LT1766-5_15 Datasheet, PDF (1/30 Pages) Linear Technology – 5.5V to 60V 1.5A, 200kHz Step-Down Switching Regulator

LT1766/LT1766-5
5.5V to 60V 1.5A, 200kHz
Step-Down Switching Regulator
FEATURES
n _{Wide Input Range: 5.5V to 60V}
n _{1.5A Peak Switch Current}
n _{Constant 200kHz Switching Frequency}
n _{Saturating Switch Design: 0.2Ω}
n _{Peak Switch Current Rating Maintained Over}
Full Duty Cycle Range
n _{Low Effective Supply Current: 2.5mA}
n _{Low Shutdown Current: 25μA}
n _{1.2V Feedback Reference Voltage (LT1766)}
n _{5V Fixed Output (LT1766-5)}
n _{Easily Synchronizable}
n _{Cycle-by-Cycle Current Limiting}
n _{Small 16-Pin SSOP and Thermally Enhanced}
TSSOP Packages
APPLICATIONS
n _{High Voltage, Industrial and Automotive}
n _{Portable Computers}
n _{Battery-Powered Systems}
n _{Battery Chargers}
n _{Distributed Power Systems}
DESCRIPTION
The LT^®1766/LT1766-5 are 200kHz monolithic buck switch-
ing regulators that accept input voltages up to 60V. A high
efficiency 1.5A, 0.2Ω switch is included on the die along
with all the necessary oscillator, control and logic circuitry.
A current mode control architecture delivers fast transient
response and excellent loop stability.
Special design techniques and a new high voltage process
achieve high efficiency over a wide input range. Efficiency
is maintained over a wide output current range by using the
output to bias the circuitry and by utilizing a supply boost
capacitor to saturate the power switch. Patented circuitry
maintains peak switch current over the full duty cycle range.
A shutdown pin reduces supply current to 25μA and the
device can be externally synchronized from 228kHz to
700kHz with logic-level inputs.
The LT1766/LT1766-5 are available in a 16-pin fused-lead
SSOP package or a TSSOP package with exposed backside
for improved thermal performance.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents, including 6498466, 6531909.
TYPICAL APPLICATION
V_IN*
5.5V TO 60V
5V Buck Converter
6
BOOST
2.2μF^†
4
V_IN
2
SW
100V
CERAMIC
LT1766
15
OFF ON
SHDN
10
BIAS
14
SYNC
12
FB
GND
V_C
1, 8, 9, 16 11
1N4148W
0.33μF
47μH
10MQ060N ₊
15.4k
4.99k
V_OUT
5V
1A
100μF 10V
SOLID
TANTALUM
2.2k
0.022μF
220pF
1766 TA01
*FOR INPUT VOLTAGES BELOW 7.5V, SOME RESTRICTIONS MAY APPLY
†_{TDK C4532X7R2A225K}
Efficiency vs Load Current
100
V_OUT = 5V
L = 47μH
90
V_IN = 12V
V_IN = 42V
80
70
60
50
0
0.25 0.50 0.75 1.00 1.25
LOAD CURRENT (A)
1766 TA02
1766fc
1