Freescale Adds to Analog Product Portfolio for Engine Control

Freescale Semiconductor is introducing six standard SMARTMOS™ analog products designed for engine management applications. Freescale’s portfolio of analog products for high-current powertrain applications includes output drivers, signal monitoring and conditioning devices, and H-bridges. These products can be mixed and matched with Freescale’s complementary MPC55xx 32-bit microcontrollers (MCUs), providing the flexibility to support a wide variety of multi-cylinder engine control applications. Built on Power Architecture™ technology, MPC55xx MCUs are fully synthesizable system-on-chip (SoC) devices optimized for automotive applications, including powertrain control.

The MC33800 is a 16-channel, multifunction output driver featuring eight low-side drivers, six field-effect transistor (FET) pre-drivers and two constant current low-side drivers. A "Swiss Army knife" of MCU interfaces, the MC33800 is designed to control relays, motors, solenoids, lamps, valves and heated exhaust gas oxygen (HEGO) sensors. While suitable for engine and transmission control, the device is also well-suited for many other applications, such as electronic power steering, four-wheel drive control, and industrial and commercial control systems requiring low-side drivers with diagnostic reporting and fault protection.

The MC33810 low-side driver provides a versatile, programmable interface between the engine control MCU and the spark ignition and fuel injection functions of a gasoline engine. Applications include automobiles, motorcycles, industrial engines, generators, marine craft and other recreational vehicles. The MC33810 is claimed to be one of the first flexible engine control interface circuits that scales easily for various numbers of engine cylinders. The device integrates four low-side drivers and four PWM-capable pre-drivers that can be configured to drive fuel injectors, solenoids, external FETs or IGBTs. The MC33810 is said to significantly reduce the number of components in an engine control unit, reducing its size, cost and complexity.

The MC33811 is a five-channel solenoid monitoring device used to determine the correct operation of a solenoid. The device determines whether there is a problem with a solenoid opening and closing by monitoring the profile of the solenoid’s current waveform. A simple SPI message tells the MCU if the solenoid actuation has been successful or if a fault has occurred. Applications include automatic transmissions, fuel injectors and other control valve actuators.

The MC33975 is an enhanced interface IC designed to detect the state of 22 switch inputs: 14 switch inputs to ground and eight switch inputs for contacts to ground or to battery. All 22 inputs can be configured as analog signal inputs multiplexed and buffered for use by off-chip circuitry. A member of Freescale’s Multiple Switch Detection Interface family, the MC33975 can connect to any SPI-enabled MCU, providing a protected switch-level interface and an analog input signal capability. The device has been enhanced to provide 32 mA of current per output to switched 5V sensors, as well as input sensing. The MC33975 also can be used in automotive body control modules and in industrial and commercial control systems.

The MC33899 and MC33926 devices are monolithic H-bridge power ICs designed for electronic throttle control and low-voltage dc servo motor control applications. The devices can drive dc motors or bi-directional solenoid-controlled actuators, such as throttle control or exhaust gas recirculation actuators. They are also said to provide robust solutions for harsh powertrain environments in a compact, easy-to-use package.

The MC33899 features a SPI interface to the system MCU to enable advanced diagnostics, programmable current limit and a selectable slew rate. It also offers a higher output current than the MC33926. A fault restart feature allows the MC33899 to be configured to regulate high load currents below the programmed current limit.

The MC33926 offers a simple input control to enable precise load management without a SPI interface. The device’s rich feature set is a subset of the broad programmability of the MC33899. The MC33926 also has a smaller footprint package than the MC33899. This thermally enhanced compact PQFN package makes the MC33926 a suitable solution for small-footprint engine controllers.

Freescale’s analog SMARTMOS devices for engine control are sampling upon request. These devices are supported by evaluation boards and a USB to SPI interface board. The KITUSBSPIEVME board enables a PC without a parallel port to communicate with other Freescale evaluation boards via a USB port. Suggested resale pricing for the KITUSBSPIEVME is $65 (USD).