DATASHEET ISL6540A FN6288 Rev 5.00 Single-Phase Buck PWM Controller with Integrated High Speed MOSFET Driver Oct 7, 2008 and Pre-Biased Load Capability The ISL6540A is an improved version of the ISL6540 Features single-phase voltage-mode PWM controller with input voltage VIN and Power Rail Operation from +3.3V to +20V feed-forward compensation to maintain a constant loop gain for Fast Transient Response - 0 to 100% Duty Cycle optimal transient response, especially for applications with a - 15MHz Bandwidth Error Amplifier with 6V/s Slew Rate wide input voltage range. Its integrated high speed - Voltage-Mode PWM Leading and Trailing-Edge synchronous rectified MOSFET drivers and other sophisticated Modulation Control features provide complete control and protection for a DC/DC - Input Voltage Feedforward Compensation converter with minimum external components, resulting in 2.9V to 5.5V High Speed 2A/4A MOSFET Gate Drivers minimum cost and less engineering design efforts. - Tri-state for Power Stage Shutdown The output voltage of the converter can be precisely regulated Internal Linear Regulator (LR) - 5.5V Bias from VIN with an internal reference voltage of 0.591V, and has an External LR Drive for Optimal Thermal Performance improved system tolerance of 0.68% over commercial Voltage Margining with Independently Adjustable Upper and temperature and line load variations. An external voltage can Lower Settings for System Stress Testing and Over Clocking be used in place of the internal reference for voltage Reference Voltage I/O for DDR/Tracking Applications tracking/DDR applications. Improved 0.591V Internal Reference with Buffered Output The ISL6540A has an internal linear regulator or external linear - 0.68%/1.0% Over Commercial/Industrial Range regulator drive options for applications with only a single supply Source and Sink Overcurrent Protections rail. The internal oscillator is adjustable from 250kHz to 2MHz. - Low-and High-Side MOSFET r Sensing DS(ON) The integrated voltage margining, programmable pre-biased Overvoltage and Undervoltage Protections soft-start, differential remote sensing amplifier, and Small Converter Size - QFN package programmable input voltage POR features enhance the Oscillator Programmable from 250kHz to 2MHz ISL6540A value. Differential Remote Voltage Sensing with Unity Gain Programmable Soft-Start with Pre-Biased Load Capability Pinout Power-Good Indication with Programmable Delay ISL6540A EN Input with Voltage Monitoring Capability (28 LD 5x5 QFN) TOP VIEW Pb-Free (RoHS Compliant) Applications Power Supply for some Microprocessors and GPUs 28 27 26 25 24 23 22 Wide and Narrow Input Voltage Range Buck Regulators VSEN+ 1 21 BOOT Point of Load Applications Low-Voltage and High Current Distributed Power Supplies VSEN- 2 20 UGATE Ordering Information REFOUT 3 19 PHASE GND PART TEMP. REFIN PGND 4 18 BOTTOM NUMBER* PART RANGE PACKAGE PKG. SIDE PAD SS 5 17 LGATE (Note) MARKING (C) (Pb-Free) DWG. ISL6540ACRZ* ISL6540 ACRZ 0 to +70 28 Ld 5x5 QFN L28.5x5 PVCC OFS+ 6 16 ISL6540AIRZ* ISL6540 AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5 LINDRV OFS- 7 15 ISL6540AIRZA* ISL6540 AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5 8 9 10 11 12 13 14 *Add -T suffix for tape and reel. Please refer to TB347 for details on reel specifications. These Intersil Pb-free plastic packaged products employ special Pb- free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. FN6288 Rev 5.00 Page 1 of 22 Oct 7, 2008 VCC VMON MARCTRL GND PG DLY FB PG COMP EN FS VFF LSOC VIN HSOCISL6540A FN6288 Rev 5.00 Page 2 of 22 Oct 7, 2008 Block Diagram VCC EN LIN DRV VIN POWER-ON REFERENCE RESET (POR) REFIN INTERNAL SERIES EXTERNAL SERIES V = 0.591 V REF LINEAR LINEAR DRIVER HSOC REFOUT 100A MAR CTRL OFS+ BOOT SOFT-START VOLTAGE AND SOURCE OCP MARGINING FAULT LOGIC OFS- UGATE OTA PWM PHASE SS COMP GATE CONTROL LOGIC FB EA COMP PVCC VCC OV/UV COMP OSCILLATOR 1.8V LGATE SOURCE OCP PGND PGOOD COMP VSEN+ GND G = -1 VSEN- GND G = 1 100A UNITY GAIN SINKING OCP DIFF AMP PG DLY VMON PG LSOC VFF FS