LT1936
1.4A, 500kHz Step-Down
Switching Regulator
FEATURES
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DESCRIPTIO
Wide Input Range: 3.6V to 36V
Short-Circuit Protected Over Full Input Range
1.9A Guaranteed Minimum Switch Current
5V at 1.4A from 10V to 36V Input
3.3V at 1.4A from 7V to 36V Input
5V at 1.2A from 6.3V to 36V Input
3.3V at 1.2A from 4.5V to 36V Input
Output Adjustable Down to 1.20V
500kHz Fixed Frequency Operation
Soft-Start
Uses Small Ceramic Capacitors
Internal or External Compensation
Low Shutdown Current: <2µA
Thermally Enhanced 8-Lead MSOP Package
The LT
®
1936 is a current mode PWM step-down DC/DC
converter with an internal 1.9A power switch, packaged in
a tiny, thermally enhanced 8-lead MSOP. The wide input
range of 3.6V to 36V makes the LT1936 suitable for
regulating power from a wide variety of sources, including
automotive batteries, 24V industrial supplies and unregu-
lated wall adapters. Its high operating frequency allows
the use of small, low cost inductors and ceramic capaci-
tors, resulting in low, predictable output ripple.
Cycle-by-cycle current limit, frequency foldback and ther-
mal shutdown provide protection against shorted outputs,
and soft-start eliminates input current surge during start-
up. Transient response can be optimized by using external
compensation components, or board space can be mini-
mized by using internal compensation. The low current
(<2µA) shutdown mode enables easy power management
in battery-powered systems.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
APPLICATIO S
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Automotive Battery Regulation
Industrial Control Supplies
Unregulated Wall Adapters
TYPICAL APPLICATIO
V
IN
4.5V TO 36V
V
IN
ON OFF
4.7µF
SHDN
LT1936
3.3V Step-Down Converter
95
0.22µF
10µH
V
IN
= 12V
V
OUT
= 5V
BOOST
SW
90
85
EFFICIENCY (%)
17.4k
COMP
V
C
FB
GND
10k
V
OUT
3.3V
1.2A
80
75
70
22µF
1936 TA01a
65
0
U
Efficiency
V
OUT
= 3.3V
0.5
1
LOAD CURRENT (A)
1.5
1936 TA01b
U
U
1936fa
1