SPX1581T5-2.5-L/TR [EXAR]

Fixed Positive LDO Regulator, 2.5V, 0.5V Dropout, PSSO5, LEAD FREE, TO-263, 5 PIN;


型号：	SPX1581T5-2.5-L/TR
厂家：	EXAR CORPORATION
描述：	Fixed Positive LDO Regulator, 2.5V, 0.5V Dropout, PSSO5, LEAD FREE, TO-263, 5 PIN 输出元件调节器
文件：	总7页 (文件大小：81K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SPX1581

5A Ultra Low Dropout Voltage Regulator

Fast Response, Adjustable & Fixed

FEATURES

■Low Dropout Voltage 500mV at 5A Full Load Current

■Adjustable Ouput Down to 1.2V from ATX Power Supply

■Fixed Output Voltages of 3.3V, 2.8V and 2.5V

■Extremely Tight Load and Line Regulation

SPX1581

5 Pin TO-263

SPX1581

5 Pin TO-220

2 3 4 5

■Standard 5-Terminal Low Cost TO-220 and TO-263

APPLICATIONS

■3.3V to 2.8V ATX Power Supplies

■3.3V to 2.9V for Portable PENTIUM^TMProcessor

■5V to 3.5V VRE Supply

■High efficiency "Green" Computer Systems

Now Available in Lead Free Packaging

DESCRIPTION

The SPX1581 is a 5A Low Dropout Regulator with extremely low dropout voltage. The adjustable version requires only

two external resistors to set the output voltage. The fixed version has a preset output of 3.3V, 2.8V or 2.5V and does

not require any external resistors. The SPX1581 features a low dropout of 400mV(Typ.) and offers fast transient

response. This device is suitable for Pentium applications requiring 2.8V, 2.5V from 3.3V ATX power supplies, where

a low current input voltage 1V greater than the output voltage is needed. With an external sense pin the load regulation

is less than 1mV. This device is an excellent choice for the use of powering low voltage microprocessors that require

alowerdropout,fasttransientresponsetoregulatefrom3.3Vand5Vsupplies.TheSPX1581isalsoanexcellentchoice

as a post regulator for switching supplies applications.

The SPX1581 offers protection against over-current faults, reversed input polarity, over temperature operation and

positive and negative transient voltage.

The SPX1581 is offered in a 5 pin TO-220 and TO-263 compatible with industry standard 5-terminal regulators. For

7A, 3A and 1.5A ultra low dropout versions refer to SPX1580, SPX1582 and SPX1583 data sheets respectively.

TYPICAL APPLICATIONS CIRCUIT

OUT

2.5V

OUT

3.3V

SPX1581

330µF

V_IN

V_OUT

2.5V

V_OUT

3.3V

V_IN

SPX1581

330µF

CTRL

SENSE

V_CTRL

SENSE

124Ω

ADJ

2x330µF

GND

10µF

2x330µF

10µF

.033µF

124Ω

(1) V_CTRLneeded when V_IN< 5V.

(1) V

(2) V

(3) V

needed when V < 5V.

CTRL

OUT

REF

= V

(1+R /R )+I

R .

REF

ADJ

is measured across adjust to sense.

Adjustable Regulator

Typical Fixed Regulator

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

ABSOLUTE MAXIMUM RATINGS

Input Supply Voltage ..................................................... 6V

V_CTRLInput Voltage ....................................................... 13V

Power Dissipation ..................................... Internally Limited

Lead Temp. (Soldering, 10 Seconds) ......................... 300°C

Storage Temperature Range ..................... -65°C to +150°C

Operating Junction Temperature Range

SPX1581 Control Section ............................. 0°C to +125°C

SPX1581 Power Transistor .......................... 0°C to +150°C

ELECTRICAL CHARACTERISTICS

Electrical characteristics at V_OUT= V_SENSE, V_ADJ= 0V, T_A=25°C, C_CTL= C_PWR= C_OUT= 33µF tantalum cap otherwise specified.

The ♦ denotes the specifications which apply over full temperature range -40°C to +85°C, unless otherwise specified.

