ISL6620 Datasheet, PDF (1/10 Pages) Intersil Corporation – VR11.1 Compatible Synchronous Rectified Buck MOSFET Drivers

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Data Sheet
VR11.1 Compatible Synchronous
Rectified Buck MOSFET Drivers
The ISL6620, ISL6620A is a high frequency MOSFET driver
designed to drive upper and lower power N-Channel
MOSFETs in a synchronous rectified buck converter topology.
The advanced PWM protocol of ISL6620, ISL6620A is
specifically designed to work with Intersil VR11.1 controllers
and combined with N-Channel MOSFETs, form a complete
core-voltage regulator solution for advanced microprocessors.
When ISL6620, ISL6620A detects a PSI protocol sent by an
Intersil VR11.1 controller, it activates Diode Emulation (DE)
operation; otherwise, it operates in normal Continuous
Conduction Mode (CCM) PWM mode.
The IC is biased by a single low voltage supply (5V),
minimizing driving losses in high MOSFET gate capacitance
and high switching frequency applications. Each driver is
capable of driving a 3nF load with less than 10ns rise/fall time.
Bootstrapping of the upper gate driver is implemented via an
internal low forward drop diode, reducing implementation cost,
complexity, and allowing the use of higher performance, cost
effective N-Channel MOSFETs.
To further enhance light load efficiency, ISL6620, ISL6620A
enables diode emulation operation during PSI mode. This
allows Discontinuous Conduction Mode (DCM) by detecting
when the inductor current reaches zero and subsequently
turning off the low side MOSFET to prevent it from sinking
current.
An advanced adaptive shoot-through protection is integrated
to prevent both the upper and lower MOSFETs from
conducting simultaneously and to minimize dead time. The
ISL6620, ISL6620A has a 20kΩ integrated high-side
gate-to-source resistor to prevent self turn-on due to high
input bus dV/dt.
ISL6620, ISL6620A
April 25, 2008
FN6494.0
Features
• Dual MOSFET Drives for Synchronous Rectified Bridge
• Advanced Adaptive Zero Shoot-Through Protection
• 36V Internal Bootstrap Schottky Diode
• Advanced PWM Protocol (Patent Pending) to Support PSI
Mode, Diode Emulation, Three-State Operation
• Diode Emulation For Enhanced Light Load Efficiency
• Bootstrap Capacitor Overcharging Prevention
• Supports High Switching Frequency
- 4A Sinking Current Capability
- Fast Rise/Fall Times and Low Propagation Delays
• VCC Undervoltage Protection
• Enable Input and Power-On Reset
• Expandable Bottom Copper Pad for Enhanced Heat
Sinking
• DFN Package:
- Compliant to JEDEC PUB95 MO-220
DFN - Dual Flat No Leads - Package Outline
- Near Chip Scale Package Footprint, which Improves
PCB Efficiency and has a Thinner Profile
• Pb-Free (RoHS Compliant)
Applications
• High Light Load Efficiency Voltage Regulators
• Core Regulators for Advanced Microprocessors
• High Current DC/DC Converters
• High Frequency and High Efficiency VRM and VRD
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
• Technical Brief TB417 “Designing Stable Compensation
Networks for Single Phase Voltage Mode Buck
Regulators” for Power Train Design, Layout Guidelines,
and Feedback Compensation Design
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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