L4978:2A Step down switching regulator

The L4978 is a step down monolithic power switching regulator delivering 2A at a voltage between 3.3V and 50V (selected by a simple external divider). Realized in BCD mixed technology, the device uses an internal power D-MOS transistor (with a typical Rdson of 0.25Ω) to obtain very high efficency and high switching speed.

A switching frequency up to 300KHz is achievable (the maximum power dissipation of the packages must be observed). A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 50V cover the majority of today’s applications. Features of this new generations of DC-DC converter include pulse-by-pulse current limit, hiccup mode for short circuit protection, voltage feedforward regulation, soft-start, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown.

The device is available in plastic dual in line, DIP-8 for standard assembly, and SO16W for SMD assembly.

Key Features

  • PROTECTION AGAINST FEEDBACK DISCONNECTION
  • INHIBIT FOR ZERO CURRENT CONSUMPTION
  • SOFT START FUNCTION
  • THERMAL SHUTDOWN
  • ZERO LOAD CURRENT OPERATION
  • VOLTAGE FEEDFORWARD
  • UP TO 2A STEP DOWN CONVERTER
  • PRECISE 3.3V (±1%) INTERNAL REFERENCE VOLTAGE
  • OPERATING INPUT VOLTAGE FROM 8V TO 55V
  • SWITCHING FREQUENCY ADJUSTABLE UP TO 300KHz
  • INTERNAL CURRENT LIMITING (PULSE-BYPULSE AND HICCUP MODE)
  • OUTPUT VOLTAGE ADJUSTABLE FROM 3.3V TO 50V
Product Specifications
DescriptionVersionSize
DS1309: 2A step down switching regulator9.2578 KB
Application Notes
DescriptionVersionSize
AN1061: Designing with L4978, 2A high efficiency DC-DC convertery9.2793 KB
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
L4978D013TRSO-16WTape And Reel1.3891000NECEAR99MALAYSIA
L4978DIP-8Tube1.3891000NECEAR99MALAYSIA
L4978DSO-16WTube1.3891000NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
L4978D013TRSO-16WIndustrialEcopack1md_y7-wspc-so-wspc-16-wspc-.30-wspc-large-wspc-jedec-wspc-ms-013_a7y7u751ba6_signed.pdf
md_y7-wspc-so-wspc-16-wspc-.xml
L4978DIP-8IndustrialEcopack2 (**)md_8w-wspc-pdip-wspc-08-wspc-.3-wspc-cu-wspc-.25-wspc-au-wspc-w_cl8w-wspc-u752ba6.pdf
md_8w-wspc-pdip-wspc-08-wspc-.xml
L4978DSO-16WIndustrialEcopack1md_y7-wspc-so-wspc-16-wspc-.30-wspc-large-wspc-jedec-wspc-ms-013_a7y7u751ba6_signed.pdf
md_y7-wspc-so-wspc-16-wspc-.xml
2A step down switching regulator L4978
circuit_diagram_5686_thumbnail.png L4978
Designing with L4978, 2A high efficiency DC-DC convertery L4978
ST1S03 alternative topology: Using a buck in a negative buck-boost configuration L5986
Very low drop voltage regulators with inhibit KFXX
md_8w-wspc-pdip-wspc-08-wspc-.3-wspc-cu-wspc-.25-wspc-au-wspc-w_cl8w-wspc-u752ba6.pdf L4978
md_8w-wspc-pdip-wspc-08-wspc-.xml L4978
md_y7-wspc-so-wspc-16-wspc-.30-wspc-large-wspc-jedec-wspc-ms-013_a7y7u751ba6_signed.pdf L4978
md_y7-wspc-so-wspc-16-wspc-.xml L4978