Datasheet SPX1085AR, SPX1085AR-1.5, SPX1085AR-2.5, SPX1085AR-3.3, SPX1085AR-5.0 Datasheet (Sipex Corporation)

3A Low Dropout Voltage Regulator

Adjustable & Fixed Output,

SPX1085

Fast Response

FEATURES

Adjustable Output Down To 1.2V

•

Fixed Output Voltages 1.5, 2.5, 3.3, 5.0V

•

Output Current Of 3A

•

Low Dropout Voltage 1.1V Typ.

•

Extremely Tight Load And Line Regulation

•

Current & Thermal Limiting

•

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

•

Similar To Industry Standard LT1085/LT1585

•

PRODUCT DESCRIPTION

The SPX1085 are low power 3A adjustable and fixed voltage regulators that are very easy to use. It requires only 2 external resistors to set the output voltage for adjustable version. The SPX1085 is designed for low voltage applications that offer 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 SPX1085 features low dropout of a maximum of 1.5 volts.

The SPX1085 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The I increases efficiency.

The SPX1085 are offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For a 8A low dropout regulator refer to the SPX1085 data sheet.

APPLICATIONS

Powering VGA & Sound Card

•

Power PC Supplies

•

SMPS Post-Regulator

•

High Efficiency “Green” Computer Systems

•

High Efficiency Linear Power Supplies

•

Portable Instrumentation

•

Constant Current Regulators

•

Adjustable Power Supplies

•

Battery charger

•

of this device flows into load which

Q

TO-263-3 (T)

ADJ/GND

SPX1085

1

2

V

OUT

Top View

PIN CONNECTIONS

TO-220-3 (U)

ADJ/GND

Front View

SPX1085

1

23

V

OUT

V

IN

3

V

IN

TO-252 (R)

SPX1085

2

1

ADJ/GND V

Front View

3

INVOUT

Rev. 10/30/00

SPX1085

ABSOLUTE MAXIMUM RATINGS

Lead Temp. (Soldering, 10 Seconds) .............................. 300°C Input Voltage........................................................ 30V

Storage Temperature Range ............................ -65° to +150°C Input to Output Voltage Differential Max ............ 30V

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

SPX1085 Control Section.......................... -45°C +125°C

SPX1085 Power Transistor.........................-45°C +150°C

ELECTRICAL CHARACTERISTICS

PARAMETER

1.5V Version

Output Voltage (Note 2)

2.5V Version

Output Voltage (Note 2)

3.3V Version

Output Voltage (Note 2)

5.0V Version

Output Voltage (Note 2)

Adjustable Version

Reference Voltage (V

All Voltage Options

Min. Load Current

Line Regulation (∆V

Load Regulation(∆V

Dropout Voltage

Current Limit I

Long Term Stability

Thermal Regulation (∆V Temperature Stability (∆V Output Noise, RMS

Thermal Resistance

OUT(MAX

OUT

)

(Pwr))

(T))

REF

(Note 3)

REF(VIN

REF(IOUT

SPX1085-1.5V, 0 ≤I

SPX1085-2.5V,0 ≤I

SPX1085-3.3V, 0 ≤I

SPX1085-5.0V, 0 ≤I

V

7V, P≤ P

)

))

≤

IN

1.5V≤ (V 10mA≤I

1.5V≤ (V

2.75V≤V

V

10mA≤I

))

3)

0≤I

∆

I VIN=7V

1.4V≤ (V

TA=125°C, 1000 Hrs.

TA=25°C, 20 ms pulse

0.25 %

10Hz to 10kHz TA=25°C

TO-220 Junction to Tab

DD Package Junction to Tab

IN -VOUT

≤

OUT

IN -VOUT

≤

IN

29V, I

≤

IN

V

OUT

3A, V

≤

OUT

=1% I

REF

IN- VOUT

3A

29V, I

≤

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

(NOTE 1) at I

CONDITIONS Typ

= 10mA, TA=25°C, unless otherwise specified.