PARAMETER

2.5V Version

Output Voltage

MIN

TYP MAX UNITS

♦

CONDITIONS

2.450

2.400

2.5

2.8

2.550

2.600

V_CTRL= 6.0V to 12V, V_IN= 3.0V to 5.0V, I_O=10mA

I_O= 10mA to 5A

2.8V Version

Output Voltage

2.744

2.688

2.856

2.912

V_CTRL= 6.3V to 12V, V_IN=3.3V to 12V, I_O=10mA

I_O= 10mA to 5A

3.3V Version

Output Voltage

3.234

3.168

3.3

3.366

3.432

V_CTRL= 6.3V to 12V, V_IN= 3.3V + 0.8V, I_O=10mA

I_O= 10mA to 5A

All Voltage Options

Reference Voltage

1.238 1.25 1.263

V_CTRL= 2.75V, V_IN= 2.00V, I_O= 10mA

V_CTRL=2.7V to 12V,V_IN= 2.05V to 5.5V,I_O=10mA to 5A

V_CTRL= 2.5V to 12V, V_IN= 1.75V to 5.5V, I_O=10mA

V_ADJ=0V

Line Regulation

1.0

3.0

5.0

♦

Load Regulation (Note 1)

V_CTRL= 2.75V, V_IN= 2.1V, I_O=10mA to 5A, V_ADJ= 0V

Dropout Voltage Min. V_CTRL

1.10

0.40

1.25

0.50

V_ADJ= 0V

(Note 2) (V_CTRL- V_OUT

)

V_IN= 2.05V, I_O= 1A

Dropout Voltage Min. V_IN

V_ADJ= 0V

(Note 2) (V_IN- V_OUT

)

V_IN= 2.75V, I_O= 5A

Current Limit

5.1

V_CTRL= 2.75V, V_IN= 2.05V, ∆ V_OUT= 100mV, V_ADJ= 0V

V_CTRL= 5V, V_IN=3.3V, V_ADJ=0V

Minimum Load Current

♦

Thermal Regulation

Ripple Rejection

0.002 0.02

%/W

30ms Pulse

V_CTRL= 3.75V, V_IN= 3.75V, I_O= 2.5A, V_ADJ=0V

T_J=25, V_RIPPLE=1Vpp at 120Hz

V_ADJ= 0V

Control Pin Current

120

♦

V_CTRL= 2.75V, V_IN= 2.05V, I_O= 5A

V_CTRL= 2.75V, V_IN= 2.05V, V_ADJ=0V, I_O= 10mA

Adjustble Pin Current

µA

120

Thermal Resistance

TO-220-5

°C/W

Junction to Case (θ_JC

Junction to Ambient (θ_JA

Junction to Case (θ_JC

Junction to Ambient (θ_JA

)

Thermal Resistance

TO-263-5

)

Note 1: Low duty cycle pulse testing with Kelvin connections is required to order to maintain accurate data.

Note 2: Dropout voltage is defined as the minimum differential between V_INand V_OUTor V_CTRLand V_OUTrequired to

maintain regulation at V_OUT95% Nominal V_OUT

Note 3: V_REFis measured across Adjust pin to Sense pin.

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

PIN DESCRIPTION

PIN NUMBER

PIN NAME

DESCRIPTION

SENSE

Allows Kelvin sense of V_OUTat the load. (Positive side of the reference

voltage of the device).

ADJ

Negative side of the reference voltage for the device. Adding a small

bypass capacitor from the ADJ pin to ground will improve the transient

response.

V_OUT

Power output of the device.

V_CTRL

Supply pin for the control circuitry of the device. The current flow into this

pin will be about 1% of the output current. V_CTRLmust be between 1.0V

and 1.3V greater than the output voltage for the

device to regulate.

V_IN

Output load current is supplied through this pin. V_INmust be between 0.1V

and 0.8V greater than the output voltage for this device to regulate.

FUNCTIONAL DIAGRAM

(4) V_CTRL

V_IN(5)

S.O.A

LIMIT

CURRENT

LIMIT

AMPLIFIER

V_OUT(3)

SENSE

THERMAL OVERLOAD

SENSE (1)

ADJ (2)

VOLTAGE

REGULATION

AMPLIFIER

V_REF

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

APPLICATION NOTES

Adjustable Regulator Design

The SPX1581 is designed as a high performance

and low cost solution for application requiring a

lower dropout than traditional NPN regulators.

1.25V reference voltage is being developed be-

tween the SENSE pin and the ADJ pin of the

SPX1581.Addingtwoexternalresistors(seefig

1.) will allow setting the output voltage from

1.25V to 6V. R₁is chosen so that this current is

specified minimum load current of 10mA. R₂is

given by the formula: V_OUT= V_REF(1+ R₂/R₁)

+ I_ADJ(R₂). The current flowing from the ADJ

pin is typicaly 50µA. This ADJ pin contributes

to the final V_OUTbut is usually neglected.

Connecting the sense pin to the top of the resis-

tor divider will improve load regualtion.

