Sipex AS2815 1.5a low dropout voltage regulator adjustable & fixed output, fast response Datasheet

AS2815
1.5A Low Dropout Voltage Regulator
Adjustable & Fixed Output,
Fast Response
FEATURES
APPLICATIONS
• Adjustable Output Down To 1.2V
• Fixed Output Voltages 1.5V, 2.5V, 3.3V, 5.0V
• Output Current of 1.5A
• Low Dropout Voltage 1.1V Typ.
• Extremely Tight Load And Line Regulation
• Current & Thermal Limiting
• Standard 3-Terminal Low Cost TO-220, TO-263 & TO-252
• Similar To Industry Standard LT1086/LT1586
• Powering VGA & Sound Card
• Power PCSupplies
• SMPS Post-Regulator
• High Efficiency “Green” Computer Systems
• High Efficiency Linear Power Supplies
• Portable Instrumentation
• Constant Current Regulators
• Adjustable Power Supplies
• Battery charger
PRODUCT DESCRIPTION
The AS2815 is a low power 1.5A adjustable and fixed voltage regulators that are very easy to use. It requires only 2 external resistors
to set the output voltage for adjustable version. The AS2815 are designed for low voltage applications that offers lower dropout
voltage and faster transient response. This device is an excellent choice for use in powering low voltage microprocessor that require a
lower dropout, faster transient response to regulate from +2.5V to 3.8V supplies and as a post regulator for switching supplies
applications. The AS2815 features low dropout of a maximum 1.2V.
The AS2815 offers over current limit and protection against over-current faults, reversed input polarity, reversed load insertion, and
positive and negative transient voltage. The IQ of this device flows into the load, which increases efficiency.
The AS2815 are offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For a 3A low
dropout regulator refer to the AS2830 data sheet.
ORDERING INFORMATION
TO-220
3-PIN
AS2815YU-X
DD PLASTIC
3-PIN
AS2815YT-X
TO-252
DPAK
AS2815YR-X
OPERERATING JUNCTION
TEMP RANGE
-45 to +125°C
X = Output Voltage (i.e. 1.5 for 1.5V, 2.5 for 2.5V etc.).
Y = Output Tolerance, Y= A for 1% or
Blank for 2%
Consult with factory for other fixed output voltages
PIN CONNECTIONS
TO-263-3 (T)
TO-220-3 (U)
TO-252 (R)
AS2815
1
2
3
AS2815
1
2
3
AS2815
1
2
3
ADJ/GND VOUT VIN
ADJ/GND VOUT VIN
Top View
Front View
ADJ/GND VOUT VIN
Front View
Rev. 10/11/00
AS2815
ABSOLUTE MAXIMUM RATINGS
Lead Temp. (Soldering, 10 Seconds) .............................. 300°C
Storage Temperature Range ............................ -65° to +150°C
Operating Junction Temperature Range ......................
AS2815 Control Section ............................ -45°C +125°C
AS2815 Power Transistor...........................-45°C +150°C
Maximum Input Supply Voltage .......................... 10V
Input to Output Voltage Differential .................... 10V
ELECTRICAL CHARACTERISTICS (NOTE 1) at IOUT = 10mA, Ta=25°C, unless otherwise specified.
