1.5A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Features
•
•
•
•
•
General Description
AP1086 is a low dropout positive adjustable or
fixed-mode regulator with minimum of 1.5A output
current capability. The product is specifically
designed to provide well-regulated supply for low
voltage IC applications such as high-speed bus
termination and low current 3.3V logic supply.
AP1086 is also well suited for other applications
such as VGA cards. AP1086 is guaranteed to have
<1.4V dropout at full load current making it ideal to
provide well-regulated outputs of 1.25V to 5.0V with
4.7 to 12V input supply by different output voltage.
3-Terminal Adjustable or Fixed 1.5V, 1.8V, 2.5V,
3.3V, 5.0V
1.4V Maximum Dropout at Full Load Current
Fast Transient Response
Built-in Thermal Shutdown
Output Current Limiting
Ordering Information
AP1086 X
X
X
X
Low Dropout Regulator
Package
D : TO252-3L
K : TO263-3L
T : TO220-3L
Vout
Blank : Adj
15 = 1.5V
18 = 1.8V
25 = 2.5V
33 = 3.3V
50 = 5.0V
Lead Free
Packing
Blank : Normal
Blank : Tube
L : Lead Free Package A : Taping
Typical Application
5V to 3.3V Fixed Mode Regulator
5V
C1
100uF
Vin
Vout
GND
Tab is Vout
3.3V/1.5A
C2
100uF
Vin
Vout
Adj
Tab is Vout
R1
121
Ω
R2
121
Ω
5V
Adjustable Regulator
C1
100uF
V
OUT
=V
ref
×
(1+R2/R1)
2.5V/1.5A
C2
100uF
Note:
V
o
=
V
REF
∗
(1
+
R
2
)
R
1
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev.1.3 Jun. 8, 2005
1/9
AP1086
1.5A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Block Diagram
Vin
3
2
Vout
+
+
－
1.25V
CURRENT
LIMIT
+
+
THERMAL
SHUTDOWN
1
Adj
(GND)
Connection Diagram
3 PIN TO263
FRONT VIEW
3 PIN TO252
FRONT VIEW
3
2
1
Tab is Vout
Vin
Vout
Adj
(GND)
Tab is Vout
3 PIN TO220
FRONT VIEW
3
2
1
Vin
Vout
Adj
(GND)
3
2
1
Vin
Vout
Adj
(GND)
Tab is Vout
Pin Descriptions
NAME
Adj
(GND)
Vout
O
I/O
PIN #
1
2
FUNCTION
Adjustable (Ground only for fixed mode)
The output of the regulator. A minimum of 10uF capacitor must be
connected from this pin to ground to insure stability.
The input pin of regulator. Typically a large storage capacitor is
connected from this pin to ground to insure that the input voltage does
not sag below the minimum dropout voltage during the load transient
response. This pin must always be 1.4V higher than Vout in order for
the device to regulate properly.
Vin
I
3
Anachip Corp.
www.anachip.com.tw
2/9
－
Rev.1.3 Jun. 8, 2005
AP1086
1.5A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Absolute Maximum Ratings
Symbol
Vin
P
D
T
ST
T
OP
Parameter
DC Supply Voltage
Power Dissipation
Storage Temperature
Operating Junction Temperature Range
Rating
Unit
-0.3 to 12
V
Internally Limited
o
-65 to +150
C
o
0 to +150
C
Electrical Characteristics
PARAMETER
Reference Voltage
Output Voltage
AP1086-Adj
AP1086-1.5
AP1086-1.8
AP1086-2.5
AP1086-3.3
AP1086-5.0
Line Regulation
AP1086-XXX
AP1086-Adj
AP1086-1.5
AP1086-1.8
Load Regulation
AP1086-2.5
AP1086-3.3
AP1086-5.0
Dropout Voltage
(V
IN
-V
OUT
)
Current Limit
Minimum Load Current
Thermal Regulation
Ripple Rejection
RMS Noise (% of V
OUT
)
Temperature Stability
Thermal Resistance
Junction-to-Ambient
(No heat sink ;No air flow)
Thermal Resistance
Junction-to-Case
(Under Operating Conditions)
CONDITIONS
T
J
=25 C,(V
IN
-V
OUT
)=1.5V,I
O
=10mA
o
I
OUT
= 10mA, T
J
= 25 C, 3V≦V
IN
≦12V
o
I
OUT
= 10mA, T
J
= 25 C, 3.3V≦V
IN
≦
12V
I
OUT
= 10mA, T
J
= 25
o
C, 4V≦V
IN
≦12V
I
OUT
= 10mA, T
J
= 25
o
C, 4.8V≦V
IN
≦
12V
o
I
OUT
= 10mA, T
J
= 25 C, 6.5V≦V
IN
≦
12V
I
O
=10mA, V
OUT
+1.5V<V
IN
<12V
V
IN
=3.3V, 0mA<Io<1.5A, T
J
=25
o
C
(Note 1, 2)
V
IN
=3V, 0mA<Io<1.5A, T
J
=25
o
C
(Note 1, 2)
o
V
IN
=3.3V, 0mA<Io<1.5A, T
J
=25 C
(Note 1, 2)
o
V
IN
=4V, 0mA<Io<1.5A, T
J
=25 C
(Note 1, 2)
o
V
IN
= 5V, 0≦I
OUT
≦1.5A,
T
J
=25 C ,
T
J
=25
o
C (Note 1.2)
o
V
IN
= 8V, 0≦I
OUT
≦1.5A,
