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