AS2815A
PARAMETER
CONDITIONS
Typ
Min
Max
AS2815
Min
Max
Units
1.5V Version
Output Voltage (Note 2)
AS2815-1.5V, 0 ≤IOUT≤1.5A, 2.75V≤VIN ≤7V
1.5
1.5
1.485
1.470
1.515
1.530
1.470
1.455
1.530
1.545
V
2.5V Version
Output Voltage (Note 2)
AS2815-2.5V,0 ≤IOUT≤1.5A, 3.5V≤VIN ≤7V
2.5
2.5
2.475
2.450
2.525
2.550
2.450
2.425
2.550
2.575
V
3.3V Version
Output Voltage (Note 2)
AS2815-3.3V, 0 ≤IOUT≤1.5A, 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)
AS2815-5.0V, 0 ≤IOUT≤1.5A, 5.5V≤VIN ≤7V
5.0
5.0
4.95
4.90
5.05
5.10
4.900
4.850
5.100
5.150
V
VIN≤ 7V, P≤ PMAX
1.5V≤ (VIN -VOUT)≤5.75V, 10mA≤IOUT≤1.5A
1.5V≤ (VIN -VOUT)≤5.75V
1.250
5
1.225
1.270
10
1.225
1.270
10
mA
2.75V≤VIN ≤7V, IOUT=10mA, TJ=25°C (Note 3)
0.005
0.2
0.2
%
VIN ≤7V, IOUT=0mA, TJ=25°C (Note 2)
0.005
0.2
0.2
%
10mA≤IOUT ≤1.5A, (VIN-VOUT)=3V, TJ=25°C
(Note 3)
0.05
0.3
0.3
%
0≤IOUT ≤1.5A, VIN=7V, TJ=25°C (Note 2)
0.05
0.3
0.3
%
Dropout Voltage
∆VREF=1%
1.1
1.2
1.2
V
Current Limit
IOUT(MAX)
Long Term Stability
VIN=7V
1.4V≤ (VIN- VOUT) (Note3)
TA=125°C, 1000 Hrs.
0.3
(Note 2)
1
1
%
Thermal Regulation
(∆VOUT(Pwr))
Temperature Stability
(∆VOUT(T))
Output Noise, RMS
Thermal Resistance
TA=25°C, 20 ms pulse
0.01
0.020
0.020
%/W
All Voltage Options
Reference Voltage (VREF)
Min. Load Current (Note 3)
Line Regulation (∆VREF(VIN))
Load Regulation(∆VREF(IOUT))
IOUT =1.5A (Note 3)
IOUT≤ 1.5A (Note 2)
V
A
2.5
1.7
1.7
0.25
10Hz to 10khz
TO-220
DD Package
TA=25°C
%
0.003
Junction to Tab
Junction to Ambient
Junction to Tab
Junction to Ambient
% VO
3.0
60
3.0
60
3.0
60
3.0
60
°C/W
°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: Fixed Version Only
Note 3: Adjustable Version Only
Rev. 10/11/00
AS2815
APPLICATION HINTS
The AS2815 incorporates protection against over-current
faults, reversed load insertion, over temperature operation, and
positive and negative transient voltage. However, the use of
an output capacitor is required in order to insure the stability
and the performances.
Reducing parasitic resistance and inductance
One solution to minimize parasitic resistance and inductance is
to connect in parallel capacitors. This arrangement will
improve the transient response of the power supply if your
system requires rapidly changing current load condition.
Stability
The output capacitor is part of the regulator’s frequency
compensation system. Either a 22µF aluminum electrolytic
capacitor or a 10µF solid tantalum capacitor between the
output terminal and ground guarantees stable operation for all
operating conditions.
However, in order to minimize overshoot and undershoot, and
therefore optimize the design, please refer to the section
‘Ripple Rejection’.
Thermal Consideration
Although the AS2815 offers some limiting circuitry for
overload conditions, it is necessary not to exceed the
maximum junction temperature, and therefore to be careful
about thermal resistance. The heat flow will follow the lowest
resistance path, which is the Junction-to-case thermal
resistance. In order to insure the best thermal flow of the
component, a proper mounting is required. Note that the case
of the device is electrically connected to the output. In case
the case has to be electrically isolated, a thermally conductive
spacer can be used. However do not forget to consider its
contribution to thermal resistance.
Ripple Rejection
Ripple rejection can be improved by adding a capacitor
between the ADJ pin and ground. When ADJ pin bypassing is
used, the value of the output capacitor required increases to its
maximum (22µF for an aluminum electrolytic capacitor, or
10µF for a solid tantalum capacitor). If the ADJ pin is not
bypass, the value of the output capacitor can be lowered to
100µF for an electrolytic aluminum capacitor or 4.7µF for a
solid tantalum capacitor.