OUT

SPX1085A

Min Max

3A, 2.75V≤V

≤

OUT

3A, 3.5V≤V

≤

OUT

3A, 4.75V≤V

≤

OUT

3A, 5.5V≤V

≤

OUT

MAX

)≤(VIN-V

)≤ (VIN-V

=10mA, TJ=25°C (Note 3)

OUT

=0mA, TJ=25°C (Note 2)

3A, (V

IN-VOUT

=7V, TJ=25°C (Note 2)

IN

OUT

) (Note3)

,

OUT)MAX

)=3V, TJ=25°C (Note

=3A (Note 3)

(Note 2)

3A

≤

Junction to Ambient

29V

≤

IN

29V

≤

IN

29V

≤

IN

29V

≤

IN

1.5

2.5

3.3

5.0

1.250 1.238 1.263

5 10 10

0.005 0.2 0.2 %

0.05 0.3 0.3 %

1.1

4.0

0.3

(Note 2)

0.01 0.020 0.020 %/W

0.003 % V

3.0 60

1.485

1.470

2.475

2.450

3.270

3.240

4.95

4.90

3.2

1 1 %

3.0

1.515

1.530

2.525

2.550

3.330

3.360

5.05

5.10

1.5

60

3.0 60

SPX1085

Min Max

1.470

1.455

2.450

2.425

3.230

3.201

4.900

4.850

1.225

3.2

3.0

1.530

1.545

2.550

2.575

3.370

3.399

5.100

5.150

1.270

1.5

A

60

3.0 60

Rev. 10/30/00

Units

V

mA

V

O

C/W

°

C/W

°

SPX1085

APPLICATION HINTS

The SPX1085 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 insure the stability and the performances.

Stability

The output capacitor is part of the regulator’s frequency compensation system. Either a 220µF aluminum electrolytic capacitor or a 47µF 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. When ADJ pin bypassing is used, the value of the output capacitor required increases to its maximum (220µF for an aluminum electrolytic capacitor, or 47µF for a solid tantalum capacitor). If the ADJ pin is not bypass, the value of the output capacitor can be lowered to 100µF for an electrolytic aluminum capacitor or 15µF for a solid tantalum capacitor. However the value of the ADJ-bypass capacitor should be chosen with respect to the following equation: C = 1 / ( 6.28 * F

Where C = value of the capacitor in Farads (select an equal or larger standard value), F R

= ripple frequency in Hz,

R

= value of resistor R1 in Ohms.

1

If an ADJ-bypass capacitor is use, the amplitude of the output ripple will be independent of the output voltage. If an ADJbypass 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 Where M = multiplier for the ripple seen when the ADJ pin is optimally bypassed. V

REF

* R1 )

R

REF

= Reference Voltage

Reducing parasitic resistance and inductance

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

Although the SPX1085 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.

Assuming: V

= 10V, V

IN

θ

Heatsink

= 6°C/W, θ

OUT

= 5V, I

Case-Heatsink

= 1.5A, TA = 50°C

OUT

= 0.5°C/W, θ JC = 3°C/W

Power dissipation under this condition P

= (VIN – V

D

OUT

) * I

= 7.5W

OUT

Junction Temperature T

= TA + PD * (

J

θ

Case – HS

+ θ HS + θ JC)

For the Control Sections T

= 50 + 7.5*(0.5 +6=3) = 121.25°C

J

121.25°C < T

for the control section.

J(max)

In both case reliable operation is insured by adequate junction temperature.

Rev. 10/30/00

SPX1085

Basic Adjustable Regulator

V

IN

SPX1085

I

ADJ

50µA

V

REF

V

= V

OUT

* ( 1 + R2/R1) + I

REF

ADJ

* R

2

V

OUT

R

1

R

2

Fig.2 Basic Adjustable Regulator

Output Voltage

Consider Figure 2. The resistance R go through the resistance R

to set the overall output voltage. The current I

2

generates a constant current flow, normally the specified load current of 10mA. This current will

1

is very small and constant. Therefore its contribution to

ADJ

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 R

resistance from the resistor divider to the case, and not to the load. For the same reason, it is best to connect the resistor R2 to

1

the Negative side of the load.

