DATASHEET ISL6420 FN9151 Rev 5.00 Advanced Single Synchronous Buck Pulse-Width Modulation (PWM) Controller Feb 13, 2008 The ISL6420 makes simple work out of implementing a Features complete control and protection scheme for a high- Operates from 4.5V to 16V Input performance DC/DC buck converter. Designed to drive N-channel MOSFETs in a synchronous rectified buck 0.6V Internal Reference Voltage topology, the ISL6420 integrates control, output adjustment, - 1.0% Reference Voltage Accuracy monitoring and protection functions into a single package. Resistor-Selectable Switching Frequency Additionally, the IC features an external reference voltage - 100kHz to 1.4MHz tracking mode for externally referenced buck converter Voltage Margining and External Reference Tracking applications and DDR termination supplies, as well as a Modes voltage margining mode for system testing in networking DC/DC converter applications. Output Can Sink or Source Current The ISL6420 provides simple, single feedback loop, voltage Lossless, Programmable Overcurrent Protection mode control with fast transient response. The output - Uses Upper MOSFETs r DS(ON) voltage of the converter can be precisely regulated to as low Programmable Soft-Start as 0.6V. Drives N-Channel MOSFETs The operating frequency is fully adjustable from 100kHz to Simple Single-Loop Control Design 1.4MHz. High frequency operation offers cost and space - Voltage-Mode PWM Control savings. Fast Transient Response The error amplifier features a 15MHz gain-bandwidth - High-Bandwidth Error Amplifier product and 6V/s slew rate that enables high converter bandwidth for fast transient response. The PWM duty cycle - Full 0% to 100% Duty Cycle ranges from 0% to 100% in transient conditions. Selecting Extensive Circuit Protection Functions the capacitor value from the ENSS pin to ground sets a fully - PGOOD, overvoltage, overcurrent, Shutdown adjustable PWM soft-start. Pulling the ENSS pin LOW QFN (4x4) Package disables the controller. - QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad The ISL6420 monitors the output voltage and generates a Flat No Leads - Product Outline PGOOD (power good) signal when soft-start sequence is - QFN Near Chip Scale Package Footprint Improves complete and the output is within regulation. A built-in PCB Efficiency, Thinner in Profile overvoltage protection circuit prevents the output voltage Also Available in QSOP Package from going above typically 115% of the set point. Protection from overcurrent conditions is provided by monitoring the Pb-Free Available (RoHS Compliant) r of the upper MOSFET to inhibit the PWM operation DS(ON) appropriately. This approach simplifies the implementation Applications and improves efficiency by eliminating the need for a current Power Supplies for Microprocessors/ASICs sensing resistor. - 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 FN9151 Rev 5.00 Page 1 of 20 Feb 13, 2008ISL6420 Pinouts ISL6420 ISL6420 (20 LD QFN) (20 LD QSOP) TOP VIEW TOP VIEW 1 CDEL 20 PGOOD PGND 2 19 ENSS LGATE 3 18 COMP 20 19 18 17 16 PVCC 4 17 FB GPIO2 1 15 PGND PHASE 5 RT 16 GPIO1/REFIN 2 14 CDEL UGATE 6 15 SGND BOOT 7 14 VIN OCSET 3 13 PGOOD GPIO2 8 13 VCC5 REFOUT 4 12 ENSS GPIO1/REFIN 9 12 VMSET/MODE OCSET 10 11 REFOUT VMSET/MODE 5 11 COMP 678 9 10 Ordering Information TEMP. PKG. PART NUMBER PART MARKING RANGE (C) PACKAGE DWG. ISL6420IR ISL 6420IRZ -40 to +85 20 Ld 4x4 QFN L20.4x4 ISL6420IR-T* ISL 6420IRZ 20 Ld 4x4 QFN Tape and Reel L20.4x4 ISL6420IRZ (Note) 64 20IRZ -40 to +85 20 Ld 4x4 QFN (Pb-free) L20.4x4 ISL6420IRZ-T* (Note) 64 20IRZ 20 Ld 4x4 QFN Tape and Reel (Pb-free) L20.4x4 ISL6420IRZ-TK* (Note) 64 20IRZ 20 Ld 4x4 QFN Tape and Reel (Pb-free) L20.4x4 ISL6420IA ISL 6420IA -40 to +85 20 Ld QSOP M20.15 ISL6420IA-TK* ISL 6420IA 20 Ld QSOP Tape and Reel M20.15 ISL6420IAZ (Note) ISL 6420IAZ -40 to +85 20 Ld QSOP (Pb-free) M20.15 ISL6420IAZ-TK* (Note) ISL 6420IAZ 20 Ld QSOP Tape and Reel (Pb-free) M20.15 *Please refer to TB347 for details on reel specifications. NOTE: 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. FN9151 Rev 5.00 Page 2 of 20 Feb 13, 2008 VCC5 BOOT VIN UGATE SGND PHASE RT PVCC FB LGATE