Diodes AP1084 User Manual

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

Features

• 1.4V Maximum Dropout at Full Load Current

• Built-in Thermal Shutdown

• Output Current Limiting

• Adjustable Output Voltage or Fixed 1.5V, 1.8V, 2.5V,

3.3V, 5.0V

• Fast Transient Response

• Good Noise Rejection

• Lead Free Packages: TO252-3L, TO263-3L and

TO220-3L

• TO252-3L, TO263-3L and TO220-3L: Available in
“Green” Molding Compound (No Br, Sb)

• Lead Free Finish/RoHS Compliant (Note 1)

Typical Application Circuit

5.0V to 3.3V Fixed Mode Regulator

5V

V

C1

100uF

in

General Description

AP1084 is a low dropout positive adjustable or fixed-mode
regulator with 5.0A 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. AP1084 is also well suited for other
applications such as VGA cards. AP1084 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.

Adjustable Regulator

5V

V

C1

100uF

in

2.5V/5A

C2
100uF

Tab is V

V

out

GND

out

C2

100uF

3.3V/5A

Tab is V

Note:

V

out

Adj

out

121
121

(1 V

Ω

Ω

R

2

)

+∗=

R

1

R1
R2

V

REF

O

AP1084 Rev. 9 1 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

Ordering Information

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

AP1084 X XX X - X

AP1084

FIXED-MODE REGULATOR

Package Vout

D : TO252-3L

Blank = Adj
K : TO263-3L
T : TO220-3L

15 = 1.5V
18 = 1.8V

Lead Free

L : Lead Free

G : Green

Packing

U : Tube

13 : Tape & Reel

25 = 2.5V
33 = 3.3V
50 = 5.0V

Device

AP1084DXXL-13 D TO252-3L NA NA 2500/Tape & Reel -13
AP1084DXXG-13 D TO252-3L NA NA 2500/Tape & Reel -13
AP1084KXXL-13 K TO263-3L NA NA 800/Tape & Reel -13
AP1084KXXG-13 K TO263-3L NA NA 800/Tape & Reel -13
AP1084TXXL-U T TO220-3L 50 -U NA NA
AP1084TXXG-U T TO220-3L 50 -U NA NA

Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at

http://www.diodes.com/datasheets/ap02001.pdf.

http://www.diodes.com/products/lead_free.html.

2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at

Package

Code

Packaging

(Note 2)

Quantity

Tube 13” Tape and Reel

Part Number

Suffix

Quantity

Part Number

Suffix

AP1084 Rev. 9 2 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

Pin Assignment

(1) TO252-3L (2) TO263-3L

( Top View )

3

2

V

IN

V

OUT

AP1084

FIXED-MODE REGULATOR

( Top View )

3

2

V

IN

V

OUT

1

Tab is V

(3) TO220-3L

OUT

Adj (GND)

( Top View)

3
2

1

Tab is V

OUT

V

IN

V

OUT

Adj (GND)

Pin Description

Pin Name I/O Pin # Description

Adjustable (Ground only for fixed mode)

Adj (GND) I 1

A resistor divider from this pin to the V
(Ground only for Fixed-Mode).

pin and ground sets the output voltage

OUT

1

Tab is V

OUT

Adj (GND)

V

O 2

OUT

VIN I 3

AP1084 Rev. 9 3 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

The output of the regulator. A m inimum of 10uF (0.15Ω ≤ ESR ≤ 20Ω) 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
(1.3V) higher than V

in order for the device to regulate properly.

OUT

Block Diagram

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

3

V

in

2

V

out

+

-

+

1.25V

+

CURRENT

LIMIT

+

Thermal

Shutdown

-

1

Adj

Absolute Maximum Ratings

Symbol Parameter Rating Unit

VIN DC Supply Voltage -0.3 to 12 V
TST Storage Temperature -65 to +150

TMJ Maximum Junction Temperature 150

Recommended Operating Conditions

Symbol Parameter

TOP Operating Junction Temperature Range

Min Max

0 125

o

C

oC

Unit

oC

AP1084 Rev. 9 4 of 11 JANUARY 2010
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AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

Electrical Characteristics (Under Operating Conditions)

Symbol

V

REF

Line

Regulation

Load

Regulation

ΔVo

Current Limit VIN-V

Parameter

Reference
Voltage
AP1084-XXX I

AP1084-1.5
AP1084-1.8
AP1084-2.5
AP1084-3.3
AP1084-5.0
AP1084-Adj V

AP1084-1.5
AP1084-1.8
AP1084-2.5

AP1084-3.3 V
AP1084-5.0
Dropout

Voltage
Minimum Load

Current
Temperature
Stability

Io = 10mA, TA = 25oC, (VIN-V

= 10mA, V

O

= 10mA, TA = 25oC, 3V≦VIN≦12V

I

OUT

= 10mA, TA = 25oC, 3.3V≦VIN≦12V

I

OUT

= 10mA, TA = 25oC, 4V≦VIN≦12V

I

OUT

= 10mA, TA = 25oC, 4.8V≦VIN≦12V

I

OUT

= 10mA, TA = 25oC, 6.5V≦VIN≦12V

I

OUT

= 3.3V, 0mA<Io<5A, TA = 25oC 1 %

IN

= 3V, 0mA<Io<5A, TA = 25oC

V

IN

(Note 3, 4)
V

= 3.3V, 0mA<Io<5A

IN

T

= 25oC (Note 3, 4)

