L4974A:3.5 A switching regulator

The L4974A is a stepdown monolithic power switching regulator delivering 3.5A 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 L4974A include reset and power fail for microprocessors, feed forward line regulation, soft start, limiting current and thermal protection. The device is mounted in a Powerdip 16 + 2 + 2 plastic package and requires few external components. Efficient operation at switching frequencies up to 200KHz allows reduction in the size and cost of external filter component.

Key Features

  • PWM LATCH FOR SINGLE PULSE PER PERIOD
  • UNDER VOLTAGE LOCK OUT WITH HYSTERETIC TURN-ON
  • SWITCHING FREQUENCY UP TO 200KHz
  • VERY HIGH EFFICIENCY
  • CONTINUOUS MODE OPERATION
  • THERMAL SHUTDOWN
  • RESET AND POWER FAIL FUNCTIONS
  • PRECISE 5.1V ± 2% ON CHIP REFERENCE
  • 3.5A OUTPUT CURRENT
  • 0 TO 90% DUTY CYCLE RANGE
  • 5.1V TO 40V OUTPUT VOLTAGE RANGE
  • INTERNAL CURRENT LIMITING
  • INPUT/OUTPUT SYNC PIN
  • INTERNAL FEED-FORWARD LINE REG.
Product Specifications
DescriptionVersionSize
DS0068: 3.5A switching regulator2.26 MB
Design Notes & Tips
DescriptionVersionSize
DN0011: ST1S03 alternative topology: Using a buck in a negative buck-boost configuration1.1359 KB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
L4974APDIP 20Tube5.1081000NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
L4974APDIP 20IndustrialEcopack1
3.5A switching regulator L4974A
circuit_diagram_1363_thumbnail.png L4974A
ST1S03 alternative topology: Using a buck in a negative buck-boost configuration L5986
Very low drop voltage regulators with inhibit KFXX