SPX1587R-1.8 [SIPEX]

3A Low Dropout Voltage Regulator; 3A低压差稳压器


型号：	SPX1587R-1.8
厂家：	SIPEX CORPORATION
描述：	3A Low Dropout Voltage Regulator 3A低压差稳压器线性稳压器IC 调节器电源电路输出元件
文件：	总7页 (文件大小：190K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

SPX1587

3A Low Dropout Voltage Regulator

Adjustable & Fixed Output,

Fast Response

FEATURES

APPLICATIONS

• Adjustable Output Down To 1.2V

• Fixed Output Voltages 1.5, 2.5, 3.3, 5.0V

• Output Current Of 3A

• Powering VGA & Sound Card

• Power PC Supplies

• SMPS Post-Regulator

• Low Dropout Voltage 1.1V Typ.

• Extremely Tight Load And Line Regulation

• Current & Thermal Limiting

• High Efficiency “Green” Computer Systems

• High Efficiency Linear Power Supplies

• Portable Instrumentation

• Standard 3-Terminal Low Cost TO-220, TO-263 & TO-252

• Similar To Industry Standard LT1085/LT1585

• Constant Current Regulators

• Adjustable Power Supplies

• Battery charger

PRODUCT DESCRIPTION

The SPX1587 is a low power 3A adjustable and fixed voltage regulator that is very easy to use. It requires only 2 external resistors to

set the output voltage for adjustable version. The SPX1587 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 SPX1587 features low dropout of a maximum 1.2 volts.

The SPX1587 offers over current limit and full protection against reversed input polarity, reversed load insertion, and positive and

negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The I_Qof this device flows into the load, which

increases efficiency.

The SPX1587 are offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For a 5A low

dropout regulator refer to the SPX1585 data sheet.

PIN CONNECTIONS

TO-263-3 (T)

TO-220-3 (U)

TO-252 (R)

SPX1587

ADJ/GND V_OUTV_IN

V_IN

Front View

ADJ/GND

V_OUT

Top View

V_IN

ADJ/GND

OUT

Front View

Rev. 10/30/00

SPX1587

ABSOLUTE MAXIMUM RATINGS

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

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

Operating Junction Temperature Range ......................

SPX1587 Control Section.......................... -45°C +125°C

SPX1587 Power Transistor.........................-45°C +150°C

Maximum Input Voltage ...................................... 10V

Input to Output Voltage Differential Max........... 8.8V

ELECTRICAL CHARACTERISTICS ^{(NOTE 1) at I}_OUT= 10mA, T =25 C, unless otherwise specified.

SPX1587A

SPX1587

PARAMETER

CONDITIONS

Typ

Units

Min

Max

Min

Max

1.5V Version

Output Voltage (Note 2)

1.5

1.485

1.470

1.515

1.530

1.470

1.455

1.530

1.545

SPX1587-1.5V, 0 ≤I_OUT≤3A, 2.75V≤V_IN≤10V

2.5V Version

Output Voltage (Note 2)

2.5

2.475

2.450

2.525

2.550

2.450

2.425

2.550

2.575

SPX1587-2.5V, 0 ≤I_OUT≤3A, 4.0V≤V_IN≤10V

3.3V Version

Output Voltage (Note 2)

3.3

3.270

3.240

3.330

3.360

3.230

3.201

3.370

3.399

SPX1587-3.3V, 0 ≤I_OUT≤3A, 4.75V≤V_IN≤10V

SPX1587-5.0V, 0 ≤I_OUT≤3A, 6.5V≤V_IN≤10V

V_IN≤ 7V, P≤ P_MAX

5.0V Version

Output Voltage (Note 2)

5.0

4.95

4.90

5.05

5.10

4.900

4.850

5.100

5.150

All Voltage Options

Reference Voltage (V_REF

)

1.238

1.225

1.263

1.270

1.225

1.212

1.270

1.288

1.250

1.5V≤ (V_{IN -}V_OUT)≤(V_IN-V_OUT

10mA≤I_OUT≤3A

)

