International Rectifier has introduced a LIN-controlled alternator-regulator (IRVR101) designed to optimize performance in next-generation intelligent automotive charging systems for increased efficiency and better fuel economy.
Intelligent charging systems provide dynamic control of the alternator output and torque 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," notes Ivo Jurek, IR's vice president for automotive products.
Previous intelligent charging systems used two-line analog communication to achieve limited dynamic control of the alternator through regulator set-point voltage, according to Jurek, whereas IR's LIN-controlled alternator-regulator uses more sophisticated serial communication for greater dynamic control and a greater range of alternator status feedback.
"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." It can also 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.
Jurek says the LIN interface provides a simple and reliable way to achieve the bidirectional communication needed 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 fault status. Transmitted fault codes provide unique indication for mechanical, electrical, temperature, communication, and timeout errors. The LIN-controlled alternator-regulator also includes short-circuit protection and EMI and ESD suppression, and consumes less than 200 microamps standby current.
Thick-film hybrid technology provides reliable high temperature operation and parametric stability over the alternator regulator’s -40 degrees to +125 degree C operating temperature range, according to Jurek, and also enables precise laser trimming of discrete resistors. Patented current sensing technology can be used to achieve high tolerance capability. The thick film hybrid circuit can be customized for 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.
A data sheet on the LIN-controlled alternator-regulator is available at www.irf.com/product info/datasheets/data/irvr101.pdf