L4977A:7 A switching regulator

The L4977A is a stepdown monolithic power switching regulator delivering 7A at a voltage variable from 5.1 to 40V.

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.

Key Features

  • UNDER VOLTAGE LOCK OUT WITH HYSTERETIC TURN-ON
  • INPUT/OUTPUT SYNC PIN
  • VERY HIGH EFFICIENCY
  • PWM LATCH FOR SINGLE PULSE PER PERIOD
  • THERMAL SHUTDOWN
  • SWITCHING FREQUENCY UP TO 500KHz
  • CONTINUOUS MODE OPERATION
  • RESET AND POWER FAIL FUNCTIONS
  • PRECISE 5.1V ± 2% ON CHIP REFERENCE
  • 7A OUTPUT CURRENT
  • 0 TO 90% DUTY CYCLE RANGE
  • 5.1V TO 40V OUTPUT VOLTAGE RANGE
  • INTERNAL CURRENT LIMITING
  • SOFT START
  • INTERNAL FEED-FORWARD LINE REGULATION
产品规格
DescriptionVersionSize
DS0070: 7A switching regulator1.26 MB
Design Notes & Tips
DescriptionVersionSize
DN0011: ST1S03 alternative topology: Using a buck in a negative buck-boost configuration1.1359 KB
手册
DescriptionVersionSize
Brochure Power management guide05.20167 MB
样片和购买
型号PackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
L4977AMW 15LTube7.0941000NECEAR99MOROCCO
质量和可靠性
型号PackageGradeRoHS Compliance GradeMaterial Declaration**
L4977AMW 15LIndustrialEcopack1
7A switching regulator L4977A
circuit_diagram_1365_thumbnail.png L4977A
ST1S03 alternative topology: Using a buck in a negative buck-boost configuration L5986
Very low drop voltage regulators with inhibit KFXX