MAX

Min. Load Current (Note 3)

Line Regulation (∆V_REF(V_IN)) 2.75V≤V_IN≤7V, I_OUT=10mA, T_J=25°C

0.2

1.5V≤ (V_{IN -}V_OUT)≤ (V_IN-V_OUT

)

MAX

0.005

(Note 3)

0.005

0.05

1.1

0.2

0.3

1.2

0.2

0.3

1.2

_IN≤7V, I_OUT=0mA, T_J=25°C

(Note 2)

Load Regulation (∆V_REF

10mA≤I_OUT≤3A, (V_IN-V_OUT)=3V, T_J=25°C

(I_OUT))

(Note 3)

0≤I_OUT≤3A, V_IN=7V, T_J=25°C

(Note 2)

Dropout Voltage

Current Limit

∆V_REF=1%

I_OUT=3A

_OUT≤3A

V_IN=7V

1.4V≤ (V_IN- V_OUT) (Note3)

T_A=125°C, 1000 Hrs.

I_OUT

(

)

4.0

0.3

3.2

MAX

Long Term Stability

(Note 2)

0.01

Thermal Regulation

(∆V_OUT(Pwr))

0.020

%/W

T_A=25°C, 20 ms pulse

Temperature Stability

(∆V_OUT(T))

0.25

Output Noise, RMS

Thermal Resistance

0.003

°C/W

10Hz to 10kHz T_A= 25°c

TO-220

Junction to Tab

3.0

Junction to Ambient

Junction to Tab

DD Package

3.0

Junction to Ambient

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. 10/30/00

SPX1587

APPLICATION HINTS

Reducing parasitic resistance and inductance

The SPX1587 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 improve the stability

and the performances.

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.

Thermal Consideration

Stability

Although the SPX1587 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.

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’.

Ripple Rejection

Ripple rejection can be improved by adding a capacitor

between the ADJ pin and ground as shown in figure 6. 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 10µF for an electrolytic aluminum capacitor

or 4.7µF for a solid tantalum capacitor.

Assuming:

_IN= 10V, V_OUT= 5V, I_OUT= 1.5A, T_A= 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

P_D= (V_IN– V_OUT) * I_OUT= 7.5W

Junction Temperature

T_J= T_A+ P_D* (θ _{Case - HS}+ θ _HS+ θ _JC

However the value of the ADJ-bypass capacitor should be

chosen with respect to the following equation:

)

C = 1 / (6.28 * F_R* R₁)

For the Control Sections

T_J= 50 + 7.5*(0.5 +6=3) = 121.25°C

Where C

= value of the capacitor in Farads (select an

121.25°C < T_{J (max)}for the Control & Power Sections.

equal or larger standard value),

F_R= ripple frequency in Hz,

R₁= value of resistor R₁in Ohms.

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 ADJ-

bypass capacitor is not used, the output ripple will be

proportional to the ratio of the output voltage to the reference

voltage:

M = V_OUT/ V_REF

Where M = multiplier for the ripple seen when the ADJ pin

is optimally bypassed.

_REF= Reference Voltage

Rev. 10/30/00

SPX1587

Basic Adjustable Regulator

V_IN

V_OUT

3.3V

V_IN

V_OUT

SPX1587

10uF

R₁

R₂

V_REF

10uF

I_ADJ

50µA

Basic Fixed Regulator

V_OUT= V_REF* ( 1 + R/R₁) + I_ADJ* R₂

Fig.2 Basic Adjustable Regulator

Output Voltage

The fixed voltage LDO voltage regulators are simple to use

regulators since the V_OUTis 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.

Consider Figure 2. The resistance R₁generates a constant

current flow, normally the specified load current of 10mA.

This current will go through the resistance R₂to set the overall

output voltage. The current I_ADJis very small and constant.

Therefore its contribution to the overall output voltage is very

small and can generally be ignored.

