ACE ACE722A

ACE722A
Technology
2A PWM BUCK DC-DC Converter
Description
ACE722A is a 420kHz fixed frequency PWM buck (step-down) DC-DC converter, capable of driving a 2A
load with high efficiency, low ripple and excellent line and load regulation. The device includes a voltage
reference, an oscillation circuit, an error amplifier, an internal PMOS and etc.
The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. The enable function, over
current protection function, short circuit protection function and soft-start function are built inside. When
OCP or SCP happens, the operation frequency will be reduced from 420kHz to 40kHz. An internal
compensation block is employed to minimize external components.
The ACE722A serves as an ideal power supply unit for portable devices, especially for chip set power in
portable systems. It’s widely used for PDVD, LCD monitor and DPF chip set powers.
Features
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2A Constant Output Current
130mΩ RDSON Internal Power MOSFET Switch
Up to 94% Efficiency
Fixed 420kHz Frequency
Wide 4.75V to 25V Input Voltage Range
Output Voltage Adjustable from 0.8V to 21V
Built in Thermal Shutdown Function
Built-in Current Limit Function
Built-in Soft-Start Function
Support Ceramic or Electrolytic Capacitors
Application
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Portable DVE
LCD Monitor/LCD TV
Digital Photo Frame
ADSL
Set-up Box
Absolute Maximum Ratings
Parameter
Symbol
Max
Unit
Input Voltage
FB Pin Voltage
VIN
VFB
-0.3 to 30
-0.3 to 6
V
V
EN Pin Voltage
VEN
-0.3 to VIN
V
COMP Pin Voltage
VCOMP
-0.3 to 6
V
SW Pin Voltage
VSW
-0.3 to VIN
V
Power Dissipation
PD
Internally Limited mW
O
Thermal Resistance (Junction to Ambient, No Heat Sink, Free AIR) θJA
100
C/W
O
Operating Junction Temperature
TJ
150
C
O
Storage Temperature
TSTG
-65 to 150
C
O
Lead Temperature (Soldering, 10sec)
TLEAD
260
C
ESD (Human Body Model)
ESD
2000
V
VER 1.2
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ACE722A
Technology
2A PWM BUCK DC-DC Converter
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.
Packaging Type
SOP-8
1
8
2
7
3
6
4
5
Pin SOP-8
1
NC
2
VIN
3
4
SW
GND
Function
Not Connected
Supply Voltage Input Pin. ACE722A operates from a 4.75V to 25V DC voltage. Bypass
VIN to GND with a suitable large capacitor to eliminate noise on the input.
Power Switch Output Pin. SW is the switch node that supplies power to the output.
Ground Pin
Feedback Pin. Through an external resistor divider network, FB senses the output voltage
5
FB
and regulates it. To prevent current limit run away in a short circuit fault condition, the
frequency feedback comparator lowers the oscillator frequency to 40kHz when the FB
voltage is below 0.52V. The feedback threshold voltage is 0.8V.
6
COMP
7
EN
8
NC
Compensation Pin. This pin is the output of the error amplifier. Frequency compensation
is done at this pin by connecting a series RC to ground (parallel a C if necessary)
Enable Pin. Drive EN pin high to turn on the device, drive it low to turn off. Default of this
pin is high level.
Not Connected
VER 1.2
2
ACE722A
Technology
2A PWM BUCK DC-DC Converter
Ordering information
Selection Guide
ACE722A XX +
H
Halogen - free
Pb - free
FM : SOP-8
Block Diagram
Recommended Operating Conditions
Parameter
Symbol
Min
Max
Unit
Input Voltage
VIN
4.75
25
V
Output Voltage
VOUT
0.8
21
V
Operating Junction Temperature
TJ
-40
125
℃
VER 1.2
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ACE722A
Technology
2A PWM BUCK DC-DC Converter
Electrical Characteristics
(Vcc=12V, VOUT=5V, TA=25℃, unless otherwise noted.)
Parameter
Input Voltage
Shutdown Quiescent Current
Quiescent Current
Feedback Voltage
Feedback Bias Current
Switch Current Limit
Oscillator Frequency
Frequency of Current Limit or Short
Circuit Protection
Error Amplifier Voltage Gain
Error Amplifier Transconductance
Symbol
VIN
ISHDN
IQ
VFB
IFB
ILIM
fosc
VEN=0.4V
VEN=2V, VFB=1.3V
VIN=5V to 25V
VFB=1.3V
fosc1
VFB<0.52V
EN Pin Input Leakage Current
GV
GS
VH
VL
IEN
Internal PMOS ON Resistance
RDSON
Maximum Duty Cycle
DMAX
Thermal Shutdown
Thermal Shutdown Hysteresis
TOTSD
THYS
EN Pin Threshold
Conditions
Min
4.75
0.784
2.5
336
Typ
44
1.3
0.8
-0.1
3.4
420
Max Units
25
V
60
μA
2
mA
0.816
V
-0.5
μA
A
504
kHz
40
kHz
1000
700
-5
0.7
-10
V/V
μA/V
V
V
μA
130
150
mΩ
100
%
1.5
VEN=2.5V
VIN=12V
VFB=0.65V
VEN=12V,IOUT=2A
VFB=0.65V,
ISW=0.1A
155
20
℃
℃
Typical Performance Characteristics
VCC=12V, VOUT=5V, TA=25℃, unless otherwise specified
Output Current (A)
Figure 1. Efficiency vs. Output Current
Temperature (℃)
Figure 2. Operation Frequency vs. Temperature
VER 1.2
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ACE722A
Technology
Input Voltage (V)
Figure 3. Supply Quiescent Current vs. Input Voltage
Input Voltage (V)
Figure 5. Shutdown Quiescent Current vs. Input Voltage
Temperature (℃)
Figure 7. Feedback Voltage vs. Temperature
2A PWM BUCK DC-DC Converter
Input Voltage (V)
Figure 4. Efficiency vs. Input Voltage
Temperature (℃)
Figure 6. OCP Current Limit vs. Temperature
Input Voltage (V)
Figure 8. OCP Current Limit vs. Input Voltage
VER 1.2
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ACE722A
Technology
Temperature (℃)
2A PWM BUCK DC-DC Converter
Output Current (A)
Figure 9. OCP Frequency vs. Temperature
Figure 10. Output Voltage vs. Output Current
Typical Application
(VIN=12V, VOUT=5V, IOUT=2A)
ACE722A
Figure 11. Typical Application 1 of ACE722A Applied with Ceramic Input and Output Capacitors
VER 1.2
6
ACE722A
Technology
2A PWM BUCK DC-DC Converter
ACE722A
Figure 12. Typical Application 2 of ACE722A Applied with Electrolytic Input and Output Capacitors
VER 1.2
7
ACE722A
Technology
2A PWM BUCK DC-DC Converter
Packing Information
SOP-8
VER 1.2
8
ACE722A
Technology
2A PWM BUCK DC-DC Converter
Notes
ACE does not assume any responsibility for use as critical components in life support devices or systems
without the express written approval of the president and general counsel of ACE Electronics Co., LTD.
As sued herein:
1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and shoes failure to perform when properly used in
accordance with instructions for use provided in the labeling, can be reasonably expected to result in
a significant injury to the user.
2. A critical component is any component of a life support device or system whose failure to perform can
be reasonably expected to cause the failure of the life support device or system, or to affect its safety
or effectiveness.
ACE Technology Co., LTD.
http://www.ace-ele.com/
VER 1.2
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