Diodes AUR9718B User Manual
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Data Sheet
General Description
The AUR9718B is a high efficiency step-down
DC-DC voltage converter. The chip operation is
optimized by peak-current mode architecture with
built-in synchronous power MOSFET switchers.
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 including Soft Start (SS), Under
Voltage Lock Out (UVLO), Thermal Shutdown
Detection (TSD) and short circuit protection are
integrated to provide reliable product applications.
The device is available in adjustable output voltage
versions ranging from 0.8V to V
voltage range is from 2.7V to 5.5V, and is able to
deliver up to 2.5A.
The AUR9718B is available in DFN-3×3-6 package.
when input
IN
Features
• High Efficiency Buck Power Converter
• Low R
• Output Current: 2.5A
• Adjustable Output Voltage from
• Wide Operating Voltage Range: 2.7V to 5.5V
•
4Built-in Power Switchers for Synchronous
Rectification with High Efficiency
• Feedback Voltage Allows Output: 800mV
• 1.5MHz Switching Frequency
• Thermal Shutdown Protection
• Low Drop-out Operation at 100% Duty Cycle
• No Schottky Diode Required
• Input Over Voltage Protection
Internal Switches : 100mΩ
DS(ON)
0.8V to VIN
Applications
• LCD TV
• Set Top Box
• Post DC-DC Voltage Regulation
• PDA and Notebook Computer
DFN-3×3-6
Figure 1. Package Type of AUR9718B
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Pin Configuration
D Package
(DFN-3×3-6)
Pin 1 Mark
1
2
Figure 2. Pin Configuration of AUR9718B (Top View)
Exposed
Pad
6
5
43
Pin Description
Pin Number Pin Name Function
1 FB Output voltage feedback pin
2 GND Ground pin
3 SW Switch output pin
4 VIN_SW Power supply input for the MOSFET switch
5 VIN_A Supply input for the analog circuit
6 EN Enable pin, active high
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Functional Block Diagram
-
+
VIN_SW
4
3
2
GND
SW
FB
1
EN
6
Bias
Generator
Soft
Start
Bandgap
Reference
VIN_A
Saw-tooth
Generator
Oscillator
Over Current
Comparator
+
Buffer &
Dead Time
-
+
Error
Amplifier
+
-
Modulator
-
+
Over Voltage
Comparator
Figure 3. Functional Block Diagram of AUR9718B
Control
Logic
Reverse Inductor
Current Comparator
5
Current
Sensing
Control
Logic
Ordering Information
AUR9718B
Circuit Type
Package
DFN-3×3-6 -40 to 80°C AUR9718BGD 9718B Tape & Reel
Temperature
Range
Part Number Marking ID Packing Type
BCD Semiconductor's Pb-free products, as designated with "G" in the part number, are RoHS compliant and
green.
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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Package
D: DFN-3×3-6
G: Green
Data Sheet
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Absolute Maximum Ratings (Note 1)
Parameter Symbol Value Unit
Supply Input Voltage ( pin VIN_SW) V
Supply Input Voltage ( pin VIN_A) V
SW Pin Switch Voltage VSW -0.3 to V
Enable Voltage VEN -0.3 to V
SW Pin Switch Current ISW 3.5 A
Power Dissipation (On PCB, TA=25°C) PD
Thermal Resistance (Junction to Ambient, Simulation) θJA
Operating Junction Temperature TJ
Operating Temperature TOP
Storage Temperature T
ESD (Human Body Model) V
ESD (Machine Model) VMM
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.
IN_SW
IN_A
STG
HBM
0 to 6.5
0 to 6.5
IN_SW
IN_A
2.49
40.11
150
-40 to 85
-55 to 150
2000
200
+0.3 V
+0.3 V
V
V
W
°C/W
°C
°C
°C
V
V
Recommended Operating Conditions
Parameter Symbol Min Max Unit
Supply Input Voltage VIN 2.7 5.5 V
Junction Temperature Range TJ -40 125 °C
Ambient Temperature Range TA -40 80 °C
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Electrical Characteristics
V
IN_SW=VIN_A=VEN
otherwise specified.
Parameter Symbol Conditions Min Typ Max Unit
Input Voltage Range VIN 2.7 5.5 V
=5V, V
=1.2V, VFB=0.8V, L=3.3µH, CIN=4.7µF, C
OUT
=22µF, TA=25°C, unless
OUT
Shutdown Current I
Active Current ION V
Regulated Feedback
Voltage
Regulated Output
Voltage Accuracy
∆V
Peak Inductor
Current
Oscillator Frequency f
PMOSFET RON R
NMOSFET RON R
EN High-level Input
Voltage
EN Low-level Input
Voltage
V
OFF
For Adjustable Output Voltage 0.784 0.8 0.816 V
V
FB
OUT/VOUT
I
OSC
ON(P)
ON(N)
V
EN_H
V
EN_L
3.0 3.5 A
PK
1.2 1.5 1.8 MHz
ISW=0.75A 100 mΩ
ISW=0.75A 100 mΩ
1.5 V
0.4 V
=0V 1 µA
EN
=0.95V 310 µA
FB
=2.7V to 5.5V, I
V
IN
to 2.5A
OUT
=10mA
-3 3 %
EN Input Current IEN 1 µA
Soft-start time tSS 400 µS
Maximum Duty
Cycle
Under Voltage Lock
Out
100 %
D
MAX
Rising 2.4
V
UVLO
Falling 2.3
V
Hysteresis Hysteresis 0.1 V
OVP Threshold V
5.8 5.9 6.0 V
OVP
Hysteresis on OVP 300 400 500 mV
Thermal Shutdown TSD Hysteresis=30°C 150 °C
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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Data Sheet
1.5MHz, 2.5A, Step-down DC-DC Converter AUR9718B
Typical Performance Characteristics
100
90
80
70
60
50
Efficiency (%)
40
30
20
10
0
VIN=5V, V
0.00.51.01.52.02.5
OUT
=3.3V
Output Current (A)
Figure 4. Efficiency vs. Output Current Figure 5. Efficiency vs. Output Current
100
90
80
70
60
50
40
Efficiency (%)
30
20
10
VIN=5V, V
0
0.0 0.5 1.0 1.5 2.0 2.5
OUT
=1.2V
Output Current (A)
100
90
80
70
60
50
40
Efficiency (%)
30
20
10
0
VIN=5V, V
0.0 0.5 1.0 1.5 2.0 2.5
OUT
=1.0V
Output Current (A)
Figure 6. Efficiency vs. Output Current Figure 7. 3.3V Load Regulation
3.40
3.38
3.36
3.34
3.32
3.30
3.28
Output Voltage (V)
3.26
3.24
3.22
3.20
VIN=5V, V
0.0 0.5 1.0 1.5 2.0 2.5
OUT
=3.3V
Output Current (A)
Nov. 2012 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
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