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 R₁resistance from the resistor divider to the case,

and not to the load. For the same reason, it is best to connect

the resistor R₂to the Negative side of the load.

Parasitic Line

R^Pesistance

V_IN

SPX1587

Connect R to

Case of Regulator

R₁

R_L

R₂

Connect Rto Load

Fig.3 Basic Adjustable Regulator

Rev. 10/30/00

SPX1587

TYPICAL APPLICATIONS

V_IN

V_OUT

V_IN

OUT

SPX1587

OUT

SPX1587

C₂

C₁

R₁

R₂

ADJ

R₁

ADJ

V_OUT= V_REF(1 + R ) + I_ADJR₂

R²₁

LOAD

Fig. 5 Typical Adjustable Regulator

Fig. 4 3A Current output Regulator

(Note A)

V_IN

(Note A)

SPX1587 ^OUT

ADJ

OUT

V_OUT

SPX1587

10µF

121Ω

ADJ

R₁

121Ω

10µF

100µF

TTL

Input

150µF

2N3904

X_C

*C₁improves ripple rejection.

should be ~ R ₁at ripple frequency.

365Ω

R₂

365Ω

C₁

10µF*

Note A: V_IN(MIN)= (Intended V_OUT) + (V_{DROPOUT (MAX)}

)

Note A: V_IN(MIN)= (Intended V_OUT) + (V_{DROPOUT (MAX)}

)

Fig. 6 Improving Ripple Rejection

Fig.7 5V Regulator with Shutdown

Rev. 10/30/00

SPX1587

TYPICAL CHARACTERISTICS

Rev. 10/30/00

SPX1587

ORDERING INFORMATION

Ordering No.

SPX1587T

Precision

Output Voltage

Adj

Packages

3 Lead TO-263

3 Lead TO-220

3 Lead TO-252

1.5V

2.5V

3.3V

5.0V

Adj

SPX1587T-1.5

SPX1587T-2.5

SPX1587T-3.3

SPX1587T-5.0

SPX1587AT

1.5V

2.5V

3.3V

5.0V

Adj

SPX1587AT-1.5

SPX1587AT-2.5

SPX1587AT-3.3

SPX1587AT-5.0

SPX1587U

1.5V

2.5V

3.3V

5.0V

Adj

SPX1587U-1.5

SPX1587U-2.5

SPX1587U-3.3

SPX1587U-5.0

SPX1587AU

1.5V

2.5V

3.3V

5.0V

Adj

SPX1587AU-1.5

SPX1587AU-2.5

SPX1587AU-3.3

SPX1587AU-5.0

SPX1587R

1.5V

2.5V

3.3V

5.0V

Adj

SPX1587R-1.5

SPX1587R-2.5

SPX1587R-3.3

SPX1587R-5.0

SPX1587AR

1.5V

2.5V

3.3V

5.0V

SPX1587AR-1.5

SPX1587AR-2.5

SPX1587AR-3.3

SPX1587AR-5.0

Corporation

SIGNAL PROCESSING EXCELLENCE

Sipex Corporation

Headquarters and Main Offices:

22 Linnell Circle

Billerica, MA 01821

TEL: (978) 667-8700

FAX: (978) 670-9001

e-mail: sales@sipex.com

233 South Hillview Drive

Milpitas, CA 95035

TEL: (408) 935-7600

FAX: (408) 934-7500

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

hereing; neither does it convey any license under its patent rights nor the rights of others.

Rev. 10/30/00

SPX1587R-1.8 [SIPEX]

相关型号：

SPX1587R-1.8-L

SPX1587R-1.8-L/TR

SPX1587R-1.8/TR

SPX1587R-2.5

SPX1587R-2.5/TR

SPX1587R-3.3

SPX1587R-3.3-L

SPX1587R-3.3-L/TR

SPX1587R-3.3/TR

SPX1587R-5.0

SPX1587R-5.0-L

SPX1587R-5.0/TR