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SPX1202

600mA Low Dropout Voltage Regulator

FEATURES

■

Guaranteed 600mA Output

■

Three Terminal Adjustable or Fixed

2.5V, 3V and 3.3V

■

Low Quiescent Current

■

Low Dropout Voltage of 1.1V at Full Load

■

0.2% Line and 0.3% Load Regulation

■

Voltage Temperature Stability 0.05%

■

Overcurrent and Thermal Protection

■

Available Packages: SOT-223,TO-252,

TO-220, and TO-263

APPLICATIONS

■

SCSI-II Active Terminator

■

Portable/ Palm Top / Notebook

Computers

■

Battery Chargers

■

Disk Drives

Available in Lead Free Packaging

■

Portable Consumer Equipment

■

Portable Instrumentation

■

SMPS Post-Regulator

Now Available in Lead Free Packaging

Refer to page 6 for pinouts.

DESCRIPTION

The SPX1202 is a low power positive-voltage regulator designed to satisfy moderate power

requirements with a cost effective, small footprint solution. This device is an excellent choice for

use in battery-powered applications and portable computers. The SPX1202 features very low

quiescent current and a low dropout voltage of 1.1V at a full load. As output current decreases,

quiescent current flows into the load, increasing efficiency. SPX1202 is available in adjustable

or fixed 2.5V, 3V and 3.3V output voltages.

The SPX1202 is offered in several 3-pin surface mount packages: SOT-223, TO-252, TO-220

and TO-263. An output capacitor of 10F provides unconditional stability while a smaller 2.2F

capacitor is sufficient for most applications.

BLOCK DIAGRAM

Current Limit

OUT

AMP

Thermal Limit

REF

ADJ/GND

ADJ

~50A

–

Mar3-07

SPX202 600 mA Low Dropout Linear Regulator

ABSOLUTE MAXIMUM RATINGS

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

Lead Temperature (soldering, 5 seconds) .................. 260C

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

Operating Junction Temperature Range ..... -40C to +125C

Input Supply Voltage ..................................................... +20V

ESD Rating .............................................................. 2kV min

ELECTRICAL CHARACTERISTICS

at V

OUT

+ 1.5V, T

= 25C, C

= C

OUT

= 10F, unless otherwise specified. Limits in

Boldface

applies over the

full operating temperature range.

PARAMETER

2.5V Version

Output Voltage

3.0V Version

Output Voltage

3.3V Version

Output Voltage

All Output Options

Reference Voltage

Output Voltage

Temperature Stability

Line Regulation

CONDITIONS

OUT

= 10mA, V

= 5.00V

≤I

OUT

≤600mA,

4.50V

≤V

≤10V

OUT

= 10mA, V

= 5.00V

≤I

OUT

≤600mA,

4.50V

≤V

≤10V

OUT

= 10mA, V

= 5.00V

≤I

OUT

≤600mA,

4.50V

≤V

≤10V

OUT

=10mA, (V

- V

OUT

) = 2V

10≤I

OUT

≤600mA,

1.4V

≤(V

-V

OUT

)≤10V

(Note 1)

4.50V≤V

≤12V,V

OUT

=3.00,I

OUT

4.80V≤V

≤12V,V

OUT

=3.30,I

OUT

6.50V≤V

≤12V,V

OUT

=5.00,I

OUT

0≤I

OUT

≤600mA,V

=4.50V,V

OUT

=3.00

0≤I

OUT

≤600mA,V

=4.80V,V

OUT

=3.30

0≤I

OUT

≤600mA,V

=6.50V,V

OUT

=5.0

=100mA

=600mA

4.25V≤V

≤6.5V

-V

OUT

)=5V

25C, 30mS Pulse

RIPPLE

=120Hz, (V

-V

OUT

)=3V,

RIPPLE

=1V

125C, 1000Hrs

% of V

OUT

, 10Hz≤f≤10kHz

Junction to Case, at tab

TYP

2.475

2.450

2.970

2.940

3.267

3.234

1.238

1.225

MIN

2.500

MAX

2.525

2.550

3.030

3.060

3.333

3.366

1.262

1.270

0.05

UNITS

3.000

3.300

1.250

1.00

1.05

5.00

.850

0.01

7.00

10.00

12.00

15.00

1.10

1.15

10.00

1.0

0.1

0.03

0.003

Load Regulation

Dropout Voltage

(Note 2)

Quiescent Current

Adjust Pin Current

Current Limit

Thermal Regulation

Ripple Rejection

Long Term Stability

RMS Output Noise

Thermal Resistance

A

%/W

C/W

NOTES:

Note 1: Output temperature coefficient is defined as the worst case voltage change divided by the total temperature range.

