MC33092A

• Forced Load Response Control (LRC) with Heavy Load Transitions at Low RPM
• Capable of Regulating Voltage to ± 0.1 V @ 25
• Operating Frequency Selectable with One External Resistor
• < 0.1 V Variation over Speed Range of 2000 to 10,000 RPM
• < 0.4 V Variation over 10% to 95% of Maximum Alternator Output
• Maintains Regulation with External Loads as Low as 1.0 A
• Load Dump Protection of Lamp, Field Control Devices, and Loads
• Duty Cycle Limit Protection
• Provides High Side MOSFET Control of a Ground Referenced Field Winding
• Controlled MOSFET and Flyback Diode Recovery Characteristics for Minimum RFI
• < 2.0 mA Standby Current from Battery @ 25
• < 3.0 mA Standby Current from Battery Over Temperature Range
• Optional 2.5 or 10 sec. LRC Rate Control (Osc. Freq. = 280 kHz)
• Undervoltage, Overvoltage and Phase Fault (Broken Belt) Detection

The MC33092A is specifically designed for voltage regulation and Load Response Control (LRC) of diode rectified alternator charging systems, as commonly found in automotive applications. The MC33092A provides load response control of the alternator output current to eliminate engine speed hunting and vibration due to sudden electrical loads which cause abrupt torque loading of the engine at low RPM. Two load response rates are selectable using Pin 11. The timing of the response rates is dependent on the oscillator frequency.

In maintaining system voltage, the MC33092A monitors and compares the system battery voltage to an externally programmed set point value and pulse width modulates an Nchannel MOSFET transistor to control the average alternator field current.