Up to 1.5 A step down switching regulator

The L5973AD is a step down monolithic power switching regulator with a switch current limit of 2A so it is able to deliver more than 1.5 A DC current to the load depending on the application conditions.

The output voltage can be set from 1.235 V to 35 V. The high current level is also achieved thanks to an SO8 package with exposed frame, that allows to reduce the RthJA down to approximately 40 °C/W.

The device uses an internal P-Channel D-MOS transistor (with a typical of 200 mΩ) as switching element to avoid the use of bootstrap capacitor and guarantee high efficiency.

An internal oscillator fixes the switching frequency at 500 kHz to minimize the size of external components.

Having a minimum input voltage of 4 V only, it is particularly suitable for 5 V bus, available in all computer related applications.

Pulse by pulse current limit with the internal frequency modulation offers an effective constant current short circuit protection.

Key Features

  • Inhibit for zero current consumption
  • Internal current limiting
  • Protection against feedback disconnection
  • Synchronization
  • Thermal shutdown
  • Voltage feedforward
  • 500 kHz Internally fixed frequency
  • 2 A Internal switch
  • 3.3 V / (±2 %) reference voltage
  • Operating input voltage from 4 V to 36 V
  • Low dropout operation: 100 % duty cycle
  • Zero load current operation
  • Output voltage adjustable from 1.235 V to 35 V

Circuit Diagram

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Technical Documentation

Product Specifications
Description Version Size
DS3330 DS3330: 2 A switch step down switching regulator 9.3 483 KB
Application Notes
Description Version Size
AN2823 AN2823: Current source for LED driving based on the L5973AD 1.1 1 MB
AN1723 AN1723: Designing with L5973AD high efficiency DC-DC converter 4.0 1 MB
Design Notes & Tips
Description Version Size
DN0011 DN0011: ST1S03 alternative topology: Using a buck in a negative buck-boost configuration 1.1 359 KB

HW Model, CAD Libraries & SVD

HW Model, CAD Libraries & SVD
Description Version Size
X597X Pspice model 3 MB

Publications and Collaterals

Description Version Size
Brochure Power management guide 09.2017 3 MB
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
L5973ADTR PowerSO-8 Tape And Reel Active 0.991 1000 NEC EAR99 - MORE INFO DISTRIBUTOR AVAILABILITY

(*) 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**
L5973AD ActivePowerSO-8IndustrialEcopack2 0 0
L5973ADTR ActivePowerSO-8IndustrialEcopack2 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.