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DATASHEET

High Voltage Synchronous Rectified Buck MOSFET Driver

ISL95808

The ISL95808 is a high frequency, dual MOSFET driver with low

shutdown current, optimized to drive two N-Channel power

MOSFETs in a synchronous-rectified buck converter topology. It

is especially suited for mobile computing applications that

require high efficiency and excellent thermal performance. The

driver, combined with an Intersil multiphase Buck PWM

controller, forms a complete single-stage core-voltage

regulator solution for advanced mobile microprocessors.

The ISL95808 features a 4A typical sinking current for the

lower gate driver. This current is capable of holding the lower

MOSFET gate off during the rising edge of the phase node. This

prevents shoot-through power loss caused by the high dv/dt of

phase voltages. The operating voltage matches the 30V

breakdown voltage of the MOSFETs commonly used in mobile

computer power supplies.

The ISL95808 also features a three-state PWM input. This

PWM input, working together with Intersil’s multiphase PWM

controllers, will prevent negative voltage output during CPU

shutdown. This feature eliminates a protective Schottky diode

usually seen in microprocessor power systems.

MOSFET gates can be efficiently switched up to 2MHz using

the ISL95808. Each driver is capable of driving a 3000pF load

with propagation delays of 8ns and transition times under

10ns. Bootstrapping is implemented with an internal Schottky

diode. This reduces system cost and complexity, while allowing

for the use of higher performance MOSFETs. Adaptive

shoot--through protection is integrated to prevent both

MOSFETs from conducting simultaneously.

A diode emulation feature is integrated in the ISL95808 to

enhance converter efficiency at light load conditions. This

feature also allows for monotonic start-up into prebiased

outputs. When diode emulation is enabled, the driver will allow

discontinuous conduction mode by detecting when the

inductor current reaches zero and subsequently turning off the

low-side MOSFET gate.

The ISL95808 also features very low shutdown supply current

(5V, 3µA) to ensure the low power consumption.

Features

• Dual MOSFET drivers for synchronous rectified bridge

• Adaptive shoot-through protection

•0.5Ω ON-resistance and 4A sink current capability

• Supports high switching frequency up to 2MHz

- Fast output rise and fall time

- Low propagation delay

• Three-state PWM input for power stage shutdown

• Internal bootstrap Schottky diode

• Low shutdown supply current (5V, 3µA)

• Diode emulation for enhanced light-load efficiency and

prebiased start-up applications

• VCC POR (power-on-reset) feature integrated

• Low three-state shutdown holdoff time (typical 160ns)

•DFN package

• Pb-free (RoHS compliant)

Applications

• Core voltage supplies for Intel® and AMD™ mobile

microprocessors

• High frequency low profile DC/DC converters

• High current low output voltage DC/DC converters

• High input voltage DC/DC converters

Related Literature

• TB389, “PCB Land Pattern Design and Surface Mount

Guidelines for MLFP Packages”

• TB447, “Guidelines for Preventing Boot-to-Phase Stress on

Half-Bridge MOSFET Driver ICs”

VCC

PWM

10kΩ

CONTROL

LOGIC

SHOOT-

THROUGH

PROTECTION

BOOT

UGATE

PHASE

LGATE

GND

VCC

FCCM

THERMAL PAD

FIGURE 1. BLOCK DIAGRAM

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.

All other trademarks mentioned are the property of their respective owners.

June 29, 2015

FN8689.1