Freescale cleans up small combustion engines with electronic control solution

The platform consists of the MCZ33812, an advanced analog integrated circuit (IC) optimized to control fuel and spark in EFI and electronic carburetion (e-carb) systems, and a Freescale S12 MCU. This comprehensive small engine control platform helps lower harmful emissions and reduces system complexity, bill of materials and manufacturing cost, while accelerating time to market.

“State-of-the-art electronic control helps small engines produce more horsepower and less pollution than their carbureted predecessors,” said Steve Nelson, global manager of automotive marketing at Freescale Semiconductor. “Emissions regulations are influencing small engine design, and the evolution from mechanical to electronic control is transforming the small-displacement motorcycle and scooter market. Freescale has long been a pioneer in advanced engine technology for automobiles, and our new platform solution is an important step on the path to greener small engines.”

Target applications for Freescale’s small engine control platform include small-displacement two- and four-stroke engines used in motorcycles, mopeds, scooters and three-wheeled taxis. The platform is also ideal for small engine designs in a wide range of outdoor power equipment, such as lawnmowers, garden tractors, trimmers, edgers, chainsaws, snow and leaf blowers, tillers, electrical generators and outboard motors.

The demand for low-cost, two- and three-wheeled motorized vehicles is on the rise in emerging markets, such as China, India and Brazil. These small engines – especially carbureted two-stroke designs, which represent the majority of small engines in Asia – are major sources of air pollution. A three-wheel taxi with a two-stroke engine can produce harmful emissions equivalent to about 50 modern automobiles.

Governments worldwide are implementing stringent regulations requiring motorbike and outdoor equipment manufacturers to design cleaner-burning small engines. Emerging markets for motorbikes are adopting emissions standards similar to Euro 3. The U.S. Environmental Protection Agency (EPA) also has enacted strict emissions rules for small engines. According to the Outdoor Power Equipment Institute, the EPA Phase 3 standards, when fully implemented in the U.S. by 2015, are expected to reduce harmful emissions from small gasoline engines by 95 percent, compared to 1997 levels.

The most feasible way for small engine makers to meet tougher, government-mandated emissions regulations is to deploy electronic engine controls, such as electronic ignition, e-carb and ultimately EFI. Implementing EFI systems on small engines can help reduce carbon monoxide emissions by up to 65 percent, hydrocarbons by up to 35 percent and nitrogen oxide by up to 35 percent compared to carburetor systems. EFI-equipped small engines also increase horsepower and improve gas mileage.

Broad deployment of advanced electronic controls for small engines requires highly integrated and affordable components. Freescale’s new MCZ33812 analog IC represents breakthrough technology for this market. The device combines a voltage regulator, fuel injector driver and ignition pre-driver, as well as a relay and lamp driver, watchdog timer and reset generator – all optimized for small engine control. This exceptional integration, enabled by Freescale SMARTMOS™ technology, eliminates up to a dozen discrete components and reduces the circuit board area for engine makers while also helping customers enhance the quality and reliability of their products.
To help the small engine market migrate from mechanical/carburetor-based systems to electronic control and fuel injection, Freescale provides a comprehensive system solution featuring a hardware/software reference design to speed the development process. Freescale’s off-the-shelf MCZ33812 Reference Design allows developers to evaluate a two-chip solution based on the MCZ33812 and S12P MCU and emulate a complete small engine electronic control unit (ECU). Freescale also provides optimized software device drivers and engine control software for small-displacement designs. The reference design enables calibration engineers and ECU hardware and software designers to work in parallel, streamlining development and speeding time to market.

The S12/S12X MCU family is the most widely adopted 16-bit architecture in the automotive market. The MCZ33812 IC and S12P MCUs provide an ideal combination for small engine control designs. The S12P delivers the performance benefits of a 16-bit MCU while supporting the entry-level pricing, low power, electromagnetic compatibility (EMC) and code-size efficiencies of an 8-bit MCU. The scalable S12P family offers a range of price/performance options and offers a smooth migration path to the more powerful S12XS family and to S12XE devices with performance-boosting XGATE technology. This compatibility enables developers to scale their small engine designs as their flash memory and performance requirements increase.

MCZ33812 small engine control circuit features

* 1 fuel injector low-side driver (current limit – 4.0 A typical)
* 1 relay, fuel pump or second injector low-side driver (current limit – 4.0 A typical)
* 1 lamp low-side driver (current limit – 1.5 A typical)
* 1 ignition pre-driver with independent high- and low-side outputs
* For full list of product details, visit www.freescale.com/smallengine