LT1933 Datasheet, PDF (1/16 Pages) Linear Technology – 600mA, 500kHz Step-Down Switching Regulator in SOT-23

FEATURES
■ _{Wide Input Range: 3.6V to 36V}
■ _{5V at 600mA from 16V to 36V Input}
■ _{3.3V at 600mA from 12V to 36V Input}
■ _{5V at 500mA from 6.3V to 36V Input}
■ _{3.3V at 500mA from 4.5V to 36V Input}
■ _{Fixed Frequency 500kHz Operation}
■ _{Uses Tiny Capacitors and Inductors}
■ _Soft-Start
■ _{Internally Compensated}
■ _{Low Shutdown Current: <2µA}
■ _{Output Adjustable Down to 1.25V}
■ _{Low Profile (1mm) SOT-23 (ThinSOT™) Package}
U
APPLICATIO S
■ _{Automotive Battery Regulation}
■ _{Industrial Control Supplies}
■ _{Wall Transformer Regulation}
■ _{Distributed Supply Regulation}
■ _{Battery-Powered Equipment}
LT1933
600mA, 500kHz Step-Down
Switching Regulator
in SOT-23
DESCRIPTIO
The LT^®1933 is a current mode PWM step-down DC/DC
converter with an internal 0.75A power switch, packaged
in a tiny 6-lead SOT-23. The wide input range of 3.6V to
36V makes the LT1933 suitable for regulating power from
a wide variety of sources, including unregulated wall
transformers, 24V industrial supplies and automotive
batteries. Its high operating frequency allows the use of
tiny, low cost inductors and ceramic capacitors, resulting
in low, predictable output ripple.
Cycle-by-cycle current limit provides protection against
shorted outputs, and soft-start eliminates input current
surge during start up. The low current (<2µA) shutdown
provides output disconnect, enabling easy power man-
agement in battery-powered systems.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
V_IN
4.5V TO 36V
OFF ON
3.3V Step-Down Converter
V_IN
BOOST
LT1933
SHDN
SW
GND
FB
16.5k
1N4148
0.1µF
22µH
MBRM140
2.2µF
10k
V_OUT
3.3V/500mA
22µF
1933 TA01a
Efficiency
95 _{VIN = 12V}
90
85
80
V_OUT = 5V
V_OUT = 3.3V
75
70
65
0 100 200 300 400 500 600
LOAD CURRENT (mA)
1933 TA01b
1933f
1