EL SEGUNDO, Calif., -- October 2004 -- International Rectifier, IR® (NYSE: IRF), a world leader in power management technology, today introduced the local interconnect network (LIN)-controlled alternator-regulator for next-generation vehicles. IR's solution optimizes performance in intelligent automotive charging systems for increased efficiency and improved fuel economy.

"Vehicle manufacturers are moving toward the integration of a single line, low speed, low cost communication bus. To enable this technology migration, IR has worked closely with its customers to be the first supplier of alternator-regulators with the LIN interface," said Ivo Jurek, Vice President, International Rectifier Automotive Products.

Intelligent vehicular charging systems are used when dynamic control of the alternator output and torque is desired for optimal battery charging, electrical system power management, and alternator-engine interaction. Dynamic alternator control enables improved electrical system efficiency and reduces engine idle speed for greater fuel economy.

"Previous intelligent charging systems utilized two-line analog communication to achieve limited dynamic control of the alternator through regulator set-point voltage. The IR LIN-controlled alternator-regulator uses more sophisticated serial communication for greater dynamic control and a greater range of alternator status feedback," Jurek added.

In contrast to analog interfaces, IR's platform offers integrated programmable load response control features, programmable field excitation of current or temperature and regulator feedback of fault status. As added benefits, IR's LIN solution can be uniquely addressed for compatibility with up to 15 other modules on the bus and all data can be transmitted or received in a single pass.

Technical Highlights

The LIN interface provides a simplified method of reliably achieving the bi-directional communication required for maximum alternator performance in an intelligent charging system. The LIN serial interface is used by the engine control unit (ECU) to transmit charging voltage setpoint from 10.7V to 16V, load response control ramp and cut-off speed and the field excitation limit. The voltage setpoint command can also disable the field driver for a momentary no-output condition.

Signals transmitted to the ECU from the regulator include field excitation duty cycle, current or temperature (customer-defined) and the fault status. Transmitted fault codes provide unique indication for mechanical, electrical, temperature, communication and timeout errors. In addition, the LIN-controlled alternator-regulator includes short-circuit protection, EMI and ESD suppression and consumes less than 200 microamps standby current.

The IR LIN-controlled alternator regulator is assembled using thick-film hybrid technology for reliable high temperature operation and excellent parametric stability over the entire operating temperature range of -40ºC to 150ºC. The hybrid circuit can be customized to the application to optimize performance and reliability, and can be assembled into a custom housing with an insert-molded lead-frame specifically designed for flame-soldering or heavy wirebonding.

Thick-film technology also enables precise laser trimming of discrete resistors so that patented current sensing technology can be used to achieve the highest tolerance capability in the industry.

IRVR101 LIN-controlled alternator-regulator

Function	Min	Typ	Max	Unit
Setpoint voltage range	10.7	-	16.0	V
Load response control range	0.4	-	13.2	s
LRC cut-off speed range	2400	-	8000	GRPM
Field excitation current limit range	2	-	7.75	A
Field excitation duty cycle limit range	0	-	100	%
Field excitation current feedback	0	-	7.75	A
Field excitation duty cycle feedback	0	-	100	%
Temperature range feedback	-29	-	157	ºC
Temperature feedback resolution		6		ºC
Base switching frequency	135	150	165	Hz
Field minimum duty cycle	-	3	-	%
Field maximum duty cycle	-	100	-	%

Pricing and Availability

The LIN-controlled alternator-regulator is custom-designed for specific applications. For availability and pricing information, contact the International Rectifier Automotive sales team at 248-347-1830, extension 110.