LT1613 Datasheet, PDF (1/12 Pages) Linear Technology – 1.4MHz, Single Cell DC/DC Converter in 5-Lead SOT-23

LT1613
1.4MHz, Single Cell DC/DC
Converter in 5-Lead SOT-23
FEATURES
s _{Uses Tiny Capacitors and Inductor}
s _{Internally Compensated}
s _{Fixed Frequency 1.4MHz Operation}
s _{Operates with VIN as Low as 1.1V}
s _{3V at 30mA from a Single Cell}
s _{5V at 200mA from 3.3V Input}
s _{15V at 60mA from Four Alkaline Cells}
s _{High Output Voltage: Up to 34V}
s _{Low Shutdown Current: <1µA}
s _{Low VCESAT Switch: 300mV at 300mA}
s _{Tiny 5-Lead SOT-23 Package}
U
APPLICATIO S
s _{Digital Cameras}
s _Pagers
s _{Cordless Phones}
s _{Battery Backup}
s _{LCD Bias}
s _{Medical Diagnostic Equipment}
s _{Local 5V or 12V Supply}
s _{External Modems}
s _{PC Cards}
TYPICAL APPLICATIO
V_IN
3.3V
+ _C1
15µF
SHDN
L1
4.7µH
D1
V_IN
SW
LT1613
SHDN
FB
GND
R1
37.4k ₊
V_OUT
5V
200mA
C2
22µF
R2
12.1k
L1: MURATA LQH3C4R7M24 OR SUMIDA CD43-4R7
C1: AVX TAJA156M010
C2: AVX TAJB226M006
D1: MBR0520
1613 TA01
Figure 1. 3.3V to 5V 200mA DC/DC Converter
DESCRIPTIO
The LT^®1613 is the industry’s first 5-lead SOT-23 current
mode DC/DC converter. Intended for small, low power
applications, it operates from an input voltage as low as
1.1V and switches at 1.4MHz, allowing the use of tiny, low
cost capacitors and inductors 2mm or less in height. Its
small size and high switching frequency enables the
complete DC/DC converter function to take up less than
0.2 square inches of PC board area. Multiple output power
supplies can now use a separate regulator for each output
voltage, replacing cumbersome quasi-regulated ap-
proaches using a single regulator and a custom trans-
former.
A constant frequency, internally compensated current
mode PWM architecture results in low, predictable output
noise that is easy to filter. The high voltage switch on the
LT1613 is rated at 36V, making the device ideal for boost
converters up to 34V as well as for Single-Ended Primary
Inductance Converter (SEPIC) and flyback designs. The
device can generate 5V at up to 200mA from a 3.3V supply
or 5V at 175mA from four alkaline cells in a SEPIC design.
The LT1613 is available in the 5-lead SOT-23 package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Efficiency Curve
100
95
90
85
80
75
70
65
60
55
50
0
V_IN = 1.5V
V_IN = 4.2V
V_IN = 3.5V
V_IN = 2.8V
50 100 150 200 250 300 350 400
LOAD CURRENT (mA)
1613 TA01a
1