LTC1922-1_15 Datasheet, PDF (1/24 Pages) Linear Technology – Synchronous Phase Modulated Full-Bridge Controller

LTC1922-1
Synchronous Phase
Modulated Full-Bridge Controller
FEATURES
DESCRIPTIO
s _{Adaptive DirectSense}^TM _{Zero Voltage Switching}
s _{Integrated Synchronous Rectification Control for}
Highest Efficiency
s _{Output Power Levels from 50W to Kilowatts}
s _{Very Low Start-Up and Quiescent Currents}
s _{Compatible with Voltage Mode and Current Mode}
Topologies
s _{Programmable Slope Compensation}
s _{Undervoltage Lockout Circuitry with 4.2V Hysteresis}
and Integrated 10.3V Shunt Regulator
s _{Fixed Frequency Operation to 1MHz}
s _{50mA Outputs for Bridge Drive and Secondary Side}
Synchronous Rectifiers
s _{Soft-Start, Cycle-by-Cycle Current Limiting and}
Hiccup Mode Short-Circuit Protection
s _{5V, 15mA Low Dropout Regulator}
s _{20-Pin PDIP and SSOP Packages}
U
APPLICATIO S
s _{Telecommunications, Infrastructure Power Systems}
s _{Distributed Power Architectures}
s _{Server Power Supplies}
s _{High Density Power Modules}
The LTC^®1922-1 phase shift PWM controller provides all
of the control and protection functions necessary to imple-
ment a high performance, zero voltage switched, phase
shift, full-bridge power converter with synchronous recti-
fication. The part is ideal for developing isolated, low
voltage, high current outputs from a high voltage input
source. The LTC1922-1 combines the benefits of the full-
bridge topology with fixed frequency, zero voltage switch-
ing operation (ZVS). Adaptive ZVS circuity controls the
turn-on signals for each MOSFET independent of internal
and external component tolerances for optimal perfor-
mance.
The LTC1922-1 also provides secondary side synchro-
nous rectifier control. The device uses peak current mode
control with programmable slope comp and leading edge
blanking.
The LTC1922-1 features extremely low operating and
start-up currents to simplify off-line start-up and bias
circuitry. The LTC1922-1 also includes a full range of
protection features and is available in 20-pin through hole
(N) and surface mount (G) packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
DirectSense is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
V_IN
48V
BIAS
SUPPLY
LTC1922-1
V_OUT
3.3V
ISOLATED
FEEDBACK
Efficiency
100
90
V_IN = 48V
80
V_IN = 36V
70
60
0
10
20
30
40
LOAD CURRENT (A)
1922 • TA01b
1922 TA01a
1