The ISL6420BMAEP simplifies the implementation of a complete control and protection scheme for a highperformance DC/DC buck converter. It is designed to drive N-Channel MOSFETs in a synchronous rectified buck topology, the ISL6420BMAEP 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.

The ISL6420BMAEP 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 ±2.0% 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 ISL6420BMAEP 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 r_DS(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.

Device Information
The specifications for an Enhanced Product (EP) device are defined in a Vendor Item Drawing (VID), which is controlled by the Defense Supply Center in Columbus (DSCC). "Hotlinks" to the applicable VID and other supporting application information are provided on our website.

• Specifications per DSCC VID V62/07640
• Full Mil-Temp Electrical Performance from -55°C to +125°C
• Controlled Baseline with One Wafer Fabrication Site and One Assembly/Test Site
• Full Homogeneous Lot Processing in Wafer Fab
• No Combination of Wafer Fabrication Lots in Assembly
• Full Traceability Through Assembly and Test by Date/Trace Code Assignment
• Enhanced Process Change Notification
• Enhanced Obsolescence Management
• Eliminates Need for Up-Screening a COTS Component
• Operates from 4.5V thru 5.5V and 5.6V thru 28V Inputs
• Excellent Output Voltage Regulation
  • 0.6V Internal Reference
  • ±2.0% Reference Accuracy Over Line and Temperature
• 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 r_DS(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

• Power Supplies for Microprocessors/ASICs
  • DSP and Core Processors
  • DDR SDRAM Bus Termination
• Distributed Power Systems
• Externally Referenced Buck Converters