LTC3722-2_15 Datasheet, PDF (1/28 Pages) Linear Technology – Synchronous Dual Mode Phase Modulated Full Bridge Controllers

FEATURES
n _{Adaptive or Manual Delay Control for Zero Voltage}
Switching Operation
n _{Adjustable Synchronous Rectification Timing for}
Highest Efficiency
n _{Adjustable Maximum ZVS Delay}
n _{Adjustable System Undervoltage Lockout Hysteresis}
n _{Programmable Leading Edge Blanking}
n _{Very Low Start-Up and Quiescent Currents}
n _{Current Mode (LTC3722-1) or Voltage Mode}
(LTC3722-2) Operation
n _{Programmable Slope Compensation}
n _{VCC UVLO and 25mA Shunt Regulator}
n _{50mA Output Drivers}
n _{Soft-Start, Cycle-by-Cycle Current Limiting and}
Hiccup Mode Short-Circuit Protection
n _{5V, 15mA Low Dropout Regulator}
n _{24-Pin Surface Mount GN Package}
APPLICATIONS
n _{Telecommunications, Infrastructure Power Systems}
n _{Distributed Power Architectures}
n _{Server Power Supplies}
LTC3722-1/LTC3722-2
Synchronous Dual Mode
Phase Modulated
Full Bridge Controllers
DESCRIPTION
The LTC^®3722-1/LTC3722-2 phase-shift PWM controllers
provide all of the control and protection functions neces-
sary to implement a high efficiency, zero voltage switched
(ZVS), full bridge power converter. Adaptive ZVS circuitry
delays the turn-on signals for each MOSFET independent
of internal and external component tolerances. Manual
delay set mode enables secondary side control operation
or direct control of switch turn-on delays.
The LTC3722-1/LTC3722-2 feature adjustable synchron-
ous rectifier timing for optimal efficiency. A UVLO program
input provides accurate system turn-on and turn-off
voltages. The LTC3722-1 features peak current mode
control with programmable slope compensation and
leading edge blanking, while the LTC3722-2 employs
voltage mode control.
The LTC3722-1/LTC3722-2 feature extremely low operating
and start-up currents. Both devices include a full range of
protection features and are available in the 24-pin surface
mount GN package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
DirectSense is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATION
V_IN
36V TO
72V
C_IN
R1
U1
U2
MA MC
T1
LTC3722
MB MD
L1
V_OUT
12V
L2
C_OUT
RCS
T2
C1
U1, U2: LTC4440 GATE DRIVER
U3: LTC3901 GATE DRIVER
ME
U3
MF
372212 TA01a
12V_OUT, 240W Converter Efficiency
95
36V_IN
90
48V_IN
72V_IN
85
80
75
0 2 4 6 8 10 12 14 16 18 20
CURRENT (A)
372212 TA01b
For more information www.linear.com/LTC3722
372212fb
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