ACE555
Technology
Description
400mA LDO Dropout Voltage Regulator
ACE555 is a series of low dropout three terminal regulators with a dropout of 1.22V at 400mA load
current.
Other than a fixed version（Vout＝1.8V,2.5V,2.85V,3.3V,5V）, ACE555 has an adjustable version, which
can provide an output voltage from 1.25 to 13.8V with only two external resistors.
ACE555 offers thermal shut down and current limit functions, to assure the stability of chip and power
system. And it uses trimming technique to guarantee output voltage accuracy within
±2％.
ACE555 is available in SOT-89-3 power Package. Lead free package is also available on command.
Features
•
•
•
•
•
•
•
•
•
•
Other than a fixed version and an adjustable version, output value can be customized on command.
Maximum output current is 400mA
Output voltage accuracy is within
±1％
Range of operation input voltage: Max 18V
Line regulation: 0.2％
Load regulation: 0.4％
Environment Temperature: -50℃~140℃
Application
Power Management for Computer Mother Board, Graphic Card
LCD Monitor and LCD TV
DVD Decode Board
Absolute Maximum Ratings
Parameter
Input voltage
Power Dissipation
SOT-89-3
Junction temperature
Environment Temperature
Storage temperature
T
J
T
A
T
S
Symbol
V
IN
Max
18
0.5
150
140
65 to 150
Unit
V
W
O
O
C
C
O
C
VER 1.2
1
ACE555
Technology
Packaging Type
SOT-89-3
400mA LDO Dropout Voltage Regulator
Pin SOT-89-3(A) SOT-89-3(B) SOT-89-3(C)
V
OUT
1
3
2
GND
2
1
1
V
IN
3
2
3
1
2
3
Ordering information
Selection Guide
ACE555 XX XXX + H
Halogen - free
Pb - free
AMA: SOT-89-3
AMB: SOT-89-3
AMC: SOT-89-3
Output Voltage :
1.8V / 2.5V ….. 5.0V
Block Diagram
VER 1.2
2
ACE555
Technology
Recommended Work Conditions
Item
Min Nom Max Unit
Input Voltage Range
18
V
O
Ambient Temperature -50
140
C
400mA LDO Dropout Voltage Regulator
Electrical Characteristics
Symbol
Prameter
Condition
ACE555-1.8V
ACE555-2.5V
ACE555-2.85V
ACE555-3.3V
ACE555-5.0V
Vin=5V½15V
ACE555-5.0V
(Vin=7V~15V)
IL＝0½400mA
ΔVout, ΔVref,=1%，
Iout=400mA
Vin-Vout=2V, Tj=25℃
Min Typical Max Units
1.764
1.80
1.836
V
2.45
2.5
2.55
V
2.793
2.85
2.907
V
3.234
3.3
3.366
V
4.9
5
5.1
V
0.2
0.4
%
0.2
0.2
1.22
600
4
8
0.5
0.4
0.4
1.3
%
%
V
mA
mA
%
Vout
Output Voltage
ΔVout
ΔVout
Dropout
Voltage
Current
Limit
Iq
ΔVout/
ΔT∙Vout
Line Regulation（note1）
Load Regulatiion（note1,2）
Input-Output Voltage
Differentia（note3）
Max Load Current
Quiescent Current
Temperature Stability
Note：1.The Parameters of Line Regulation and Load Regulation in Table1 are tested under constant junction temperature. The
Curve of Load Regulation vs. Temperature is shown in typical parameter curve that follows.
2.When Iout varies between 0~400mA,Vin-Vout varies between 1.5V~12V under constant junction temperature，the
parameter is satisfied the criterion in table. If temperature varies between -50
℃
≤TA≤140
℃，it
needs output current to be
larger than 10mA to satisfy the criterion.
3.Dropout Voltage is specified over the full output current range of the device, and it is tested under following testing
conditions: First step is to find out the Vout value (Vout1) when Vin1=Vout+1.5V, second step is to decrease Vin(Vin2)
until Vout value is equal to 99%*Vout1(Vout2). Vdropout=Vin2-Vout2.
4.Minimum Load Current is defined as the minimum output current required to maintain regulation. When
1.5V
≦
Vin-Vout
≦
12V
，the
device is guaranteed to regulate if the output current is greater than 10mA.
VER 1.2
3
ACE555
Technology
Detailed Description
400mA LDO Dropout Voltage Regulator
ACE555 is a series of low dropout voltage, three terminal regulators. Its application circuit is very simple:
the fixed version only needs two capacitors and the adjustable version only needs two resistors and two
capacitors to work. It is composed of some modules including start-up circuit, bias circuit, bandgap,
thermal shutdown, current limit, power transistors and its driver circuit and so on.
The thermal shut down and current limit modules can assure chip and its application system working
safety when the environment temperature is larger than 140
℃
or output current is larger than 600mA.
The bandgap module provides stable reference voltage, whose temperature coefficient is compensated
by careful design considerations. The temperature coefficient is under 100ppm/
℃
. And the accuracy of
output voltage is guaranteed by trimming technique,
Typical Application
ACE555 has an adjustable version and five fixed versions, Chart1 is its typical application.
ACE555
Vin
+
Cin
10uF
Vin
GND
+
22uF
Cout
Vout
Vout
Application Hints
1.Recommend using 10uF tan capacitor as bypass capacitor(C1) for all application circuit.
2.Recommend using 22uF tan capacitor to assure circuit stability.
3.Using a bypass capacitor(CAdj) between the adjust terminal and ground can improve ripple rejection,
This bypass capacitor prevents ripple from being amplified as the output voltage is increased.The
impedance of CAdj should be less than the resistor’s(R1) which is between output and adjust pins to
prevent ripple from being amplified at any ripple frequency. As R1 is normally in the range of 200Ω~350
Ω,the
value of CAdj should satisfy this equation:2*Fripple*CAdj<R1. Recommend using 10uF tan
capacitor.
VER 1.2
4
ACE555
Technology
Packing Information
SOT-89-3
400mA LDO Dropout Voltage Regulator
VER 1.2
5
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