Freescale Launches Analog Pre-Driver For Automotive Motor Control

Austin, TX - Freescale Semiconductor has introduced a versatile field effect transistor (FET) pre-driver designed for three-phase motor control in a wide range of automotive and industrial control applications.

The MC33927 pre-driver provides a cost-effective, comprehensive solution for cooling fans, water pumps, fuel pumps, and electro-hydraulic and electric power steering used in automobiles, electric scooters and electric-assist bicycles. These applications require synchronous and asynchronous three-phase motors to combine high output performance, high reliability and small size for space-constrained designs.

Based on Freescale's SMARTMOS technology, the MC33927 integrates the following advanced features that help simplify motor control:

• Industry's widest voltage range in a single pre-driver device. The device supports the entire automotive range from 6V to 58V, which enables reduced inventory or a single development module for multiple platforms.
• Programmable dead time delay. Adjustable delay helps eliminate current shoot through (crossover) and increases performance.
• Full pulse width modulation (PWM) range. It can support from 0% to 100% PWM control of the load for increased motor efficiency and control.
• Extensive diagnostic and self protection capabilities. The pre-driver provides protection and works in concert with microcontrollers (MCUs).

The MC33927 enables precise and efficient control from less than 6V to more than 55V.

The device's logic interfaces easily with the latest 3V systems, as well as established 5V platforms. The MC33927 interfaces to a 5.0V or 3.0V MCU 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. "Our latest pre-driver provides developers with 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 both high-side and low-side FETs from conducting simultaneously and has a programmable deadtime from zero µs to more than 10.5µs. This complementary phase control logic can be turned off for explicit control of each driver, a desirable feature for switched reluctance applications.

MC33927 product features

• Fully specified from 8.0V to 40V, covering 12V and 24V automotive systems
• Extended operating range from 6.0V to 58V, covering 12V and 42V systems
• 1.0A gate drive capability with protection
• Protection against reverse charge injection from C^GD and C^GS of external FETs
• Integrated charge pump to support full FET drive at low battery voltages
• Deadtime is programmable via the SPI port
• Integrated op amp for current feedback
• Simultaneous output capability enabled via safe SPI command
• Lead-free packaging

SOURCE: Freescale Semiconductor