windings. The integrated lossless current monitoring feature provides hardware-based motor fault protection, helping to simplify motor fault protection mechanisms to meet IEC60335-1 and IEC60730-1 requirements.

     Cristian Ionescu-Catrina, Senior Product Marketing Manager, said: "We re-examined the challenges of the rapidly growing BLDC market and the increasingly stringent energy conservation standards and regulations around the world, and came up with an innovative solution that enables both energy and space savings while streamlining the BOM. The new solution not only makes it easy to meet safety standards, but also simplifies the circuit and reduces development time."

     Other features of the new device include a PWM operating frequency of up to 20 kHz, while also providing a small signal output that reflects the precise, real-time FREDFET drain current, whose amplitude is mirrored by the forward current of the motor windings. Its safety features include two-stage device overtemperature detection, cycle current limiting of lower and upper tubes, and DC bus overvoltage and undervoltage protection and reporting.

     The new device is compatible with all common control algorithms-field oriented control (FOC), sine control, and ladder control algorithms that provide sensorless and sensorless detection-see Reference Design DER-654, DER-653, and DER-749 for all three control modes. The BridgeSwitch is packaged in a thin surface mount INOP-24C package with a creepage distance greater than 3.2 mm and allows heat dissipation using PCBS via two bare pads.