However the value of the ADJ-bypass capacitor should be
chosen with respect to the following equation:
C = 1 / ( 6.28 * FR * R1 )
Where C
= value of the capacitor in Farads (select an
equal or larger standard value),
FR = ripple frequency in Hz,
R1 = value of resistor R1 in Ohms.
Assuming:
VIN = 10V, VOUT = 5V, IOUT = 1.5A, TA = 50°C/W,
θ Heatsink Case = 6°C/W, θ Heatsink Case = 0.5°C/W, θ JC = 3°C/W
Power dissipation under this condition
PD = (VIN – VOUT) * IOUT = 7.5W
Junction Temperature
TJ = TA + PD * (θ Case – HS + θ HS + θ JC)
For Control & Power Sections
TJ = 50 + 7.5*(0.5+6=3) = 121.25°C
121.25°C < TJ (max) for Control & Power Sections.
In both case reliable operation is insured by adequate junction
temperature.
If an ADJ-bypass capacitor is use, the amplitude of the output
ripple will be independent of the output voltage. If an ADJbypass capacitor is not used, the output ripple will be
proportional to the ratio of the output voltage to the reference
voltage:
M = VOUT / VREF
Where M = multiplier for the ripple seen when the ADJ pin
is optimally bypassed.
VREF = Reference Voltage
Rev. 10/11/00
AS2815
Basic Adjustable Regulator
VOUT
VOUT
AS2815
AS2815
R1
VREF
I
VIN
5V
C1
10uF
C1
10uF
ADJ
VOUT
3.3V
50µA
R2
Basic Fixed Regulator
VOUT = VREF * ( 1 + R2/R1) + IADJ * R2
Fig.2 Basic Adjustable Regulator
Output Voltage
Consider Figure 2. The resistance R1 generates a constant
current flow, normally the specified load current of 10mA.
This current will go through the resistance R2 to set the overall
output voltage. The current IADJ is very small and constant.
Therefore its contribution to the overall output voltage is very
small and can generally be ignored.
Output Voltage
The fixed voltage LDO voltage regulators are simple to use
regulators since the VOUT is preset to the specifications. It is
important however, to provide the proper output capacitance
for stability and improvement. For most operating conditions
a capacitance of 22uF tantalum or 100uF electrolytic will
ensure stability and prevent oscillation.
Load Regulation
Parasitic line resistance can degrade load regulation. In order
not to affect the behavior of the regulator, it is best to connect
directly the R1 resistance from the resistor divider to the case,
and not to the load. For the same reason, it is best to connect
the resistor R2 to the Negative side of the load.
VOUT
R P Parasitic Line
Resistance
AS2815
Connect R 1 to
Case of Regulator
R1
RL
R2
Connect R 2 to Load
Fig.3 Basic Adjustable Regulator
Rev.10/11/00
AS2815
TYPICAL APPLICATIONS
VIN
IN
VIN
AS2815
LOAD
Fig. 5 Typical Adjustable Regulator
5V
IN
+
10µF
AS2815
*C 1 improves ripple rejection. Xc
should be ~ R 1 at ripple frequency.
