LT1930A_15 Datasheet, PDF (1/12 Pages) Linear Technology – 1A, 1.2MHz/2.2MHz, Step-Up DC/DC Converters in ThinSOT

FEATURES
s _{1.2MHz Switching Frequency (LT1930)}
s _{2.2MHz Switching Frequency (LT1930A)}
s _{Low VCESAT Switch: 400mV at 1A}
s _{High Output Voltage: Up to 34V}
s _{5V at 480mA from 3.3V Input (LT1930)}
s _{12V at 250mA from 5V Input (LT1930A)}
s _{Wide Input Range: 2.6V to 16V}
s _{Uses Small Surface Mount Components}
s _{Low Shutdown Current: < 1µA}
s _{Low Profile (1mm) ThinSOT}^TM _Package
s _{Pin-for-Pin Compatible with the LT1613}
U
APPLICATIO S
s _{TFT-LCD Bias Supply}
s _{Digital Cameras}
s _{Cordless Phones}
s _{Battery Backup}
s _{Medical Diagnostic Equipment}
s _{Local 5V or 12V Supply}
s _{External Modems}
s _{PC Cards}
s _{xDSL Power Supply}
, LTC and LT are registered trademarks of Linear Technology Corporation
ThinSOT is a trademark of Linear Technology Corporation.
LT1930/LT1930A
1A, 1.2MHz/2.2MHz,
Step-Up DC/DC Converters
DESCRIPTIO
in ThinSOT
The LT^®1930 and LT1930A are the industry’s highest
power SOT-23 switching regulators. Both include an
internal 1A, 36V switch allowing high current outputs to be
generated in a small footprint. The LT1930 switches at
1.2MHz, allowing the use of tiny, low cost and low height
capacitors and inductors. The faster LT1930A switches at
2.2MHz, enabling further reductions in inductor size.
Complete regulator solutions approaching one tenth of a
square inch in area are achievable with these devices.
Multiple output power supplies can now use a separate
regulator for each output voltage, replacing cumbersome
quasi-regulated approaches using a single regulator and
custom transformers.
A constant frequency internally compensated current mode
PWM architecture results in low, predictable output noise
that is easy to filter. Low ESR ceramic capacitors can be
used at the output, further reducing noise to the millivolt
level. The high voltage switch on the LT1930/LT1930A 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 LT1930 can
generate 5V at up to 480mA from a 3.3V supply or 5V at
300mA from four alkaline cells in a SEPIC design.
The LT1930/LT1930A are available in the 5-lead ThinSOT
package.
TYPICAL APPLICATIO
L1
V_IN
5V
10µH
D1
5
1
R1
V_OUT
12V
300mA
C1
2.2µF
V_IN
SW
LT1930
4
SHDN SHDN
3
FB
113k
C3*
10pF
C2
4.7µF
GND
R2
2
13.3k
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R EMK316BJ475ML
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CR43-100
*OPTIONAL
1930/A F01
Figure 1. 5V to 12V, 300mA Step-Up DC/DC Converter
Efficiency
90
V_IN = 5V
85
V_IN = 3.3V
80
75
70
65
60
55
50
0
100
200
300
400
LOAD CURRENT (mA)
1930 TA01
1