TheSPX1581usesaseparateinputvoltageV_CTRL

( V_CTRL≥ V_OUT+ 1.3V) to minimize the dropout

voltage. This allows the 2.5V power for the load

to come from a 3.3V system supply.

As added benefit this will reduce the heat dissi-

pation*, andlowerheatsinkandcoolingfancost.

A typical application would use 5V for V_INand

3.3V for V_CTRLfrom a motherboard power

supply to provide a nominal 2.5V output. Using

the sense pin allows Kelvin measure the output,

reducing resistance-associated errors.

Lowering Noise

Using the SENSE pin to Kelvin the load will

increase accuracy of the output voltage during

load regulation. For the fixed voltage device,

adding a capacitor at the GND pin will improve

transient response. This capacitor is chosen in

the range of 1µF to 0.1µF and will depend on the

amount of output capacitance in the system.

The SPX1581 can power the 2.5V core voltage

for microprocessors such as a Pentium

P55C , AMD5k86 and K6 and the IBM

PowerPC

603EV and 604EV processors.

Power sequencing of V_INand V_CTRLis re-

quired. Apply V_INbefore V_CTRLfor proper

operation

* The reduction of heat dissipation is a result of the

increase of the regulator efficiency (efficiency = V_OUT/V_IN).

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

PACKAGE: 5 Pin TO-220

E/2

SEATING

PLANE

øP

CHAMFER

OPTIONAL

Dimensions in

(inches)

5 PIN TO-220

MIN NOM MAX

.160

.190

.040

.022

.590

.415

.015

.014

.560

.385

.062

.415

.072

.045

.234

.090

.540

.055

.258

.115

.560

.250

∆P

.146

.156

.103

.113

5 PIN TO-220

.30

.24

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

PACKAGE: 5 Pin TO-263

SEATING PLANE

(DATUM A)

(E)

5X b

5 PIN TO-263

JEDEC TO-263

(BB) Variation

Dimensions in (mm)

MIN NOM MAX

.160

.190

.010

.039

.029

.023

.020

.015

.045

.270

0º-8º

.380

.245

.420

(b)

.067 BSC

.625

WITH PLATING

.575

.070

.110

.066

.070

.010 BSC

BASE METAL

CONTACT AREA

5 PIN TO-263

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

ORDERING INFORMATION

Output Voltage Packages

Part Number

Accuracy

SPX1581U5 ............................... 2.0%............................. Adj.......................... 5-Pin TO-220

SPX1581U5-2.5 ......................... 2.0%............................ 2.5V ........................ 5-Pin TO-220

SPX1581U5-2.8 ......................... 2.0%............................ 2.8V ........................ 5-Pin TO-220

SPX1581U5-3.3 ......................... 2.0%............................ 3.3V ........................ 5-Pin TO-220

SPX1581T5 ................................ 2.0%............................. Adj.......................... 5-Pin TO-263

SPX1581T5/TR .......................... 2.0%............................. Adj.......................... 5-Pin TO-263

SPX1581T5-2.5.......................... 2.0%............................ 2.5V ........................ 5-Pin TO-263

SPX1581T5-2.5/TR .................... 2.0%............................ 2.5V ........................ 5-Pin TO-263

SPX1581T5-2.8.......................... 2.0%............................ 2.8V ........................ 5-Pin TO-263

SPX1581T5-2.8/TR .................... 2.0%............................ 2.8V ........................ 5-Pin TO-263

SPX1581T5-3.3.......................... 2.0%............................ 3.3V ........................ 5-Pin TO-263

SPX1581T5-3.3/TR .................... 2.0%............................ 3.3V ........................ 5-Pin TO-263

Available in lead free packaging. To order add "-L" suffix to part number.

Example: SPX1581T5-3.3/TR = standard; SPX1581T5-L-3.3/TR = lead free

/TR = Tape and Reel

Pack quantity is 500 for TO-263.

Corporation

ANALOGEXCELLENCE

Sipex Corporation

Headquarters and

Sales Office

233 South Hillview Drive

Milpitas, CA 95035

TEL: (408) 934-7500

FAX: (408) 935-7600

Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the

application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.

Date 10/29/04

SPX1581 5A Ultra Low Dropout Voltage Regulator

SPX1581T5-2.5-L/TR [EXAR]

相关型号：

SPX1581T5-2.5.

SPX1581T5-2.5/TR

SPX1581T5-2.8

SPX1581T5-2.8

SPX1581T5-2.8-L/TR

SPX1581T5-2.8/TR

SPX1581T5-2.8/TR

SPX1581T5-3-3

SPX1581T5-3-3/TR

SPX1581T5-3.3

SPX1581T5-3.3

SPX1581T5-3.3-L