Half-bridge motor driver for BLDCs eliminates heatsink in appliances

Branching out into motor drive ICs for brushless DC (BLDC) motors, Power Integrations has introduced the BridgeSwitch integrated half-bridge motor driver IC family. The ICs offer up to 98.5% efficiency for a range of appliances and industrial pumps.

They have high- and low-side fast recovery diode field effect transistors (FREDFETs) and integrated lossless current sensing. This combination results in up to 98.5% efficiency in BLDC motor drive applications, such as air conditioning, wet and cold appliances, e.g. washing machine and fridges, commercial pumps, fans and blowers and industrial pumps, says the company.

The IC eliminates the need for a heatsink, to reduce system cost and weight. The fast, soft-recovery body-diodes reduce losses during switching and reduce noise generation, to simplify system level EMC. The high-voltage, self-powered, half-bridge motor driver ICs have device protection, system monitoring and a robust single-wire status update interface which enables communication between the motor-microcontroller and up to three BridgeSwitch devices, each of which can be configured with different high- and low-side current limits, so there is no need for the system protection against open or shorted motor windings. Integrated loss-less current monitoring provides hardware-based motor fault protection to satisfy IEC60335-1 and IEC60730-1 requirements.

The IC also includes up to 20kHz PWM frequency, and a small signal output for 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, DC bus over-voltage and under-voltage protection and reporting.

For ease of use, they are compatible with all common control algorithms (field oriented control (FOC), sinusoidal, and trapezoidal modes with sensor and sensorless detection).

The company also offers reference designs for these modes.

The BridgeSwitch is available in the surface mount InSOP-24C package.