L4992

® L4992 TRIPLE OUTPUT POWER SUPPLY CONTROLLER DUAL PWM BUCK CONTROLLERS (3.3V and 5.1V) 12V/120mA LINEAR REGULATOR DUAL SYNCH RECTIFIERS DRIVERS 96% EFFICIENCY ACHIEVABLE 50µA (@ 12V) STAND BY CONSUMPTION 5.5V TO 25V SUPPLY VOLTAGE EXCELLENT LOAD TRANSIENT RESPONSE DISABLE PULSE SKIPPING FUNCTION POWER MANAGEMENT: - UNDER AND OVERVOLTAGE OUTPUT DETECTION - POWER GOOD SIGNAL - SEPARATED DISABLE THERMAL SHUTDOWN PACKAGE: TQFP32 APPLICATION NOTEBOOK AND SUBNOTEBOOK COMPUTERS PEN TOP AND PORTABLE EQUIPMENT COMMUNICATING COMPUTERS DESCRIPTION The L4992 is a sophisticated dual PWM stepdown controller and power monitor intended for Notebook computer and/or battery powered equipment. The device produces regulated +3.3V, +5.1V and 12V supplies for use in portable SYSTEM BLOCK DIAGRAM TQFP32 ORDERING NUMBER: L4992 and PCMCIA applications. The internal architecture allows to operate with minimum external components count. A very high switching frequency (200/300 KHz or externally synchronizable) optimizes their physical dimensions. Synchronous rectification and pulse skipping mode for the buck sections optimise the overall efficiency over a wide load current range (96% efficiency @1A/5.1V and 93% efficiency @ 0.05A/5.1V. The two high performance PWM controllers for +3.3V and +5.1V lines are monitored for overvoltage, undervoltage and overcurrent conditions. On detection of a fault, a POWER GOOD signal is generated and a specific shutdown procedure takes place to prevent physical dam...