UM3506QA Datasheet, PDF (1/9 Pages) Union Semiconductor, Inc. – Synchronous Step-Down Converter

UM3506QA
Low-Profile, 600mA, Synchronous Step-Down Converter
with Integrated Inductor
UM3506QA QFN14 2.5×2.5
General Description
The UM3506QA is a complete power conversion solution requiring only two low cost ceramic
MLCC caps. Inductor, MOSFETs, synchronous rectifier and control IC are integrated into a tiny
2.5mm×2.5mm×1.05mm QFN package. The UM3506QA is engineered to simplify design and to
minimize layout constraints. It is an ideal choice to be used to replace less efficient LDO to
achieve improved efficiency in space restricted applications. The UM3506QA is capable of
delivering 600mA output current over a wide input voltage range from 2.5V to 5.5V.
The UM3506QA is a high-efficiency, step-down DC-DC converter with a constant PWM
frequency, current mode architecture. The UM3506QA automatically turns off the synchronous
rectifier while the inductor current is low, and enters pulse skipping mode at light load condition.
This can increase efficiency. The operation frequency is set to 2.25MHz at normal load condition.
The UM3506QA enters shutdown mode and consumes less than 0.1µA when EN pin is pulled
low.
Applications
Features
 Cellular and Smart Phones
 MCU, DSP and FPGA Core Supplies
 Wireless and DSL Modems
 Portable Game Consoles and
Instruments
 PDAs, GPS
 Bluetooth Headsets
 Battery-Powered Devices
 Tiny QFN Package 2.5×2.5×1.05
 Integrated Inductor
 No Schottky Diode Required
 High Efficiency: Up to 90%
 600mA Output Current
 0.6V Minimum Output Voltage
 2.5V to 5.5V Input Voltage Range
 <1µA Shutdown Current
 Pulse Skipping Mode Operation
 Thermal Fault Protection
Typical Application Circuit
VIN 2.5V to 5.5V
CIN
SW ^{L2 L1}
VIN
PVOUT
EN
UM3506QA
MODE
FB
GND
VOUT
1.8V
R1
C1
360kΩ 22pF
COUT
R2
180kΩ
Light Load Efficiency
Light Load Efficiency vs. Input Voltage
100
90
80
70
60
50
40
30
20
IL^IOLOAADD⁼=0⁰.^.5⁵m^mA^A
IL^IO^LOA^AD^D==0⁰.^.8⁸m^mA^A
10
IL^IO^LOA^AD^D==1¹.^.0⁰m^mA^A
VOUT=1.8V
0
2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
Input Voltage (V)
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http://www.union-ic.com Rev.01 Oct.2016
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