ISL6420A FN9169 PUB95 MO-220 1-888-INTERSIL ISL6420AIAZ 6420AIAZ ISL6420AIAZ-TK - Datasheet Archive

 

® Data Sheet October 13, 2005 FN9169.1 Advanced Single Synchronous Buck Pulse-Width Modulation (PWM) Controller Features The

 

ISL6420A ISL6420A ® Data Sheet October 13, 2005 FN9169 FN9169.1 Advanced Single Synchronous Buck Pulse-Width Modulation (PWM) Controller Features The ISL6420A ISL6420A simplifies the implementation of a complete control and protection scheme for a high-performance DC/DC buck converter. It is designed to drive N-channel MOSFETs in a synchronous rectified buck topology, the ISL6420A ISL6420A integrates control, output adjustment, monitoring and protection functions into a single package. Additionally, the IC features an external reference voltage tracking mode for externally referenced buck converter applications and DDR termination supplies, as well as a voltage margining mode for system testing in networking DC/DC converter applications. · Excellent Output Voltage Regulation - 0.6V Internal Reference - ±1.0% Reference Accuracy Over Line and Temperature The ISL6420A ISL6420A provides simple, single feedback loop, voltage mode control with fast transient response. The output voltage of the converter can be precisely regulated to as low as 0.6V, with a maximum tolerance of ±1.0% over temperature and line voltage variations. The operating frequency is fully adjustable from 100kHz to 1.4MHz. High frequency operation offers cost and space savings. The error amplifier features a 15MHz gain-bandwidth product and 6V/µs slew rate that enables high converter bandwidth for fast transient response. The PWM duty cycle ranges from 0% to 100% in transient conditions. Selecting the capacitor value from the ENSS pin to ground sets a fully adjustable PWM soft-start. Pulling the ENSS pin LOW disables the controller. The ISL6420A ISL6420A monitors the output voltage and generates a PGOOD (power good) signal when soft-start sequence is complete and the output is within regulation. A built-in overvoltage protection circuit prevents the output voltage from going above typically 115% of the set point. Protection from overcurrent conditions is provided by monitoring the rDS(ON) of the upper MOSFET to inhibit the PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sensing resistor. · Operates from 4.5V to 28V Input · Resistor-Selectable Switching Frequency - 100kHz to 1.4MHz · Voltage Margining and External Reference Tracking Modes · Output Can Sink or Source Current · Lossless, Programmable Overcurrent Protection - Uses Upper MOSFET's rDS(ON) · Programmable Soft-Start · Drives N-Channel MOSFETs · Simple Single-Loop Control Design - Voltage-Mode PWM Control · Fast Transient Response - High-Bandwidth Error Amplifier - Full 0% to 100% Duty Cycle · Extensive Circuit Protection Functions - PGOOD, Overvoltage, Overcurrent, Shutdown · Diode Emulation during Startup for Pre-Biased Load Applications · Offered in 20 Ld QFN and QSOP Packages · QFN (4x4) Package - QFN compliant to JEDEC PUB95 PUB95 MO-220 MO-220 QFN - Quad Flat No Leads - Product Outline - QFN Near Chip Scale Package Footprint; Improves PCB Efficiency, Thinner in Profile · Pb-Free Plus Anneal Available (RoHS Compliant) Applications · Power Supplies for Microprocessors/ASICs - Embedded Controllers - DSP and Core Processors - DDR SDRAM Bus Termination · Ethernet Routers and Switchers · High-Power DC/DC Regulators · Distributed DC/DC Power Architecture · Personal Computer Peripherals · Externally Referenced Buck Converters 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL6420A ISL6420A Ordering Information PART MARKING PART NUMBER TEMP. RANGE (°C) PKG. DWG. # PACKAGE ISL6420AIAZ ISL6420AIAZ (Note) 6420AIAZ 6420AIAZ -40 to +85 20 Ld QSOP (Pb-free) M20.15 ISL6420AIAZ-TK ISL6420AIAZ-TK (Note) 6420AIAZ 6420AIAZ -40 to +85 20 Ld QSOP (Pb-free) Tape and Reel M20.15 ISL6420AIRZ ISL6420AIRZ (Note) 6420AIRZ 6420AIRZ -40 to +85 20 Ld 4x4 QFN (Pb-free) L20.4x4 ISL6420AIRZ-TK ISL6420AIRZ-TK (Note) 6420AIRZ 6420AIRZ -40 to +85 20 Ld 4x4 QFN (Pb-free) Tape and Reel L20.4x4 NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are 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 STD-020. Pinouts UGATE PHASE PVCC LGATE ISL6420A ISL6420A (QSOP) TOP VIEW BOOT ISL6420A ISL6420A (QFN) TOP VIEW 20 19 18 17 16 CDEL 1 PGND 2 19 ENSS LGATE 3 18 COMP 20 PGOOD 15 PGND GPIO1/REFIN 2 14 CDEL OCSET 3 13 PGOOD REFOUT 4 12 ENSS 6 7 8 9 RT 17 FB 5 16 RT UGATE 6 15 SGND BOOT 7 14 VIN GPIO2 8 13 VCC5 9 12 VMSET/MODE 11 REFOUT FB OCSET 10 10 SGND 11 COMP VIN 5 VCC5 VMSET/MODE 4 GPIO1/REFIN 1 PVCC PHASE GPIO2 2 FN9169 FN9169.1 October 13, 2005 ISL6420A ISL6420A Functional Block Diagram VIN VCC5 OCSET SGND LDO OVERCURRENT COMP + OCFLT PHASE REFERENCE 0.6V SS + OVFLT UVFLT UGATE FAULT LOGIC PHASE ERROR AMP - FB BOOT + - COMP PHASE LOGIC PWM LOGIC PWM COMP PVCC GPIO1/REFIN LGATE RAMP GENERATOR GPIO2 REFOUT VOLTAGE MARGINING VMSET/MODE OV/UV VOLTAGE MONITOR FB PGND OVFLT PGOOD OSC EN/SS RT UVFLT ENSS CDEL Typical 5V Input DC/DC Application Schematic 5V C6 C1 C3 C2 PVCC VIN VCC5 D1 OCSET MONITOR AND PROTECTION ENSS Q1 PGOOD C8 C9 UGATE OSC R2 CDEL R1 BOOT RT C7 0.1µF C5 C4 L1 PHASE REF 3.3V SGND + + - FB R3 C11 COMP Q2 C10 PGND GPIO1/REFIN R6 R5 LGATE -+ + C12 REFOUT GPIO2 C13 R4 VMSET/MODE 3 FN9169 FN9169.1 October 13, 2005 ISL6420A ISL6420A Typical 12V Input DC/DC Application Schematic 12V C6 C1 C3 C2 PVCC VIN VCC5 D1 OCSET MONITOR AND PROTECTION ENSS Q1 PGOOD R2 C9 UGATE OSC L1 PHASE CDEL C8 R1 BOOT RT C7 C5 C4 REF 3.3V SGND R3 C11 C10 PGND COMP GPIO1/REFIN R6 C12 R5 Q2 LGATE -+ + + + - FB REFOUT GPIO2 C13 R4 VMSET/MODE Typical 5V Input DC/DC Application Schematic 5V C6 C1 C3 C2 VIN PVCC C4 D1 VCC5 OCSET MONITOR AND PROTECTION SS/EN Q1 CDEL R2 R1 BOOT RT C7 C5 C8 UGATE OSC L1 PHASE PGOOD REF 2.5V/1.25V SGND R3 C10 C11 LGATE -+ + + + - FB C9 PGND COMP R5 Q2 GPIO1/REFIN