L4977A

® L4977A 7A SWITCHING REGULATOR 7A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REGULATION INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS SOFT START INPUT/OUTPUT SYNC PIN UNDER VOLTAGE LOCK OUT WITH HYSTERETIC TURN-ON PWM LATCH FOR SINGLE PULSE PER PERIOD VERY HIGH EFFICIENCY SWITCHING FREQUENCY UP TO 500KHz THERMAL SHUTDOWN CONTINUOUS MODE OPERATION DESCRIPTION The L4977A is a stepdown monolithic power switching regulator delivering 7A at a voltage variable from 5.1 to 40V. BLOCK DIAGRAM MULTIPOWER BCD TECHNOLOGY Multiwatt15V ORDERING NUMBER: L4977A Realized with BCD mixed technology, the device uses a DMOS output transistor to obtain very high efficiency and very fast switching times. Features of the L4977A include reset and power fail for microprocessors, feed forward line regulation, soft start, limiting current and thermal protection. The device is mounted in a 15-lead multiwatt plastic power package and requires few external components. Efficient operation at switching frequencies up to 500KHz allows reduction in the size and cost of external filter components. June 2000 1/21 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. L4977A ABSOLUTE MAXIMUM RATINGS Symbol V9 V9 V7 I7 V6 V3, V12 V4 I4 V5, V 10, V11, V13 I5 I10 I12 Ptot Tj, Tstg Input Voltage Input Operating Voltage Out...