Rev. 10/11/00
AS2880
8A Low Dropout Voltage Regulator
Adjustable & Fixed 3.3V
FEATURES
APPLICATIONS
• Adjustable Output Down to 1.2V or Fixed 3.3V & 5V • Powering Intel Pentium µP from +5V Supplies
• Output Current of 8A • Power PCSupplies
• Low Dropout Voltage • SMPS Post-Regulator
• Extremely Tight Load and Line Regulation • High Efficiency “Green” Computer Systems
• Current & Thermal Limiting • High Efficiency Linear Power Supplies
• Standard 3-Terminal Low Cost TO-220 • Portable Instrumentation
• Similar to Industry Standard LT1083/LT1584 • Constant Current Regulators
• Adjustable Power Supplies
• Battery Charger
PRODUCT DESCRIPTION
The AS2880 is a low power 8A Adjustable Voltage Regulator that is very easy to use. It requires only 2 external resistors to set the
output voltage. This device is an excellent choice when using Powering Intel Microprocessor to convert from +5V to 3.3V supplies,
and as a post regulator for switching supplies applications. The AS2880 features low dropout of a maximum 1.5 volts.
The AS2880 offers full protection against over-current faults, reversed input polarity, reversed load insertion, over temperature
operation, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The IQ of this device
flows into the load, which increases efficiency.
The AS2880 is offered in a 3-pin TO-220 package compatible with older 3-terminal regulators. When using ALPHA Semiconductor
design, processing and testing techniques make AS2880 superior over similar products on the market. For a 5A low dropout regulator
refer to the AS2850 datasheet.
ORDERING INFORMATION
TO-220
3-PIN
AS2880AU
X = Output Voltage (i.e. 3.3 for 3.3V, 5.0 for 5.0V etc.)
Y = Output Tolerance, A for 1%
Blank for 2%
Consult factory for other fixed voltages.
Front View
TO-220-3 (U)
AS2880
123
ADJ/GND V
OUT
V
IN
PIN CONNECTIONS
Rev. 10/11/00
AS2880
ABSOLUTE MAXIMUM RATINGS
Power Dissipation..........................................Internally Limited Input Supply Voltage .................................................... +10V
Lead Temp. (Soldering, 10 Seconds) .............................. 300°C Input to Output Voltage Differential .............................. 8.8V
Storage Temperature Range ............................ -65° to +150°C
Operating Junction Temperature Range
AS2880 Control Section ............................0C° to +125°C
AS2880 Power Transistor..........................0C° to +150°C
ELECTRICAL CHARACTERISTICS (Note 1) at IOUT = 10mA, TA = 25°C, unless otherwise specified.
Parameter Conditions AS2880A AS2880 Units
Typ Min Max Min Max
3.3V Version
Output Voltage (Note 2) AS2880-3.3V, 0≤IOUT1.5A,
4.75V≤VIN≤7V
3.3
3.3
3.270
3.240
3.330
3.360
3.230
3.201
3.370
3.399
V
5.0V Version
Output Voltage (Note 2) AS2880-3.3V, 0≤IOUT1.5A,
6.5V≤VIN≤7V
5.0
5.0
4.950
4.900
5.050
5.100
4.900
4.650
5.100
5.150
All Voltage Options
Reference Voltage 10mA ≤ IOUT ≤ IFULLLOAD
3.3V≤(VIN - VOUT )≤ VIN MAX – VOUT MAX
1.250
1.250
1.238
1.225
1.262
1.270
1.238
1.225
1.262
1.270
V
Mid Load Current (VIN- VOUT) = VIN MAX – VOUT MAX 5 10 10 mA
Line Regulation 1.5V ≤VIN - VOUT ≤ VIN MAX – VOUT MAX
ILOAD = 10mA
0.015
0.05
0.2
0.5
0.2
0.5
%
Load Regulation 10mA ≤ IOUT ≤ IFULLLOAD
(VIN - VOUT)=3V
0.1
0.2
0.3
0.4
0.3
0.4
%
Dropout Voltage IOUT=IFULLLOAD , ∆VREF=1% 1.1 1.2 1.2 V
Current Limit VIN - VOUT=5V 9.5 8.0 8.0 A
Long Term Stability TA=125°C, 1000Hrs. 0.3 1 1 %
Adjust Pin Current TA=25°C 55 90 90 µA
Adjust Pin Current
Change
0.2 5 5 µA
Thermal Regulation 30ms pulse 0.003 0.01 0.01 %/W
Temperature Stability 0.5 %
Ripple Rejection Ratio VIN - VOUT=3V
IOUT =3A, COUT = 25µF, CADJ = 25µF,
f= 120Hz
75 60 60 dB
Output Noise, RMS 10Hz to 10kHz 0.003 % VO
Thermal Resistance
Junction-to-Case
TO-220 Junction to Tab
Junction to Ambient
2.7
0.65
2.7
0.65
°C/W
The Bold specifications apply to the full operating temperature range.
Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 2: A 10µF output capacitor is required on AS2880
Rev. 10/11/00
AS2880
TYPICAL CHARACTERISTICS
Rev. 10/11/00
AS2880
TYPICAL APPLICATIONS
LOAD
ADJ
AS2880
8A Current Output Regulator
V
IN
C
1
R
1
OUT
IN
Pentium Processor is a trademark of Intel Corp. Power PC is a trademark of IBM Corp.
IN OUT
ADJ
AS2880
C1
R1
R2
Powering Intel Pentium
TM with AS2880
VIN
Intel PentiumTM
+5V
C2
3.45V
VCC
IN
OUT
ADJ
AS2880
C
1
R
1
R
2
V
OUT
Typical Adjustable Regulator
V
OUT
= V
REF 2
+ I
ADJ
V
IN
C
2
R
1
V
REF
R1+ R
2
