APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
This datasheet contains new product information. Advanced Power Electronics 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.
200801073-1/7
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1. Features
• 1.4V maximum dropout at full load current
• Built-in thermal shutdown
• Output current limiting
• Adjustable output voltage or fixed 1.2V, 1.5V,
1.8V, 2.5V, 3.3V, 5.0V
• Fast transient response
• Good noise rejection
• Package : TO252, TO263, TO220
• RoHS Compliant
Ordering Information
General Description
APE1085 is a low dropout positive adjustable or
fixed-mode regulator with minimum of 3.0A 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.
APE1085 is also well suited for other applications
such as VGA cards. APE1085 is guaranteed to have
lower than 1.4V dropout at full load current making it
ideal to provide well-regulated outputs of 1.25 to
3.3V with 4.7 to 12V input supply.
Block Diagram
3
Thermal
Shutdown 1
2 Vout
Adj
1.25V +
+
CURRENT
LIMIT
Vin
－
+
－
+
APE 1085 X - XX
Low Dropout Regulator Package Vout
H : TO 252-3L
S : TO 263-3L
P : TO 220-3L
Blank : Adj
15 = 1.5V
18 = 1.8V
25 = 2.5V
33 = 3.3V
50 = 5.0V
Advanced Power
Electronics Corp.
12 = 1.2V
(1.2V)
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
2/7
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Connection Diagram
TO263
3
2
1
Vin
Vout
Adj (GND)
Tab is Vout
FRONT VIEW
TO252
3
2
1
Vin
Vout
Adj (GND)
Tab is Vout
FRONT VIEW
TO220
Tab is Vout
3Vin
2
1
Vout
Adj (GND)
FRONT VIEW
Pin Descriptions
Pin No.
Name
I/O Function
Adj
(GND) I 1
Adjustable (Ground only for fixed mode)
A resistor divider from this pin to the Vout pin and ground sets the
output voltage. (Ground only for Fixed-Mode)
Vout O 2
The output of the regulator. A minimum of 10uF (0.15Ω ≤ ESR ≤
20Ω) capacitor must be connected from this pin to ground to insure
stability.
Vin I 3
The input pin of regulator. Typically a large storage capacitor (0.15
Ω
≤ ESR ≤ 20Ω) is connected from this pin to ground to insure that th
e
input voltage does not sag below the minimum dropout voltag
e
during the load transient response. This pin must always be 1.4
V
(1.3V) higher than Vout in order for the device to regulate properly.
Advanced Power
Electronics Corp.
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
3/7
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Absolute Maximum Ratings
Symbol Parameter Rating Unit
Vin DC Supply Voltage -0.3 to 12 V
PD Power Dissipation Internally Limited
TST Storage Temperature -65 to +150 oC
TOP Operating Junction Temperature Range 0 to +150 oC
Electrical Characteristics (Under Operating Conditions)
Sym. Parameter Conditions (Notes) Min. Typ. Max. Unit
VREF Reference Voltage Io=10mA, Tj=25oC, (Vin-Vout)=1.5V 1.225 1.250 1.275 V
APE1085-XXX IO=10mA, VOUT+1.5V<VIN<12V, TJ =25oC 0.2 0.5 %
APE1085-15 IOUT = 10mA, TJ = 25oC, 3V≦VIN≦12V 1.470 1.500 1.530 V
APE1085-18 IOUT = 10mA, TJ = 25oC, 3.3V≦VIN≦12V 1.764 1.800 1.836 V
APE1085-25 IOUT = 10mA, TJ = 25oC, 4V≦VIN≦12V 2.450 2.500 2.550 V
APE1085-33 IOUT = 10mA, TJ = 25oC, 4.8V≦VIN≦12V 3.235 3.300 3.365 V
Line
Regulation
APE1085-50 IOUT = 10mA, TJ = 25oC, 6.5V≦VIN≦12V 4.900 5.000 5.100 V
APE1085-Adj VIN=3.3V, 0mA<Io<3A, TJ =25oC
(Note 1,2) 1 %
APE1085-15 VIN=3V, 0mA<Io<3A, TJ =25oC
(Note 1,2) 12 15 mV
APE1085-18 VIN=3.3V, 0mA<Io<3A
TJ =25oC (Note 1,2) 15 18 mV
APE1085-25 VIN=4V, 0mA<Io<3A
TJ =25oC (Note 1,2) 20 25 mV
APE1085-33 VIN = 5V, 0mA<Io<3A , TJ=25oC (Note 1,2) 26 33 mV
Load
Regulation
APE1085-50 VIN = 8V, 0mA<Io<3A, TJ=25oC (Note 1,2) 40 50 mV
∆Vo Dropout Voltage Io=3.0A (∆Vout = 1% Vout) 1.3 1.4 V
Current Limit Vin-Vout=5V 5.1 A
Minimum Load
Current 5 10 mA
Temperature
Stability Io=10mA 0.5 %
Thermal Resistance
Junction-to-Ambient
(No heat sink ;No
air flow)
TO-252
TO-263
TO-220
98
83
83
θJA
OC/W
θJC Thermal Resistance
Junction-to-Case
TO-252: Control Circuitry/Power Transistor
TO-263: Control Circuitry/Power Transistor
TO-220: Control Circuitry/Power Transistor
10
0.65/2.7
0.65/2.7
OC/W
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 between input and output and the output current. Guaranteed maximum power dissipation will not be available over the
full input/output range.
