Advanced Single Synchronous Buck Pulse-Width Modulation (PWM) Controller

The ISL6420B 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 ISL6420B 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.

Features

• Operates From:

- 4.5V to 5.5V Input

- 5.5V to 28V Input

• 0.6V Internal Reference Voltage

- ±2.0 Reference Accuracy

• 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 MO-220

QFN -Quad Flat No Leads - Product Outline

- QFN Near Chip Scale Package Footprint; Improves

PCB Efficiency, Thinner in Profile

• Pb-Free (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