LT1936
1.4A, 500kHz Step-Down
Switching Regulator
FEATURES
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DESCRIPTION
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 in.
put 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 unregulated wall adapters. Its high operating frequency allows the
use of small, low cost inductors and ceramic capacitors,
resulting in low, predictable output ripple.
Cycle-by-cycle current limit, frequency foldback and
thermal 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 minimized by using internal compensation. The
low current (<2μA) shutdown mode enables easy power
management in battery-powered systems.
APPLICATIONS
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Automotive Battery Regulation
Industrial Control Supplies
Unregulated Wall Adapters
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
3.3V Step-Down Converter
Efficiency
95
VIN
4.5V TO 36V
SHDN
ON OFF
4.7μF
BOOST
SW
10μH
LT1936
VOUT
3.3V
1.2A
17.4k
COMP
VC
FB
GND
10k
VOUT = 5V
90
0.22μF
22μF
EFFICIENCY (%)
VIN
VIN = 12V
85
VOUT = 3.3V
80
75
70
1936 TA01a
65
0
0.5
1
LOAD CURRENT (A)
1.5
1936 TA01b
1936fd
1