R

Parasitic Line

P

V

IN

SPX1085

Resistance

Connect R1 to

Case of Regulator

R

1

R

2

L

Connect R2 to Load

Fig.3 Basic Adjustable Regulator

Rev. 10/30/00

SPX1085

TYPICAL APPLICATIONS

V

IN

C

1

SPX1085

ADJ

OUT

R

1

V

IN

C

1

IN

SPX1085

ADJ

OUT

R

1

LOAD

V

= V

OUT

(1 + R2 ) + I

REF

ADJ R2

R

1

R

2

Fig. 4 3A Current output Regulator

Fig. 5 Typical Adjustable Regulator

(Note A)

V

IN

*C1 improves ripple rejection. Xc

should be ~ R

Note A: V

IN(MIN)

+

10µF

at ripple frequency.

1

= (Intended V

SPX1085

IN OUT

ADJ

) + (V

OUT

DROPOUT (MAX)

365Ω

)

R

1%

5V

R

1

121Ω

1%

2

+

10µF*

V

OUT

150µF

C

1

V

IN

(Note A)

TTL

Input

Note A: V

+

10µF

IN(MIN)

SPX1085

IN OUT

1k

= (Intended V

ADJ

2N3904

OUT

) + (V

121Ω

1%

365Ω

1%

DROPOUT (MAX)

Fig. 6 Improving Ripple Rejection

Fig.7 5V Regulator with Shutdown

V

OUT

C

2

5V

+

100µF

)

Rev. 10/30/00

SPX1085

TYPICAL CHARACTERISTICS

Rev. 10/30/00

SPX1085

ORDERING INFORMATION

Ordering No. Precision Output Voltage Packages

SPX1085T SPX1085T-1.5 SPX1085T-2.5 SPX1085T-3.3 SPX1085T-5.0 SPX1085AT SPX1085AT-1.5 SPX1085AT-2.5 SPX1085AT-3.3 SPX1085AT-5.0 SPX1085U SPX1085U-1.5 SPX1085U-2.5 SPX1085U-3.3 SPX1085U-5.0 SPX1085AU SPX1085AU-1.5 SPX1085AU-2.5 SPX1085AU-3.3 SPX1085AU-5.0 SPX1085R SPX1085R-1.5 SPX1085R-2.5 SPX1085R-3.3 SPX1085R-5.0 SPX1085AR SPX1085AR-1.5 SPX1085AR-2.5 SPX1085AR-3.3 SPX1085AR-5.0

2% Adj 3 Lead TO-263 2% 1.5V 3 Lead TO-263 2% 2.5V 3 Lead TO-263 2% 3.0V 3 Lead TO-263 2% 5.0V 3 Lead TO-263 1% Adj 3 Lead TO-263 1% 1.5V 3 Lead TO-263 1% 2.5V 3 Lead TO-263 1% 3.0V 3 Lead TO-263 1% 5.0V 3 Lead TO-263 2% Adj 3 Lead TO-220 2% 1.5V 3 Lead TO-220 2% 2.5V 3 Lead TO-220 2% 3.0V 3 Lead TO-220 2% 5.0V 3 Lead TO-220 1% Adj 3 Lead TO-220 1% 1.5V 3 Lead TO-220 1% 2.5V 3 Lead TO-220 1% 3.0V 3 Lead TO-220 1% 5.0V 3 Lead TO-220 2% Adj 3 Lead TO-252 2% 1.5V 3 Lead TO-252 2% 2.5V 3 Lead TO-252 2% 3.0V 3 Lead TO-252 2% 5.0V 3 Lead TO-252 1% Adj 3 Lead TO-252 1% 1.5V 3 Lead TO-252 1% 2.5V 3 Lead TO-252 1% 3.0V 3 Lead TO-252 1% 5.0V 3 Lead TO-252

SIGNAL PROCESSING EXCELLENCE

Corporation

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 und under it patent rights nor the rights of others.

Rev. 10/30/00

Datasheet SPX1085AR, SPX1085AR-1.5, SPX1085AR-2.5, SPX1085AR-3.3, SPX1085AR-5.0 Datasheet (Sipex Corporation)

Specifications and Main Features

Frequently Asked Questions

User Manual