RT8023
1
DS8023-03 March 2011 www.richtek.com
Ordering Information
Applications
z Portable Instruments
z Microprocessors and DSP Core Supplies
z Cellular Phones
z Wireless and DSL Modems
z PC Cards
z Digital Cameras
1.2MHz 1.5A Synchronous Step-Down Converter
with Two LDOs
General Description
The RT8023 combines two low dropout (LDO) linear
regulators and a step-down converter with an input voltage
range of 2.6V to 5.5V. Each output voltage is adjustable
from 0.8V to 5V. With independent Enable and Power-
Good pins for each regulator, it is easy to control the power
up sequence, which is important in some applications.
The
LDO has an independent input and is capable of
delivering up to 700mA(LDO1) and 350mA(LDO2) output
currents with ultra-low dropout. The LDO has high PSRR
and can work with low-ESR space saving ceramic
capacitors. All these make it Ideal for portable RF and
wireless applications with demanding performance and
space requirements. Other features include high output
accuracy, current limiting protection, and 40μs fast turn-
on time.
The step-down converter is a 1.2MHz PWM, current mode
converter. Its high switching frequency allows the use of
tiny, low cost capacitors and inductors 2mm or less in
height. Internal power switches with low on-resistance
increase efficiency and eliminate the need for external
Schottky diodes. The converter can run at 100% duty cycle
for low dropout operation that extends battery life in
portable systems.
Features
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Converter Input Voltage Range : 2.6V to 5.5V,
LDO Input Voltage Range : 2.4V to 5.5V
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z Low-Noise LDO for RF Application
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z Ultra-Fast Response in Line/Load Transient
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z LDO Turn-On Time Less Than 40us
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z Only 1
μμ
μμ
μF LDO Output Capacitor Required for
Stability
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z Current Limiting Protection
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z 1.5A, High Efficiency Step-Down Converter
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z 1.2MHZ Constant Switching Frequency
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z Low R
DS(ON)
Internal Switches
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z No Schottky Diode Required
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z 0.8V Reference Allows Low Output Voltage
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z Low Dropout Operation : 100% Duty Cycle
Internally Compensated
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z < 2
μμ
μμ
μA Shutdown Current
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z Power Good Output Voltage Monitor
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z Internal Soft-Start for PWM Converter
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z Easy Power Sequence Control
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z Over Temperature Protection
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z Short Circuit Protection
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z Thermally Enhanced 24-Lead WQFN Package
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z RoHS Compliant and 100% Lead (Pb)-Free
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Package Type
QW : WQFN-24L 4x4 (W-Type)
RT8023
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