VOUT
OUT
ADJ
R2
VOUT = VREF (1 + R2 ) + IADJ R2
R1
Fig. 4 1.5A Current output Regulator
(Note A)
R1
ADJ
R1
ADJ
VOUT
OUT
C2
C1
C1
VIN
AS2815
IN
OUT
VIN
+
150µF
+
C1
10µF*
AS2815
TTL
Input
5V
OUT
121Ω
1%
ADJ
R1
121Ω
1%
R2
365Ω
1%
IN
(Note A)
+
10µF
100µF
1k
2N3904
1k
365Ω
1%
Note A: VIN(MIN) = (Intended VOUT) + (VDROPOUT (MAX))
Note A: VIN(MIN)= (Intended VOUT) + (VDROPOUT (MAX))
Fig. 6
Improving Ripple Rejection
Fig.7 5V Regulator with Shutdown
Rev. 10/11/00
AS2815
TYPICAL CHARACTERISTICS
Rev. 10/11/00
AS2815
PACKAGE DRAWING
TO-263-3L (T)
0.405 ± 0.005
(10.287 ± 0.127)
0.176± 0.005 (4.470 ± 0.127)
0.050 ± 0.002 (1.270 ± 0.051)
0.055 (1.397)
0.356 ± 0.005
(9.042 ± 0.127)
0.600 +- 0.025
(15.24 ± 0.635)
0.103 BSC
(2.616)
0.050 (1.270)
0.032 +- 0.001
(0.813 +- 0.025)
0.015
(0.381
++-
0° 8°
0.003
0.074)
0.100
(2.540
±
±
0.010
0.254)
Rev. 10/11/00
AS2815
PACKAGE DRAWING
TO-220-3L (U)
0.151D ± 0.002
(3.835 D ± 0.051)
0.180 ± 0.005
(4.572 ± 0.127)
0.408 ± 0.013
(10.36 ± 0.33)
0.110 ± 0.010
(2.794 ± 0.254)
0.050 ± 0.002
(1.270 ± 0.051)
0.250 ± 0.010
(6.350 ± 0.254)
Tapered 1o
2 Sides
0.340 ± 0.010
(8.636 ± 0.254)
SEATING PLANE
1.020 ± 0.015
(25.910 ± 0.381)
0.150 MIN
(3.81 MIN)
7o Typ.
0.540 ± 0.015
(13.720 ± 0.381)
0.050 TYP
(1.27 TYP)
0.200 ± 0.010
(5.080 ± 0.254)
0.410
(10.41)
0.015 ± 0.010/-0.015
(2.667± 0.254/-0.381)
0.100 ± 0.010
(2.540 ± 0.254)
0.032 ± 0.005
(0.813 ± 0.127)
0.015 ± 0.010/-0.002
(0.381± 0.254/-0.051)
Rev. 10/11/00
AS2815
PACKAGE DRAWING
TO252-3L (R)
-A-
E
b2
-B-
A
A1
C1
L2
A
4
SEATING
PLANE
D
1
2
L3
L1
3
H
L
-C-
b
.010
M
A M
c
b1
3 PLCS
C
A
8
e
e1
NOTES
D1
E1
TERM 4
BACK VIEW A-A
1.
2.
3.
4.
Refer To Applicable Symbol List.
Dimensions And Tolerancing Per Ansi Y14.5m - 1982.
Lead Dimension Uncontrolled in L 3.
Tab Contour Optional Within Dim. b 2 & L2 And E1 & D1
5. D1 & E1 Establishes A Minimum Mounting Surface for Terminal 4.
6. L is the Termal Length for Soldering.
7. Controlling Dimension: Inch
8. 2 Mils Suggested For Postive Contact At Mounting.
S
Y
M
B
O
L
MIN
MAX
MIN
MAX
A
0.086
0.094
2.184
2.3876
INCHES
MM
A1
0.035
0.045
0.889
1.143
b
0.025
0.035
0.635
0.889
b1
0.300
0.045
7.620
1.143
b2
0.205
0.215
5.207
5.461
c
0.018
0.023
0.457
0.5842
c1
0.018
0.023
0.457
0.5842
D
0.235
0.245
5.969
6.223
D1
0.170
-
4.318
-
E
0.250
0.265
6.350
6.731
E1
0.170
-
4.318
e
0.098
e1
N
O
T
E
4
4,5
-
4,5
2.489
0.180
4.572
H
0.370
0.410
9.398
L
0.020
-
0.508
10.414
-
L1
0.025
0.040
0.635
1.016
L2
0.035
0.050
0.889
1.270
4
L3
0.045
0.060
1.143
1.524
3
6
Rev. 10/11/00