The ISL8009A is a high efficiency, monolithic, synchronous step-down DC/DC regulator that can deliver up to 1. 5A continuous output current. It is optimized for generating low output voltages down to 0. 8V. The supply voltage range of 2. 7V to 5. 5V allows for the use of single Li+cell, three NiMH cells or a regulated 5V input. The ISL8009A uses current mode control architecture to deliver very low duty cycle operation at high frequency with fast transient response and excellent loop stability. It has flexible operation mode selection of forced PWM mode and automatic PFM/PWM with as low as 17µA quiescent current, achieving high power conversion efficiency under light load condition, hence maximizing battery life. High 1. 6MHz pulse-width modulation (PWM) switching frequency allows the use of small external components. The ISL8009A integrates a pair of low ON-resistance P-Channel and N-Channel internal MOSFETs to maximize efficiency and minimize external component count. The 100% duty-cycle operation allows less than 400mV dropout voltage at 1. 5A output current. The ISL8009A offers a 2ms Power-On-Reset (POR) timer at power-up. The timer output can be reset by RSI. When shutdown, ISL8009A discharges the output capacitor through a 100Ω resistor. Other features include internal digital soft-start, enable for power sequence, overcurrent protection, and thermal shutdown. The ISL8009A is offered in a 2mmx3mm 8 Ld DFN package with 1mm maximum height. The complete converter occupies less than 1cm2 area.


  • High Efficiency Synchronous Buck Regulator with up to 95% Efficiency
  • 2ms Reset Timer
  • 2.7V to 5.5V Supply Voltage
  • 3% Output Accuracy Over-Temperature/Load/Line
  • 1.5A Guaranteed Output Current
  • 17µA Quiescent Supply Current in PFM Mode
  • Selectable Forced PWM Mode and PFM Mode
  • Less Than 1µA Logic Controlled Shutdown Current
  • 90% Maximum Duty Cycle for Lowest Dropout at 1.5A
  • Internal Current Mode Compensation
  • Internal Digital Soft-Start
  • Peak Current Limiting, Short Circuit Protection
  • Over-Temperature Protection
  • Enable
  • Soft Discharge Disable
  • Small 8 Ld 2mmx3mm DFN
  • Pb-Free (RoHS Compliant)


  • DC/DC POL Modules
  • µC/µP, FPGA and DSP Power
  • Plug-in DC/DC Modules for Routers and Switchers
  • Portable Instruments
  • Test and Measurement Systems

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active DFN Reel 6000
Active DFN Reel 250
Active DFN Reel 1000

Documentation & Downloads

Title language Type Format File Size Date
Datasheets & Errata
ISL8009A Datasheet 日本語 Datasheet PDF 1.04 MB
User Guides & Manuals
ISL8009AEVAL1Z User Guide Manual PDF 467 KB
Application Notes & White Papers
Five Easy Steps to Create a Multi-Load Power Solution White Paper PDF 846 KB
AN9208: High Frequency Power Converters Application Note PDF 592 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB
AN9210: A New Pspice Subcircuit For The Power MOSFET Featuring Global Temperature Options Application Note PDF 650 KB
AN9209: A Spice-2 Subcircuit Representation For Power MOSFETs Using Empirical Methods Application Note PDF 387 KB
AN7244: Understanding Power MOSFETs Application Note PDF 349 KB
ISL8009A iSim:PE Model Schematic SXSCH 181 KB

Software & Tool Pages

Title Type Description Company
iSim:PE Offline Simulation Tool Simulator iSim Personal Edition (iSim:PE) speeds the design cycle and reduces risk early in any project, identifying parts that can be used in current as well as next-generation designs. Renesas

Boards & Kits

Part Number Title Type Company
ISL8009AEVAL1Z High-Efficiency Synchronous Buck Regulator Evaluation Board Evaluation Renesas