DATASHEET ISL6525 FN4998 Rev 3.00 Buck and Synchronous-Rectifier Pulse-Width Modulator (PWM) Controller Dec 27, 2004 The ISL6525 provides complete control and protection for a Features DC-DC converter optimized for high-performance Drives Two N-Channel MOSFETs microprocessor applications. It is designed to drive two N Channel MOSFETs in a synchronous-rectified buck Operates From +5V or +12V Input topology. The ISL6525 integrates all of the control, output Simple Single-Loop Control Design adjustment, monitoring and protection functions into a single - Voltage-Mode PWM Control package. A programmable delay time for the PGOOD signal makes it especially suitable for the VTT regulation in Fast Transient Response VRM8.5 applications. - High-Bandwidth Error Amplifier - Full 0% to 100% Duty Ratio The output voltage of the converter can be precisely regulated to as low as 1.20V, with a maximum tolerance of Excellent Output Voltage Regulation 1% over temperature and line voltage variations. - 1.20V Internal Reference - 1% Over Line Voltage and Temperature The ISL6525 provides simple, single feedback loop, voltage- mode control with fast transient response. It includes a Programmable delay for PGOOD signal 200kHz free-running triangle-wave oscillator that is Over-Current Fault Monitor adjustable from below 50kHz to over 1MHz. The error - Does Not Require Extra Current Sensing Element amplifier features a 15MHz gain-bandwidth product and - Uses MOSFETs r DS(ON) 6V/ s slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty ratio Small Converter Size ranges from 0% to 100%. - Constant Frequency Operation - 200kHz Free-Running Oscillator Programmable from The ISL6525 protects against over-current conditions by 50kHz to Over 1MHz inhibiting PWM operation. The ISL6525 monitors the current by using the r of the upper MOSFET which eliminates DS(ON) 14 Pin, SOIC Package the need for a current sensing resistor. Pb-Free Available (RoHS Compliant) Ordering Information Applications TEMP. PKG. o Power Supply for Various Microprocessors PART NUMBER RANGE ( C) PACKAGE DWG. VTT Regulation for VRM8.5 ISL6525CB 0 to 70 14 Ld SOIC M14.15 High-Power 5V to 3.xV DC-DC Regulators ISL6525CBZ 0 to 70 14 Ld SOIC M14.15 (See Note) (Pb-free) Low-Voltage Distributed Power Supplies *Add -T suffix to part number for tape and reel packaging. Pinout NOTE: Intersil Pb-free products employ special Pb-free material ISL6525 sets molding compounds/die attach materials and 100% matte tin (SOIC) plate termination finish, which are RoHS compliant and compatible TOP VIEW 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. RT 14 1 DELAY 13 OCSET 2 VCC SS 3 12 LGATE COMP 11 4 PGND 10 FB 5 BOOT 9 GND 6 UGATE PGOOD 8 7 PHASE FN4998Rev 3.00 Page 1 of 11 Dec 27, 2004ISL6525 Typical Application 12V +5V OR +12V VCC OCSET SS MONITOR AND PROTECTION BOOT RT OSC UGATE PHASE ISL6525 +V O REF PVCC +12V LGATE - + + FB PGND - COMP GND Block Diagram VCC POWER-ON 110% RESET (POR) + DELAY - PGOOD 90% VCC 10 A + - 10 A SOFT- SS + START - OCSET OVER- CURRENT BOOT 200 A 4V UGATE REFERENCE PHASE PWM COMPARATOR DACOUT GATE INHIBIT + CONTROL + - - LOGIC PWM ERROR AMP LGATE FB PGND COMP GND OSCILLATOR RT FN4998 Rev 3.00 Page 2 of 11 Dec 27, 2004