Advanced Power
Electronics Corp.
APE1085-12 VIN=3V, 0mA<Io<3A, TJ =25oC
(Note 1,2) 10 12 mV
APE1085-12 IOUT = 10mA, TJ = 25oC, 3V≦VIN≦12V 1.176 1.200 1.224 V
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
4/7
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Typical Circuit
(1) TO263/252/220
5.0V to 3.3V Fixed Mode Regulator
C2
100uF
5V
3.3V/5A
Tab is Vout
Vin
Vout
GND
C1
100uF
Adjustable Regulator
R1
R2
C2
100uF
5V
2.5V/5A
Tab is Vout
Vin
Vout
Adj
C1
100uF
121
121
Ω
Ω
)
R1
R2
(1VREF
VO+∗=
Note:
3.3V/3A 2.5V/3A
Advanced Power
Electronics Corp.
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
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Functional Description
Introduction
The APE1085 adjustable Low Dropout (LDO) regulator
is a 3 terminal device that can easily be programmed
with the addition of two external resistors to any
voltages within the range of 1.25V to Vin-1.4V. The
APE1085 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 3.0A load step.
The APE1085 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.
Output Voltage Setting
The APE1085 can be programmed to any voltages in
the range of 1.25V to Vin-1.4V with the addition of R1
and R2 external resistors according to the following
formula:
The APE1085 keeps a constant 1.25V between the
output pin and the adjust pin. By placing a resistor R1
across these two pins a constant current flows through
R1, adding to the Iadj current and into the R2 resistor
producing a voltage equal to the (1.25/R1)*R2+Iadj*R2
which will be added to the 1.25V to set the output
voltage. This is summarized in the above equation.
Since the minimum load current requirement of the
APE1085 is 10mA, R1 is typically selected to be 121Ω
resistor so that it automatically satisfies the minimum
current requirement. Notice that since Iadj is typically
in the range of 55uA it only adds a small error to the
output voltage and should only be considered when a
very precise output voltage setting is required. For
example, in a typical 3.3V application where R1=121Ω
and R2=200Ω the error due to Iadj is only 0.3% of the
nominal set point.
Load Regulation
Since the APE1085 is only a 3 terminal device, it is not
possible to provide true remote sensing of the output
voltage at the load. The best load regulation is
achieved when the bottom side of R2 is connected to
the load and the top-side of R1 resistor is connected
directly to the case or the Vout pin of the regulator and
not to the load. It is important to note that for high
current applications, this can re-present a significant
percentage of
the overall load regulation and one must keep the path
from the regulator to the load as short as possible to
minimize this effect.
Stability
The APE1085 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 APE1085 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 150oC, 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.
Vout = Vref (1+ R2/R1) +Iadj *R2 , where Vref = 1.25 typically, Iadj =
55uA typically R1&R2 as shown at below
APE1084
Vin Vout
Vref
Adj R1
R2
Iadj=55uA
APE1085
Advanced Power
Electronics Corp.
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
6/7
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Performance Characteristics
Temperature (
o
C)
Percent Change in Output Voltage vs Temperature
Output Voltage Change (%)
-50 -25 0 25 50 75 100 125 150
- 2
-1.5
- 1
-0.5
0
0. 5
1
1.5
2
Input Voltage (V)
Line Regulation
Output Voltage Deviation (%)
0
0.2
0.4
0.6
0.8
1
24
6 8 10 12
TIME (us)
Line Transient Response
Output Voltage Deviation (mV) Input Voltage (V)
-40
-20
0
20
40
5.5
6.5
7.5 Cin=1uF
Cout=10uF Tantalum
0 20 40 60 80 100 120 140 160 180 200
TIME (us)
Load Transient Response
Load Current (A) Output Voltage Deviation (mV)
010
20 30 40 50 60 70 80 90 100
0
2
4
6
-40
-20
0
20
40
60 Cin=1uF
Cout=10uF Tantalum
Preload=100mA
Output Current (A)
Dropout Voltage vs Output Current
Dropout Voltage (V)
0
0. 2
0. 4
0. 6
0. 8
1. 0
1. 2
1. 4
1. 6
1. 8
2. 0
01234
Tj = 125
o
C
Tj = 25
o
C
5
Temperature (
o
C)
Load Regulation vs Temperature
Output Voltage Deviation (%)
-25 0 25 50 75 100 125
- 1
-0.80
-0.40
-0.20
0
0.20
I load=1.5A
Advanced Power
Electronics Corp.
