1

LT1949

600kHz, 1A Switch

PWM DC/DC Converter

3.3V

SW

FB

LT1949

L1

10

µH

D1

R2

140k

68k

330pF

10V

175mA

R1

1M

1949 F01

C2

10

µF

CERAMIC

C1

22

µF

GND

SHDN

SHUTDOWN

C1: AVX TAJA226M006R

C2: TAIYO YUDEN LMK325BJ106MN

D1: MBRM120LT3

L1: SUMIDA CDRH62B-100

+

The LT

verter with a 1A, 0.5

Ω internal switch. Capable of gener-

ating 10V at 175mA from a 3.3V input, the LT1949 is ideal

for generating bias voltages for large screen LCD panels.

Constant frequency 600kHz operation results in a low

noise output that is easy to filter and the 30V switch rating

allows output voltage up to 28V using a single inductor. An

external compensation pin gives the user flexibility in

optimizing loop compensation, allowing small low ESR

ceramic capacitors to be used at the output. The 8-lead

MSOP and SO packages ensure a low profile overall

solution.

The LT1949 includes a low-battery detector that stays

alive when the device goes into shutdown. Quiescent

current in shutdown is 25

µA, while operating current is

4.5mA.

s

1A, 0.5

Ω, 30V Internal Switch

s

s

600kHz Fixed Frequency Operation

s

Low-Battery Detector Stays Active in Shutdown

s

s

Pin-for-Pin Compatible with the LT1317B

s

Small 8-Lead MSOP and SO Packages

s

LCD Bias Supplies

s

GPS Receivers

s

Battery Backup

s

Portable Electronic Equipment

s

Diagnostic Medical Instrumentation

, LTC and LT are registered trademarks of Linear Technology Corporation.

Figure 1. 3.3V to 10V/175mA DC/DC Converter

Figure 2. 3.3V to 10V Converter Efficiency

LOAD CURRENT (mA)

90

80

70

60

50

40

30

20

5

100

50

300

1949 F02

10

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO