The 33813 is an engine control analog power IC intended for one cylinder motorcycle and other small engine control applications. The IC consists of five integrated low side drivers, two pre-drivers, a VRS (variable reluctance sensor) input circuit, a voltage pre-regulator using an external pass transistor, and two 5.0 volt internal regulators, one for the microcontroller (MCU) VCC supply and the other for use as a protected sensor supply. Also included is an MCU reset control circuit with watchdog, a ISO 9141 K-Line interface for diagnostic communication and a SPI (serial peripheral interface). The five low side drivers are intended for driving a fuel injector, a lamp, two relays or other loads and a tachometer. The pre-drivers are intended to drive IGBT or MOSFET transistors to control ignition coils, and/or a HEGO heater. The device is packaged in a 48 pin LQFP with an exposed pad.
- Designed to operate over supply voltage range of 4.5 V ≤ VPWR ≤ 36 V
- Logic stability guaranteed down to 2.5 V
- One fuel injector driver – typically 1.3 A
- One ignition IGBT or general purpose gate pre-driver
- One O2 sensor (HEGO) heater general purpose gate pre-driver
- Relay 1 driver, typically 2.0 A, can be used for fuel pump control
- Relay 2 driver, typically 1.0 A, can be used as power relay control
- Lamp driver, typically 1.0 A can also be used to drive an LED
- VPROT protected sensor supply tracks VCC +5.0 V regulator
- MCU reset generator – system integrity monitor (watchdog)
- VPP pre-regulator provides power for VCC and VPROT regulators
- Independent fault protection with all faults reported via the SPI
- ISO 9141 K-Line interface for communicating diagnostic messages
- Start-up/shut-down control and power sequence logic for power control
- Interfaces directly to MCU using a 5.0 V SPI and logic I/O
- Differential/single-ended VRS conditioning circuit with auto/manual selected thresholds and filter times with digital and tachometer outputs
- Keyswitch logic with provision for power relay and MCU controlled shutdown.
For small petrol engines, Freescale has introduced an analogue mop-up chip to fire the ignition, pump the fuel injection, and read sensors in engine management systems.
“Small engine makers are increasingly deploying electronic engine controls, including EFI or e-Carb and electronic ignition for motor bikes, motor scooters and power equipment,” said Gavin Woods, v-p of Freescale’s analogue division. “Current solutions rely mainly on discrete components. This device integrates the requirements of tier-one ECU [engine control unit] developers who supply motorcycle and scooter manufacturers.”
There are two chips, both designed to work with a microcontroller to handle the digital side:
“The ICs compliment and extend Freescale’s motorcycle ECU reference platform, which retains the MC9S12 microcontroller but benefits from further integration and improved diagnostic capabilities,” said Freescale.
MC33813 is for one-cylinder engines, and has five low-side drivers and two pre-drivers.
For more read: Chip has all analogue for engine management