The move away from AC-DC motors to brushless DC (BLDC) motors reflects a disruptive change and Power Integrations has seized the opportunity to enter the highly integrated, highly efficient billion dollar motor drive market with their BridgeSwitch integrated half-bridge (IHB) motor driver IC family.
“We saw the increasing adoption of BLDC motors worldwide in industrial fans, compressors, pumps, washing machines, fans, air-conditioning units and decided we wanted to be part of this vast market. But we had to have something that makes a difference,” said Peter Rogerson, Senior Director of Marketing and Communications at PI. “Since we weren’t previously in this market, we believe we came in with a different view from what the other legacy players were doing and entered with a fundamentally new approach. As a result, we can now offer devices that eliminate the need for heat sinks, increase product lifetime and efficiency, and make requalification easy.”
The BridgeSwitch ICs feature high- and low-side advanced FREDFETs (Fast Recovery Diode Field Effect Transistors) with integrated lossless current sensing, resulting in inverter conversion efficiency of up to 98.5% in brushless DC (BLDC) motor drive applications to 300 W. Superior efficiency along with the distributed thermal footprint provided by the IHB driver eliminates the need for a heatsink, reducing both system cost and weight. Integrated lossless current sensing, bus voltage sensing and system-level thermal sensing makes this device family ideal for BLDC motors in home-appliance applications. BridgeSwitch devices target refrigerator compressors, HVAC system fans and other residential and light commercial pumps, fans and blowers.
The 600 V FREDFETs used in BridgeSwitch ICs incorporate fast, ultra-soft-recovery body-diodes. This drastically reduces losses during switching and reduces noise generation, which simplifies system level EMC. The new high-voltage, self-powered, half-bridge motor driver ICs also feature built-in device protection and system monitoring and a robust single-wire status update interface which enables communication between the motor-microcontroller and up to three BridgeSwitch devices. Each BridgeSwitch device may be configured with different high- and low-side current limits, eliminating the need for the microcontroller and external circuitry to protect the system from open or shorted motor windings. Integrated loss-less current monitoring provides hardware-based motor fault protection, which simplifies the task of providing protection under motor-fault conditions to satisfy IEC60335-1 and IEC60730-1 requirements.
Other features include up to 20 kHz PWM frequency, and a small signal output that provides accurate, real-time reporting of FREDFET drain current which mirrors the positive motor winding current. Safety features include two-level device over-temperature detection, low-side and high-side cycle-by-cycle current limit, as well as DC bus overvoltage and undervoltage protection and reporting. Devices are compatible with all common control algorithms – field oriented control (FOC), sinusoidal, and trapezoidal modes with sensor and sensorless detection, which are described in reference designs DER-654, DER-653 and DER-749. BridgeSwitch is available in InSOP-24C – a small surface-mount package offering creepage distances greater than 3.2 mm and enabling PCB heatsinking via two exposed pads.
Samples of BridgeSwitch ICs are available now and are priced at $1.69 in 10,000-piece quantities.