LTC4447 Datasheet, PDF (1/12 Pages) Linear Technology – High Speed Synchronous N-Channel MOSFET Driver

FEATURES
■ _{Integrated Schottky Diode}
■ _{4V to 6.5V VCC Operating Voltage}
■ _{38V Maximum Input Supply Voltage}
■ _{Adaptive Shoot-Through Protection}
■ _{Rail-to-Rail Output Drivers}
■ _{3.2A Peak Pull-Up Current}
■ _{4.5A Peak Pull-Down Current}
■ _{8ns TG Risetime Driving 3000pF Load}
■ _{7ns TG Falltime Driving 3000pF Load}
■ _{Separate Supply to Match PWM Controller}
■ _{Drives Dual N-Channel MOSFETs}
■ _{Undervoltage Lockout}
■ _{Low Profile (0.75mm) 3mm × 3mm DFN Package}
APPLICATIONS
■ _{Distributed Power Architectures}
■ _{High Density Power Modules}
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All
other trademarks are the property of their respective owners.
LTC4447
High Speed Synchronous
N-Channel MOSFET Driver
DESCRIPTION
The LTC^®4447 is a high frequency gate driver with integrat-
ed bootstrap Schottky diode that is designed to drive two
N-Channel MOSFETs in a synchronous DC/DC converter.
The powerful rail-to-rail driver capability reduces switching
losses in MOSFETs with high gate capacitance.
The LTC4447 features a separate supply for the input logic
to match the signal swing of the controller IC. If the input
signal is not being driven, the LTC4447 activates a shut-
down mode that turns off both external MOSFETs. The input
logic signal is internally level-shifted to the bootstrapped
supply, which functions at up to 42V above ground. The
Schottky diode required for the bootstrapped supply is
integrated to simplify layout and reduce parts count.
The LTC4447 contains undervoltage lockout circuits on
both the driver and logic supplies that turn off the external
MOSFETs when an undervoltage condition is present. An
adaptive shoot-through protection feature is also built-in
to prevent the power loss resulting from MOSFET cross-
conduction current.
The LTC4447 is available in the 3mm × 3mm DFN
package.
TYPICAL APPLICATION
Synchronous Buck Converter Driver
V_CC
4V TO 6.5V
PWM
V_CC
V_LOGIC
BOOST
LTC4447 _TG
TS
IN
BG
GND
V_IN
TO 38V
V_OUT
4447 TA01a
LTC4447 Driving 3000pF Capacitive Loads
INPUT (IN)
5V/DIV
TOP GATE
(TG - TS)
5V/DIV
BOTTOM GATE
(BG) 5V/DIV
10ns/DIV
4447 TA01b
4447f
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