APE1085
3A Low Dropout Positive Adjustable or Fixed-Mode Regulator
Advanced Power Electronics Corp.
www.a-power.com.tw
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Marking Information
(TO220-3L / TO263-3L / TO252-3L)
Part Number
Logo
1085 for ADJ
1085-VV :
15 fo
r
1. 5 V
18 fo
r
1. 8 V
25 fo
r
2. 5 V
33 fo
r
3. 3 V
50 fo
r
5V
Y: Year -“1＂: 2001 ~
WW : Xth week - ~52
SSS : Sequence - 001 ~
( Top View )
1085-VV
Y WW SSS
01
Advanced Power
Electronics Corp.
12 for 1.2V
Package Outline : TO-252
Millimeters
MIN NOM MAX
A2 1.80 2.30 2.80
A3 0.40 0.50 0.60
B1 0.40 0.70 1.00
D 6.00 6.50 7.00
D1 4.80 5.35 5.90
E3 3.50 4.00 4.50
E3 F 2.20 2.63 3.05
F1 0.5 0.85 1.20
E1 5.10 5.70 6.30
E2 0.50 1.10 1.80
e -- 2.30 --
C 0.35 0.50 0.65
1.All Dimensions Are in Millimeters.
2.Dimension Does Not Include Mold Protrusions.
Part Marking Information & Packing : TO-252
SYMBOLS
ADVANCED POWER ELECTRONICS CORP.
e
e
D
D1
E2
E1
F
B1 F1
A2
A3 C
R : 0.127~0.381
(
0.1mm
Part Number
VOUT
1085-VV
YWWSSS Date Code (YWWSS)
Y：Last Digit Of The Year
WW：Week
SSS：Sequence
LOGO
Package Outline : TO-220
Millimeters
MIN NOM MAX
A 4.25 4.48 4.70
b0.65 0.80 0.90
b1 1.15 1.38 1.60
c0.40 0.50 0.60
c1 1.00 1.20 1.40
E 9.70 10.00 10.40
E1 --- --- 11.50
e---- 2.54 ----
L 12.70 13.60 14.50
L1 2.60 2.80 3.00
L2 1.00 1.40 1.80
L3 2.6 3.10 3.6
L4 14.70 15.50 16
L5 6.30 6.50 6.70
φ3.50 3.60 3.70
D 8.40 8.90 9.40
1.All Dimensions Are in Millimeters.
2.Dimension Does Not Include Mold Protrusions.
Part Marking Information & Packing : TO-220
SYMBOLS
ADVANCED POWER ELECTRONICS CORP.
E
b
b1
e
D
L3
L4
L1
L2
A
c1
c
L
VOUT
Part Number
Date Code (YWWSSS)
Y：Last Digit Of The Year
WW：Week
SSS：Se
q
uence
1085-VV
YWWSSS
LOGO
φ
L5
E1
Package Outline : TO-263
Millimeters
MIN NOM MAX
A 4.25 4.75 5.20
A1 0.00 0.15 0.30
A2 2.20 2.45 2.70
b 0.70 0.90 1.10
b1 1.07 1.27 1.47
c 0.30 0.45 0.60
c1 1.15 1.30 1.45
D 8.30 8.90 9.40
E 9.70 10.10 10.50
e 2.04 2.54 3.04
L2 ----- 1.50 -----
L3 4.50 4.90 5.30
L4 ----- 1.50 ----
1.All Dimensions Are in Millimeters.
2.Dimension Does Not Include Mold Protrusions.
Part Marking Information & Packing : TO-263
SYMBOLS
ADVANCED POWER ELECTRONICS CORP.
VOUT
Part Numbe
r
E
b
b1
e
D
L2
L3
c1
A
θ
A1
L4
c
XXXXXS
YWWSSS
A2
Y：Last Digit Of The Year
WW：Week
SSS：Sequence
Part Numbe
r
1085-VV
YWWSSS LOGO
E
b
b1
e
D
L2
L3
c1
A
θ
A1
L4
c
A2
Date Code (YWWSSS)
Y：Last Digit Of The Year
WW：Week
SSS：Sequence
