Freescale has launched six standard analog products flexible enough, it said, to provide a faster time-to-market alternative to custom-designed application-specific integrated circuits (ASICs ) in engine control applications. The products include two signal monitoring/conditioning devices (MC33811 and MC33975), two H-bridge ICs (MC33899 and MC33926), and two output drivers (MC33800 and MC33810). All six are fabricated in SMARTMOS, a CMOS variant with additional metallization layers and isolation to accommodate higher current and higher voltages.
Kevin Anderson, Freescale’s marketing systems and applications manager for analog products, said the new standard analog products can be mixed and matched with Freescale’s 32-bit MPC55xx power architecture microcontrollers (MCUs) to address a variety of multicylinder engine control applications.
The MC33811 is a five-channel device that monitors a solenoid’s current waveform to determine whether the solenoid is operating as it should. Designed for use with automatic transmissions, fuel injectors and other control valve actuators, the device sends a message via its serial peripheral interface (SPI) that tells the microcontroller if the solenoid actuation has been successful or a fault has occurred.
The MC33975 is an interface IC for body control modules. Connected to an SPI-enabled MCU, it can detect the state of 22 switch inputs, including 14 to ground and eight for contacts to ground or to battery. All 22 can be configured as analog signal inputs, multiplexed and buffered for use by off-chip circuitry. Freescale has enhanced the device to provide 32 mA of current per output to switched 5 V sensors.
Freescale’s MC33899 H-bridge device features a SPI interface to the system MCU for programming a current limit or selecting a slew rate, or for advanced diagnostics. A fault restart feature allows the device to be configured to regulate high load currents below the programmed current limit. The MC33926 H-bridge device offers a simple input control for precise load management without an SPI interface. With a subset of the MC33899’s programmable features, a lower output current, and a smaller (PQFN) package, the MC33926 targets small-footprint engine controllers.
The MC33800 is a16-channel, multifunction output driver with eight low-side drivers, six field-effect transistor (FET) pre-drivers, and two constant current low-side drivers. It’s designed to control relays, motors, solenoids, lamps, valves and heated exhaust gas oxygen (HEGO) sensors. Target applications include engine and transmission control, electronic power steering, and four-wheel drive control.
The MC33810 low-side driver provides a programmable interface between the engine control MCU and the spark ignition and fuel injection functions of a gasoline engine. Intended to reduce the number of components required for engine control, 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.