A

V

= 4V, 0mA < Io < 5A

IN

T

= 25oC (Note 3, 4)

A

= 5V, 0mA < Io < 5A, TA= 25oC (Note 3, 4) 26 33 mV

IN

V

= 8V, 0mA < Io < 5A, TA = 25oC

IN

(Note 3, 4)
I

= 5.0A (ΔV

o

= 5V 5.1 A

OUT

Io = 10mA 0.5 %

Thermal

TSD

Shutdown
Temperature
Thermal
Resistance

θ

Junction-to-

JA

Ambient
(Note 5)

Thermal

JC

Resistance
Junction-to-

θ

Case (Note 5)

Notes: 3. See t hermal 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.

4. 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.

5. Test conditions for TO220-3L, TO252-3L and TO263-3L: Devices mounted on FR-4 substrate, single sided PC board, 2oz copper, with minimum

recommended pay layout, no air flow. The case point of θ

TO220-3L 78
TO252-3L 73

TO263-3L 60
TO220-3L:Control Circuitry/Power Transistor 3.5

TO252-3L:Control Circuitry/Power Transistor 12
TO263-3L:Control Circuitry/Power Transistor 3.5

Conditions Min Typ. Max Unit

) = 1.5V 1.225 1.250 1.275 V

OUT

+1.5V<VIN<12V, TA = 25oC 0.2 %

OUT

1.470 1.500 1.530 V

1.764 1.800 1.836 V

2.450 2.500 2.550 V

3.235 3.300 3.365 V

4.900 5.000 5.100 V

12 15 mV
15 18 mV
20 25 mV

40 50 mV

= 1% V

OUT

OUT

)

1.3 1.4 V

5 10 mA

150 OC

O

C/W

O

C/W

is located on the thermal tab.

JC

AP1084 Rev. 9 5 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

Functional Description

Introduction
The AP1084 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 AP1084 only needs 1.4V differential between V
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 5.0A load step.
The AP1084 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 AP1084 can be prog ramm ed to a ny v oltages in the rang e of 1.25V to Vin-1.4V with th e additio n of R1 and R 2 ext ernal resistors
according to the following formula:

V

= V

out

(1+ R2/R1) +I

ref

*R2 , where V

adj

= 1.25 typically, I

ref

adj

=

55uA typically R1 & R2 as shown below:

and V

IN

OUT

V

in

AP1084

Adj

I

adj

= 55uA

V

ref

R1

V

out

R2

The AP1084 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 curre nt requirem ent of the AP108 4 is 10mA, R1 is typic ally selecte d to be 121 Ω 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 AP1084 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 V
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 AP1084 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 AP1084 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
recommended that the selected heat sink be chosen such that during maximum continuous load operation the junction temperature is
kept below that temperature.

Layout Consideration

The output capacitors must be located as close to the V
of a layer of the PC board as a plane to connect the V
result due to excessive trace inductance.

pin of the regulator and not to the load. It is important to note that for high current application s, this can re-p resen t

OUT

terminal of the device as possible. It is recommended to use a section

OUT

pin to the output capacitors to prevent any high frequency oscillation that may

OUT

o

C, it is

AP1084 Rev. 9 6 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

Output Vol

t

C

D

t Vol

t

V

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

Typical Performance Characteristics

2. 0

1. 8

1. 6

1. 4

)

1. 2

age (

1. 0

0. 8

0. 6

ropou

0. 4

0. 2

0

0

Dropout Voltage vs Output Current

Tj = 25 oC

1234

Output Current (A)

Tj = 125 oC

5

FIXED-MODE REGULATOR

0.20

-0.20

-0.40

-0.80

Output Voltage Deviation (%)

0

- 1

-40 0

I load=1.5A

25 50 75 100 125

Temperature (oC)

Load Regulation vs Temperature

AP1084

2

1.5

1

0. 5

hange (%)

0

-0.5

age

- 1

-1.5

- 2

-40 -25 0 25 50 75 100 125 150

Percent Change in Output Voltage vs Temperature

7.5
Cin=1uF
Cout=10uF Tantalum

6.5

5.5

40

20

0

-20

-40

0 20 40 60 80 100 120 140 160 180 200

Output Voltage Deviation (mV) Input Voltage (V)

