FD1505 Datasheet, PDF (1/2 Pages) Fairchild Semiconductor – Synchronous Step-Down MOSFET Driver

September 2008
FD1505 — Synchronous Step-Down MOSFET Driver
1. Overview
1.1. Features
ƒ High-speed, High-current Drivers for Synchronous N-
Channel MOSFETs
ƒ Adaptive Dead-time Control Optimizes Efficiency
When Used with Digital-DC™ Controllers
ƒ Adjustable Gate Drive Voltage: 4.5V to 7.5V
ƒ Integrated 30V Bootstrap Schottky Diode
ƒ Capable of Driving ≥ 40A per Phase
ƒ Supports Switching Frequency up to 1.4MHz
ƒ >5A Sink Low-side Driver
ƒ High-side Driver
ƒ <10ns Rise/Fall Times, Low Propagation Delay
ƒ Adjustable Gate Drive Strength Optimizes Efficiency
for Different VIN, VOUT, IOUT, fSW, and MOSFET
Combinations
ƒ Internal Non-overlap Watchdog Prevents Shoot-
through Currents
ƒ RoHS Compliant, Pb-free
ƒ Exposed Pad 3 x 3mm DFN-10 Package
1.2. Applications
ƒ High-Efficiency, High-Current DC-DC Buck
Converters with Digital Control and PMBus™
ƒ Multi-Phase Digital DC-DC converters with Phase
Adding/Dropping
ƒ Power Train Modules
ƒ Synchronous Rectification for Secondary Side
Isolated Power Converters
IMPORTANT NOTE:
ƒ For additional information, please contact
[e-mail].
1.3. Description
The FD1505 is an integrated high-speed, high-current
N-channel MOSFET driver for synchronous step-down
DC-DC conversion applications. When used with
Digital-DC™ PWM controllers, the FD1505 enables
dynamically adaptive dead-time control that optimizes
efficiency under all operating conditions. A dual input
PWM configuration enables this efficiency optimization
while minimizing complexity within the driver.
Operating from a 4.5V to 7.5V input, the FD1505
combines a 5A, 0.5Ω low-side driver and a 3A, 0.8Ω
high-side driver to support high step-down buck
applications. A unique adjustable gate drive current
scheme allows the user to adjust the drive current on
both drivers to optimize performance for a wide range of
input/output voltages, load currents, power MOSFETs,
and switching frequencies up to 1.4MHz. An integrated
30V bootstrap Schottky diode is used to charge the
external bootstrap capacitor. An internal watchdog
circuit prevents excessive shoot-through currents and
protects the external MOSFET switches.
The FD1505 is specified over a wide -40°C to 125°C
junction temperature range and is available in an
exposed-pad, DFN-10 package.
HSEL
V_DD
PWMH
PWML
BST
GH
Level
shift
Shoot-
through
Protection
V_DD
SW
GL
FD1505
Figure 1.
GND LSEL
Block Diagram
© 2008 Fairchild Semiconductor Corporation
FD1505 • Rev. 1.3.1
www.fairchildsemi.com