61 V 3 A asynchronous step-down switching regulator with adjustable current limitation

The L7987 device is a step-down monolithic switching regulator able to deliver up to 3 A DC. The output voltage adjustability ranges from 0.8 V to VIN. The wide input voltage range and the 100% duty cycle capability meet the fail safe specifications for industrial systems. The embedded switchover feature on the VBIASpin maximizes the efficiency at light load. The adjustable current limitation, designed to select the inductor RMS current accordingly with the nominal output current, and the high switching frequency capability make the size of the application compact. Pulse-by-pulse current sensing with digital frequency foldback implements an effective constant current protection over the different application conditions. The peak current foldback decreases the stress of the power components in heavy short-circuit condition. The PGOOD open collector output can also implement output voltage sequencing during the power-up phase. Multiple devices can be synchronized sharing the SYNCH pin to prevent beating noise in low noise applications like sensors with A/D conversion.

Key Features

  • 3 A DC output current
  • 4.5 V to 61 V operating input voltage
  • RDS,ON = 250 mΩ typ.
  • Adjustable fSW (250 kHz - 1.5 MHz)
  • Low IQ-SHD (11 μA typ. from VIN )
  • Low IQ (1 mA typ. - VIN 24 V - VOUT 3.3 V)
  • Output voltage adjustable from 0.8 V to VIN
  • Synchronization
  • Adjustable soft-start time
  • Adjustable current limitation
  • Low dropout operation (12 μs max.)
  • VBIAS improves efficiency at light load
  • PGOOD open collector output
  • Output voltage sequencing
  • Digital frequency foldback in short-circuit
  • Peak current foldback in short-circuit
  • Auto-recovery thermal shutdown


Technical Documentation

Product Specifications
Description Version Size
61 V 3 A asynchronous step-down switching regulator with adjustable current limitation 3.0 2 MB

HW Model, CAD Libraries & SVD

HW Model, CAD Libraries & SVD
Description Version Size
L7987 Pspice model 1.0 241 KB

Publications and Collaterals

Description Version Size
DC-DC converters 557 KB
Description Version Size
Brochure Power management guide 09.2017 3 MB

Tools and Software

Evaluation Tools
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eDesignSuite 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
L7987 HTSSOP16 Tube Active 1.25 1000 NEC EAR99 - 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**
L7987TR ActiveHTSSOP16IndustrialEcopack2 0 0
L7987 ActiveHTSSOP16IndustrialEcopack2 0 0

(**) 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.