38 V 500 mA synchronous step-down switching regulator with 30 uA quiescent current

The L6985F is a step-down monolithic switching regulator able to deliver up to 0.5 A DC. The output voltage adjustability ranges from 0.85V to VIN. Thanks to the P-channel MOSFET high-side power element, the device features 100% of the duty cycle operation. The wide input voltage range meets the specification for the 5 V, 12 V and 24 V power supplies. The “Low Consumption Mode” (LCM) is designed for applications active during the idle mode, so it maximizes the efficiency at the light-load with the controlled output voltage ripple. The “Low Noise Mode” (LNM) makes the switching frequency constant overload current range, meeting the low noise application specification. The output voltage supervisor manages the reset phase for any digital load (μC, FPGA). The RST open collector output can also implement output voltage sequencing during the power-up phase. The synchronous rectification, designed for high efficiency at the medium - heavy load, and the high switching frequency capability make the size of the application compact. Pulse-by-pulse current sensing on both power elements implements effective constant current protection.

Key Features

  • 0.5 A DC output current
  • 4 V to 38 V operating input voltage
  • Low consumption mode or low noise mode
  • 30 μA IQ at light-load (LCM VOUT = 3.3 V)
  • Output voltage adjustable from 0.85 V to VIN
  • Adjustable fSW (250 kHz - 2 MHz)
  • Embedded output voltage supervisor
  • Synchronization
  • Adjustable soft-start time
  • Internal current limiting
  • Overvoltage protection
  • Output voltage sequencing
  • Peak current mode architecture
  • RDSON HS = 360 mΩ, RDSON LS = 150 mΩ
  • Thermal shutdown


Technical Documentation

Product Specifications
Description Version Size
DS11040 DS11040: 38 V, 500 mA synchronous step-down switching regulator with 30 µA quiescent current 2.0 1 MB

HW Model, CAD Libraries & SVD

HW Model, CAD Libraries & SVD
Description Version Size
A6985F Pspice model 270 KB
A6985F3V3 Spice model 268 KB
A6985F5V Spice model 267 KB

Publications and Collaterals

Description Version Size
Brochure Power management guide 09.2017 3 MB
Support & Community

Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
L6985FTR HTSSOP16 Tape And Reel Active 1.1 1000 NEC EAR99 MALAYSIA MORE INFO No availability reported, please contact our Sales office

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
L6985FTR ActiveHTSSOP16AutomotiveEcopack2
L6985F ActiveHTSSOP16AutomotiveEcopack2

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.