UM3433 Datasheet, PDF (1/9 Pages) Union Semiconductor, Inc. – 600mA, 600kHz Step-Up DC-DC Converter

UM3433
600mA, 600kHz Step-Up DC-DC Converter
UM3433 SOT23-6
General Description
The UM3433 is synchronous rectified, fixed frequency, step-up DC/DC converter series
delivering high efficiency in a low profile SOT23-6 package. It is available both in 3.3V/3.0V
fixed output and adjustable output. With an internal NMOS switch and PMOS synchronous
rectifier and high switching frequency of 600KHz, the UM3433 is capable of supplying 3.3V
output at 100mA from a single AA cell input using low profile inductors and ceramic capacitors.
Current mode PWM control with internal compensation cuts external parts count thereby saving
BOM cost and PCB real estate. At light loads, UM3433 enters automatically into power saving
mode to keep high efficiency at light load. Anti-ringing control circuitry inside reduces EMI
interferences by damping the inductor in discontinuous mode.
The device also features low shutdown current of under 1 μA. With inrush current limiting and
soft start built inside, it also limits the inrush of current during start up, minimizing surge currents
seen by the input supply.
Applications
Features
z MP3 Players
z Digital Cameras
z LCD Bias Supplies
z Handheld Instruments
z Wireless Handsets
z GPS Receivers
z Up to 92% efficiency
z Low Voltage Start-Up: 0.9V
z Inrush current limiting and internal soft
start
z Automatic Power-Saving Mode Operation
with typical IQ as 20μA
z Short Circuit Protection
z 600kHz Switching Frequency for low
profile inductor/capacitor
z Anti-ringing Control to minimizes EMI
z Output range: 2.5V to 5V, with 3.3V/3.0V
fixed output option
Pin Configurations
Top View
(*: only available for adjustable version)
UM3433-3.3 (UCR)
UM3433-3.0 (UDR)
UM3433-ADJ (UCS)
SOT23-6
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http://www.union-ic.com Rev.05 Dec.2009
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