PX3511D
Advanced Synchronous Rectified Buck MOSFET Driver with Protection Features

Key Features

• Dual MOSFET Drives for Synchronous Rectified Bridge
• Pin-to-pin Compatible with ISL6596
• Advanced Adaptive Zero Shoot-Through Protection
• Body Diode Detection
• Auto-zero of rDS(ON) Conduction Offset Effect
• Adjustable Gate Voltage for Optimal Efficiency
• 36V Internal Bootstrap Schottky Diode
• Bootstrap Capacitor Overcharging Prevention
• Supports High Switching Frequency (up to 2MHz)
• 3A Sinking Current Capability
• Fast Rise/Fall Times and Low Propagation Delays
• Optimized for 3.3V PWM Input
• Three-State PWM Input for Output Stage Shutdown
• Three-State PWM Input Hysteresis for Applications With Power Sequencing Requirement
• Pre-POR Overvoltage Protection
• VCC Undervoltage Protection
• Expandable Bottom Copper Pad for Enhanced Heat Sinking
• Dual Flat No-Lead (DFN) Package
• Near Chip-Scale Package Footprint; Improves PCB Efficiency and Thinner in Profile
• Pb-Free Plus Anneal Available (RoHS Compliant)

Description

The PX3511D is high frequency MOSFET driver specifically designed to drive upper and lower power N-Channel MOSFETs in a synchronous rectified buck converter topology. This driver combined with the PX3511D Digital Multi-Phase Buck PWM controller and N-Channel MOSFETs forms a complete core-voltage regulator solution for advanced microprocessors.

The PX3511D drives both upper and lower gates over a range of 4.5V to 13.2V. This drive-voltage provides the flexibility necessary to optimize applications involving tradeoffs between gate charge and conduction losses.

An advanced adaptive zero shoot-through protection is integrated to prevent both the upper and lower MOSFETs from conducting simultaneously and to minimize the dead time. The PX3511D includes an overvoltage protection feature operational before VCC exceeds its turn-on threshold, at which the PHASE node is connected to the gate of the low side MOSFET (LGATE). The output voltage of the converter is then limited by the threshold of the low side MOSFET, which provides some protection to the microprocessor if the upper MOSFET(s) is shorted.

The PX3511D also features an input that recognizes a highimpedance state, working together with Intersil multi-phase PWM controllers to prevent negative transients on the controlled output voltage when operation is suspended. This feature eliminates the need for the schottky diode that may be utilized in a power system to protect the load from negative output voltage damage.

Applications

• Optimized for POL DC/DC Converters for IBA Systems
• Core Regulators for Intel® and AMD® Microprocessors
• High Current DC/DC Converters
• High Frequency and High Efficiency VRM and VRD