LT1616 Datasheet, PDF (1/16 Pages) Linear Technology – 600mA, 1.4MHz Step-Down Switching Regulator in SOT-23

FEATURES
s _{Wide Input Range: 3.6V to 25V}
s _{5V at 400mA from 7V to 25V Input}
s _{3.3V at 400mA from 4.7V to 25V Input}
s _{Fixed Frequency 1.4MHz Operation}
s _{Uses Tiny Capacitors and Inductors}
s _{Internally Compensated}
s _{Low Shutdown Current: <1µA}
s _{Low VCESAT Switch: 220mV at 300mA}
s _{Tiny 6-Lead SOT-23 Package}
U
APPLICATIO S
s _{Wall Transformer Regulation}
s _{Local Logic Supply Conversion:}
12V to 5V
12V or 5V to 3.3V, 2.5V or 1.8V
s _{Distributed Supply Regulation}
s _{Digital Cameras}
s _{Battery-Powered Equipment}
LT1616
600mA, 1.4MHz Step-Down
Switching Regulator
in SOT-23
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 com-
pensation eliminating additional components, a complete
400mA step-down regulator fits onto 0.15 square inches
of PC board area.
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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
3.3V Step-Down Converter
V_IN
4.5V TO 25V
OFF ON
5
V_IN
1
BOOST
LT1616
4
SHDN
6
SW
GND
FB _R1
2
3 ^16.5k
C1
R2
1µF
10k
D2
C3
L1
0.01µF _10µH
D1
C1: TAIYO-YUDEN TMK316BJ105
C2: TAIYO-YUDEN JMK316BJ106ML
D1: ON SEMICONDUCTOR MBR0530
D2: 1N4148
L1: SUMIDA CR43-100
V_OUT
3.3V
300mA: V_IN = 4.5V TO 25V
400mA: V_IN = 4.7V TO 25V
C2
10µF
1616 TA01
100
90
80
70
60
50
40
30
0
Efficiency
V_IN = 5V V_IN = 12V
V_IN = 20V
100 200 300 400 500
LOAD CURRENT (mA)
1616 G02
1