T
J
=25 C ,
T
J
=25
o
C (Note 1.2)
o
MIN
1.225
1.470
1.764
2.450
3.235
4.900
-
-
-
-
-
-
-
-
1. 6
-
-
-
-
-
-
-
TYP
1.250
1.500
1.800
2.500
3.300
5.000
-
-
12
15
20
26
40
1.3
-
5
0.008
60
0.003
0.5
101
83
86
15
0.65/2.7
0.65/2.7
MAX UNIT
1.275
1.530
1.836
2.550
3.365
5.100
0.2
1
15
18
25
33
50
1.4
-
10
0.04
70
-
-
-
-
O
V
V
V
V
V
V
%
%
mV
mV
mV
mV
mV
V
A
mA
%/W
dB
%
%
C/W
C/W
AP1086-Adj/-2.5
I
OUT
= 1.5A,
∆V
OUT
=1%V
OUT
/-3.3/-3.6/-5.0
AP1086-Adj/-2.5
(V
IN
-V
OUT
) = 5V
/-3.3/-3.6/-5.0
o
o
0 C≦Tj≦125 C
AP1086-XXX
T
A
=25℃, 30ms pulse
F=120Hz,C
OUT
=25uF Tantalum, I
OUT
=1.5A
AP1086-XXX
V
IN
=V
OUT
+3V
10Hz
≤
f
≤
10KHz
I
O
=10mA
TO-252
TO-263
TO-220
TO-252: Control Circuitry/Power Transistor
TO-263: Control Circuitry/Power Transistor
TO-220: Control Circuitry/Power Transistor
O
Note 1: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at a constant
junction temperature by low duty cycle pulse testing. Load regulation is measured at the output lead = 1/18” from the package.
Note 2:Line and load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the difference in input and
output and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range.
Note 3:Quiescent current is defined as the minimum output current required in maintaining regulation. At 12V input/output differential the device is
guaranteed to regulate if the output current is greater than 10mA.
Anachip Corp.
www.anachip.com.tw
3/9
Rev.1.3 Jun. 8, 2005
AP1086
1.5A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Functional Description
Introduction
The AP1086 adjustable or fixed-mode Low Dropout
(LDO) regulator is a 3 terminal device which can
easily be programmed by internal mask change to
any voltages within the range of 1.25V to Vin-1.4V.
The AP1086 only needs 1.4V differential between
Vin and Vout to maintain output regulation. In
addition, the output voltage tolerances are also
extremely tight and they include the transient
response as part of the specification. For example,
Intel VRE specification calls for a total of +/- 100mV
including initial tolerance, load regulation and 0 to
1.5A load step.
The AP1086 is specifically designed to meet the
fast current transient needs as well as providing an
accurate initial voltage, reducing the overall system
cost with the need for fewer output capacitors.
Load Regulation
Since the AP1086 is only a 3 terminal device, it is
not possible to provide true remote sensing of the
output voltage at the load. But it can supply good
load regulation by internal feedback bypass the
external loss such as adjustable mode.
Stability
The AP1086 requires the use of an output capacitor
as part of the frequency compensation in order to
make the regulator stable. For most applications a
minimum of 10uF aluminum electrolytic capacitor
insures both stability and good transient response.
Thermal Design
The AP1086 incorporates an internal thermal
shutdown that protects the device when the junction
temperature exceeds the maximum allowable
junction temperature. Although this device can
operate with junction temperatures in the range of
150
o
C, it is recommended that the selected heat
sink be chosen such that during maximum
continuous load operation the junction temperature
is kept below the temperature.
Layout Consideration
The output capacitors must be located as close to
the Vout terminal of the device as possible. It is
recommended to use a section of a layer of the PC
board as a plane to connect the Vout pin to the
output capacitors to prevent any high frequency
oscillation that may result due to excessive trace
inductance.
Anachip Corp.
www.anachip.com.tw
4/9
Rev.1.3 Jun. 8, 2005
AP1086
1.5A Low Dropout Positive Adjustable or Fixed-Mode Regulator
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