Document
Data Sheet
1.5MHz, 1A, STEP DOWN DC-DC CONVERTER
AUR9705
General Description
The AUR9705 is a high efficiency step-down DC-DC voltage converter. The chip operation is optimized using constant frequency, peak-current mode architecture with built-in synchronous power MOSFET switchers and internal compensators to reduce external part counts. It is automatically switching between the normal PWM mode and LDO mode to offer improved system power efficiency covering a wide range of loading conditions.
The oscillator and timing capacitors are all built-in providing an internal switching frequency of 1.5MHz that allows the use of small surface mount inductors and capacitors for portable product implementations. Additional features included Soft Start (SS), Under Voltage Lock Out (UVLO) and Thermal Shutdown Detection (TSD) to provide reliable product applications.
The device is available in adjustable output voltage versions ranging from 1V to 3.3V, and is able to deliver up to 1A.
The AUR9705 is available in WDFN-2×2-6 and TSOT-23-5 packages.
Features
• High Efficiency Buck Power Converter • Low Quiescent Current • Output Current: 1A • Adjustable Output Voltage from 1V to 3.3V • Wide Operating Voltage Range: 2.5V to 5.5V • Built-in Power Switches for Synchronous
Rectification with High Efficiency • Feedback Voltage: 600mV • 1.5MHz Constant Frequency Operation • Automatic PWM/LDO Mode Switching Control • Thermal Shutdown Protection • Low Drop-out Operation at 100% Duty Cycle • No Schottky Diode Required
Applications
• Mobile Phone, Digital Camera and MP3 Player • Headset, Radio and Other Hand-held Instrument • Post DC-DC Voltage Regulation • PDA and Notebook Computer
WDFN-2×2-6
TSOT-23-5
Nov. 2011 Rev. 1. 0
Figure 1. Package Types of AUR9705
BCD Semiconductor Manufacturing Limited 1
Data Sheet
1.5MHz, 1A, STEP DOWN DC-DC CONVERTER
AUR9705
Pin Configuration
D Package (WDFN-2×2-6)
H Package (TSOT-23-5)
Pin 1 Mark
NC 1 EN 2 VIN 3
Exposed Pad
6 FB 5 GND 4 LX
15 2 34
Figure 2. Pin Configuration of AUR9705 (Top View)
Pin Description
Pin Number WDFN-2×2-6 TSOT-23-5
1 23 31 45 52
64
Pin Name
NC EN VIN LX GND
FB
Function
No internal connection (Floating or connected to GND) Enable signal input, active high Power supply input Connect to inductor This pin is the GND reference for the NMOS power stage. It must be connected to the system ground Feedback voltage from the output of the power supply
Nov. 2011 Rev. 1. 0
BCD Semiconductor Manufacturing Limited 2
1.5MHz, 1A, STEP DOWN DC-DC CONVERTER
Functional Block Diagram
Data Sheet
AUR9705
Figure 3. Functional Block Diagram of AUR9705
Ordering Information
AUR9705
Circuit Type A: Adjustable Output
Package D: WDFN-2×2-6 H: TSOT-23-5 G: Green
Package
WDFN-2×2-6 TSOT-23-5
Temperature Range
-40 to 80°C
Part Number
AUR9705AGD AUR9705AGH
Marking ID
705A 9705AG
Packing Type
Tape & Reel Tape & Reel
BCD Semiconductor's Pb-free products, as designated with "G" in the part number, are RoHS compliant and green.
Nov. 2011 Rev. 1. 0
BCD Semiconductor Manufacturing Limited 3
1.5MHz, 1A, STEP DOWN DC-DC CONVERTER
Absolute Maximum Ratings (Note 1)
Data Sheet
AUR9705
Parameter
Supply Input Voltage Enable Input Voltage Switch Output Voltage Power Dissipation (On PCB, TA=25°C) Thermal Resistance (Junction to Ambient, Simulation) Thermal Resistance (Junction to Case, Simulation) Operating Junction Temperature Operating Temperature Storage Temperature ESD (Human Body Model) ESD (Machine Model)
Symbol
VIN VEN VLX PD θJA θJC TJ TOP TSTG VHBM VMM
Value
0 to 6.0 -0.3 to VIN+0.3 -0.3 to VIN+0.3
1.89 53 0.85 160
-40 to 85 -55 to 150
2000 200
Unit
V V V W °C/W °C/W °C °C °C V V
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.
Recommended Operating Conditions
Parameter
Supply Input Voltage Junction Temperature Range Ambient Temperature Range
Symbol
VIN TJ TA
Min
2.5 -20 -40
Max
5.5 125 80
Unit
V °C °C
Nov. 2011 Rev. 1. 0
BCD Semiconductor Manufacturing Limited 4
Data Sheet
1.5MHz, 1A, STEP DOWN DC-DC CONVERTER
AUR9705
Electrical Characteristics
VIN=VEN=5V, VFB=0.6V, L=2.2µH, CIN= 4.7µF, COUT=10µF, TA=25°C, unless otherwise specified.
Parameter
Input Voltage Range
Shutdown Current
Regulated1Feedback Voltage
Regulated Output Voltage Accuracy
Peak Current
Inductor
Oscillator Frequency
PMOSFET RON NMOSFET RON
Quiescent Current
Symbol
VIN IOFF VFB
∆VOUT/VOUT
IPK fOSC RON(P) RON(N) IQ
Conditions
VEN=0V For Adjustable Output Voltage VIN=2.5V to 5.5V, IOUT=0 to 1A VFB=0.5V
IOUT =200mA IOUT =200mA IOUT=0A, VFB=0.7V
LX Leakage Current ILX VEN=0V, VLX=0V or 5V
Feedback Current
EN Leakage Current EN High-level Input V.