Freescale Semiconductor has introduced the MC33927, an analog field effect transistor (FET) pre-driver for controlling synchronous and asynchronous three-phase motors in automotive applications that require high output performance, reliability, and small size. Examples include cooling fans, water pumps, fuel pumps, and electrohydraulic and electric power steering.
The chip, which is based on Freescale’s SMARTMOS technology, features a voltage range from 6 V to 58 V, thus reducing inventory requirements for multiple applications and platforms. It also offers programmable dead time delay, to improve performance and help eliminate current shoot-through (crossover), and 0% to 100% pulse width modulation (PWM) control for better motor efficiency. Diagnostic and self-protection capabilities are also included.
The device’s logic interfaces easily with 3 V systems as well as 5 V platforms. It can be interfaced to a 5.0 V or 3.0 V microcontroller via six direct input control signals, a serial peripheral interface (SPI) port for device setup, and asynchronous reset, enable and interrupt signals.
“By combining many advanced control features in a single device, the MC33927 is ideally suited for fractional to integral horsepower motor control,” said Arman Naghavi, vice president and general manager of Freescale’s Analog, Mixed-Signal & Power Division. “This pre-driver provides a high level of flexible control for such capabilities as phase timing, protection and diagnostics.”
The device is designed to enable precision control of motor speed, torque and power. The phase control logic prevents high-side and low-side FETs from conducting simultaneously, and has a programmable deadtime from zero µs to more than 10.5 µs. Complementary phase control logic can be turned off for explicit control of each driver in switched reluctance applications.
