The ISL6227 dual PWM controller delivers high efficiency precision voltage regulation from two synchronous buck DC/DC converters. It was designed especially to provide power regulation for DDR memory, chipsets, graphics and other system electronics in Notebook PCs. The ISL6227's wide input voltage range capability allows for voltage conversion directly from AC/DC adaptor or Li-Ion battery pack. Automatic mode transition of constant-frequency synchronous rectification at heavy load, and hysteretic (HYS) diode-emulation at light load, assure high efficiency over a wide range of conditions. The HYS mode of operation can be disabled separately on each PWM converter if constant-frequency continuous-conduction operation is desired for all load levels. Efficiency is further enhanced by using the lower MOSFET rDS(ON) as the current sense element. Voltage-feed-forward ramp modulation, current mode control, and internal feedback compensation provide fast response to input voltage and load transients. Input current ripple is minimized by channel-to-channel PWM phase shift of 0°, 90° or 180° (determined by input voltage and status of the DDR pin). The ISL6227 can control two independent output voltages adjustable from 0. 9V to 5. 5V, or by activating the DDR pin, transform into a complete DDR memory power supply solution. In DDR mode, CH2 output voltage VTT tracks CH1 output voltage VDDQ. CH2 output can both source and sink current, an essential power supply feature for DDR memory. The reference voltage VREF required by DDR memory is generated as well. In dual power supply applications the ISL6227 monitors the output voltage of both CH1 and CH2. An independent PGOOD (power good) signal is asserted for each channel after the soft-start sequence has completed, and the output voltage is within PGOOD window. In DDR mode CH1 generates the only PGOOD signal. Built-in overvoltage protection prevents the output from going above 115% of the set point by holding the lower MOSFET on and the upper MOSFET off. When the output voltage re-enters regulation, PGOOD will go HIGH and normal operation automatically resumes. Once the soft-start sequence has completed, undervoltage protection latches the offending channel off if the output drops below 75% of its set point value. Adjustable overcurrent protection (OCP) monitors the voltage drop across the rDS(ON) of the lower MOSFET. If more precise current-sensing is required, an external current sense resistor may be used.

Features

  • Provides Regulated Output Voltage in the Range 0.9V to 5.5V
  • Operates From an Input Battery Voltage Range of 5V to 28V or From 3.3V/5V System Rail
  • Complete DDR1 and DDR2 Memory Power Solution with VTT Tracking VDDQ/2 and a VDDQ/2 Buffered Reference Output
  • Flexible PWM or HYS Plus PWM Mode Selection with HYS Diode Emulation at Light Loads for Higher System Efficiency
  • rDS(ON) Current Sensing
  • Excellent Dynamic Response With Voltage Feed-Forward and Current Mode Control Accommodating Wide Range LC Filter Selections
  • Undervoltage Lock-Out on VCC Pin
  • Power-Good, Overcurrent, Overvoltage, Undervoltage Protection for Both Channels
  • Synchronized 300kHz PWM Operation in PWM Mode
  • Pb-Free Available (RoHS compliant)

Applications

  • Notebook PCs and Desknotes
  • Tablet PCs/Slates
  • Hand-Held Portable Instruments

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active QSOP Tube 480
Availability
Active QSOP Reel 2500
Availability
Active QFN Tube 60
Availability
Active QFN Reel 6000
Availability
Active QSOP Tube 480
Availability
Active QSOP Reel 2500
Availability
Active QFN Tube 60
Availability
Active QFN Reel 6000
Availability

Documentation & Downloads

Title Other Languages Type Format File Size Date
Datasheets & Errata
ISL6227 Datasheet Datasheet PDF 1.44 MB
User Guides & Manuals
ISL6227EVAL2Z User Guide Manual PDF 456 KB
ISL6227EVAL1 User Guide Manual PDF 669 KB
Application Notes & White Papers
Five Easy Steps to Create a Multi-Load Power Solution White Paper PDF 846 KB
How Green is Your Cloud? White Paper PDF 295 KB
AN1681: Grounding Techniques Application Note PDF 509 KB
AN1684: Nonideality of Ground Application Note PDF 397 KB
PCNs & PDNs
PCN14036 - Wafer fabrication Site Change for Listed Intersil Products - Palm Bay, Florida Product Change Notice PDF 294 KB
PCN13037 - Alternate Bond Wire Material for Assembly of the Listed Intersil QSOP Packaged Product Product Change Notice PDF 268 KB
PCN13025 - Alternate Bond Wire Material and Manufacturing Facilities for Assembly of the Listed Intersil DFN/QFN Packaged Products - Advanced Semiconductor Engineering (ASECL) - Chung-Li , Taiwan and STATS ChipPAC (SCM) - Kuala Lumpur, Mal Product Change Notice PDF 106 KB
PCN13009 - Alternate Bond Wire Material and Manufacturing Facilities for Assembly of the Listed Intersil DFN/QFN Packaged Products - Advanced Semiconductor Engineering (ASECL) - Chung-Li (ASECL), Taiwan and STATS ChipPAC (SCM) - Kuala Lump Product Change Notice PDF 173 KB
PCN10055 - Alternate Bond Wire Material for Assembly of the Listed Intersil DFN/QFN Packaged Products - STATS ChipPAC Malaysia Product Change Notice PDF 248 KB
Other
ISL6227 DDR Option iSim:PE Model Schematic SXSCH 223 KB
ISL6227 Non-DDR Application iSim:PE Model Schematic SXSCH 279 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