Temperature (oC)

TIME (us)

Line Transient Response

1

0.8

0.6

0.4

0.2

Output Voltage Deviation (%)

0

24

60

40

20

0

-20

-40

Output Voltage Deviation (mV)

6

4

2

0

010

Load Current (A)

681012

Input Voltage (V)

Line Regulation

Cin=1uF
Cout=10uF Tantalum
Preload=100mA

20 30 40 50 60 70 80 90 100

TIME (us)

Load Transient Response

AP1084 Rev. 9 7 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

Marking Information

(1) TO252-3L

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

( Top view )

(2) TO263-3L

(3) TO220-3L

Logo

Part Number
1084 for ADJ
84-VV : 15 for 1.5V
18 for 1.8V
25 for 2.5V
33 for 3.3V
50 for 5.0V

Logo

Part Number

VV: 15 for 1.5V
18 for 1.8V
25 for 2.5V
33 for 3.3V

50 for 5.0V

Blank for ADJ

84-VV
YY WW X X

( Top view )

1084-VV
YY WW X

X

L : Lead Free
G : Green

YY

: Year : 01~09

: Week : 01~52, 52 represents

WW

52 and 53 week

: Internal Code

X

L : Lead Free
G : Green

: Year : 01~09

YY
WW

: Week : 01~52, 52 represents

52 and 53 week

X : Internal code

( Top view )

Logo

Part Number
VV: 15 for 1.5V

18 for 1.8V
25 for 2.5V
33 for 3.3V

50 for 5.0V

Blank for ADJ

1084-VV
YY WW X X

AP1084 Rev. 9 8 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

L : Lead Free

G : Green
YY : Year : 01~09

: Week : 01~52, 52 represents

WW

52 and 53 week

X : Internal code

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

Package Information (All Dimensions in mm)

(1) Package type: TO252-3L

6.354/6.80 Typ 6.58

5.20/5.50 Typ 5.35

0.88/1.27

AP1084

FIXED-MODE REGULATOR

5.6

5.6

0.61 Typ

(2) Package type: TO263-3L

9.65/10.29 Typ 9.97

2.28

BSC.

4.57 BSC.

5.40/6.20

0.64/1.02
Typ 0.83

0.45/0.58
Typ 0.52

2.92
Typ 1.30

8.65/9.65 Typ 9.15

14.61/15.88 Typ 15.24

Typ 5.57

11.0

2.25

2.0

7.2

Land Pattern Recommendation (Unit: mm)

0.89/

1.14

9.00/10.40 Typ 9.70

0.51

9.1

SEATING

SEE NOTE2

PLANE

10.9

0.45/0.58
Typ 0.52

3

1.2

2.18/2.40
Typ 2.29

15.7

2.54

BSC.

Typ

1.78

1.52

1.27/

0.51/0.99 Typ 0.75

1.14/1.40 Typ1.27

2.28/2.80 Typ 2.54

1.3

Land Pattern Recommendation (Unit: mm)

0.38 Typ

2.54

Typ 4.45

4.06/4.83

Typ 1.27

1.14/1.40

AP1084 Rev. 9 9 of 11 JANUARY 2010
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Package Information (Continued)

(3) Package type: TO220-3L

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

2.54/3.43
Typ 2.98

14.20/16.50

1.14/1.78
Typ 1.46

4.83/5.33
Typ 5.08

Typ 15.35

9.70/10.70
Typ 10.20

∅

3.66/6.35
Typ 5.00

0.51/1.14
Typ 0.83

2.99/2.79
Typ 2.54

3.53/4.09
Typ 3.81

5.84/6.86
Typ 6.35

Typ 13.72

12.72/14.72

0.31/1.14
Typ 0.72

3.55/4.85
Typ 4.20

2.03/2.92
Typ 2.48

0.51/1.40
Typ 0.95

SEATING PLANE

AP1084 Rev. 9 10 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated

AP1084

5A LOW DROPOUT POSITIVE ADJUSTABLE OR

FIXED-MODE REGULATOR

IMPORTANT NOTICE

DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDING TO THIS
DOCUMENT, INCLUDIN G, BUT NOT L IMITED TO, THE I MPLIED W ARRANTIE S OF MERCHA NTABIL ITY AND FI TNESS FOR A
PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY J URISDICTION).

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changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any
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without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:

A. Life support devices or syst ems are devices or systems which:

1. are intended to implant into the body, or

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in the labeling can be reasonably expected to result in significant injury to the user.

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to cause the failure of the life support device or to affect its safety or effectiveness.

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Copyright © 2009, Diod es Incorporated

www.diodes.com

AP1084 Rev. 9 11 of 11 JANUARY 2010
DS31070 www.diodes.com © Diodes Incorporated