LT1616
600mA, 1.4MHz Step-Down
Switching Regulator
in SOT-23
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FEATURES
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DESCRIPTIO
The LT ®1616 is a current mode PWM step-down DC/DC
converter with internal 0.6A power switch, packaged in a
tiny 6-lead SOT-23. The wide input range of 3.6V to 25V
makes the LT1616 suitable for regulating a wide variety of
power sources, from 4-cell batteries and 5V logic rails to
unregulated wall transformers and lead-acid batteries. Its
high operating frequency allows the use of tiny, low cost
inductors and ceramic capacitors. With its internal compensation eliminating additional components, a complete
400mA step-down regulator fits onto 0.15 square inches
of PC board area.
Wide Input Range: 3.6V to 25V
5V at 400mA from 7V to 25V Input
3.3V at 400mA from 4.7V to 25V Input
Fixed Frequency 1.4MHz Operation
Uses Tiny Capacitors and Inductors
Internally Compensated
Low Shutdown Current: <1µA
Low VCESAT Switch: 220mV at 300mA
Tiny 6-Lead SOT-23 Package
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APPLICATIO S
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The constant frequency current mode PWM architecture
and stable operation with ceramic capacitors results in
low, predictable output ripple. Current limiting provides
protection against shorted outputs. The low current (<1µA)
shutdown provides complete output disconnect, enabling
easy power management in battery-powered systems.
Wall Transformer Regulation
Local Logic Supply Conversion:
12V to 5V
12V or 5V to 3.3V, 2.5V or 1.8V
Distributed Supply Regulation
Digital Cameras
Battery-Powered Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
3.3V Step-Down Converter
5
VIN
BOOST
LT1616
OFF ON
4
SHDN
GND
2
C1
1µF
SW
FB
3
D2
1
6
R1
16.5k
R2
10k
C1: TAIYO-YUDEN TMK316BJ105
C2: TAIYO-YUDEN JMK316BJ106ML
D1: ON SEMICONDUCTOR MBR0530
D2: 1N4148
L1: SUMIDA CR43-100
C3
0.01µF
D1
100
L1
10µH
90
VOUT
3.3V
300mA: VIN = 4.5V TO 25V
400mA: VIN = 4.7V TO 25V
C2
10µF
VIN = 5V
VIN = 12V
80
EFFICIENCY (%)
VIN
4.5V TO 25V
Efficiency
VIN = 20V
70
60
50
1616 TA01
40
30
0
100
200
300
400
LOAD CURRENT (mA)
500
1616 G02
1