Note 2: Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV below its nominal value measured at 1V differential at

very low values of programmed output voltage, the minimum input supply voltage of 2V ( 2.3V over temperature) must be taken into account.

Note 3: Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied excluding load or line regulation effect.

Mar3-07

SPX202 600 mA Low Dropout Linear Regulator

TYPICAL PERFORMANCE CHARACTERISTICS

Line Regulation at 25C

3.320

3.315

3.310

3.305

3.300

3.295

3.290

3.285

3.280

100

Output Current (mA)

1000

3.330

Vout (V)

Output Voltage (V)

Series 1

Series 2

3.320

3.310

3.300

4.8

9.8

Vin (V)

14.8

Figure 1. Load Regulation for SPX1202M3-3.3;

=4.8V, C

OUT

=2.2F

Figure 2. Line Regulation for SPX1202M3-3.3;

=4.8V to 16V, C

OUT

=2.2F

Current Limit VS Temp

Dropout Voltage (V)

1.3

1.2

1.1

1.0

0.9

100

200

300

400

500

600

700

800

900 1000

Output Current (mA)

Current Limit (A)

2.00

1.50

1.00

0.50

0.00

-50

-25

Series 1

Series 2

100 125

Temp (C)

Figure 3. Dropout Voltage vs Output Current for

SPX1202M3-3.3; V

=4.89V, C

OUT

=2.2F

Figure 4. Current Limit for SP1202M3-3.3; V

=4.8V,

OUT

=1.0F, I

OUT

pulsed from 10mA to Current

Limit

3.340

SCOPE TRACING MISSING

OUT

(V)

2.320

3.300

3.280

3.260

3.240

-50

Series 1

Series 2

-30

-10

110 130

Temp (C)

Figure 5. Current Limit for SPX1202M3-3.3, Output

Voltage Deviation with I

OUT

=10mA to 1A Step.

Mar3-07

Figure 6. V

OUT

vs Temperature I

OUT

pilsed from 10mA to

Current Limit

SPX202 600 mA Low Dropout Linear Regulator

APPLICATION INFORMATION

Output Capacitor

To ensure the stability of the SPX1202, an

output capacitor of at least 10F (tantalum or

ceramic)or 50F (aluminum) is required. The

value may change based on the application

requirements of the output load or temperature

range. The value of ESR can vary based on the

type of capacitor used in the applications. The

recommended value for ESR is 0.5Ω or less. A

larger value of output capacitance (up to 100F)

can improve the load transient response.

SOLDERING METHODS

The SPX1202 SOT-223 package is designed to

be compatible with infrared reflow or vapor-

phase reflow soldering techniques. During sol-

dering, the non-active or mildly active fluxes

may be used. The SPX1202 die is attached to

the heatsink lead which exits opposite the input,

output, and ground pins.

Hand soldering and wave soldering should be

avoided since these methods can cause damage

to the device with excessive thermal gradients

on the package. The SOT-223 recommended

soldering method are as follows: vapor phase

reflow and infrared reflow with the component

preheated to within 65C of the soldering tem-

perature range

THERMAL CHARACTERISTICS

The thermal resistance of SPX1202 depends on

the type of package and PC board layout as

shown in Table 1. The SPX1202 features the

internal thermal limiting to protect the device

during overload conditions. Special care needs

to be taken during continuous load conditions

such that the maximum junction temperature

does not exceed 125C. Thermal protection is

activated at >144C and deactiviated at <137C.

Taking the FR-4 printed circuit board and 1/16

thick with 1 ounce copper foil as an experiment,

the PCB material is effective at transmitting

heat with the tab attached to the pad area and a

ground plane layer on the backside of the sub-

strate. Refer to table 1 for the results of the

experiment.

The thermal interaction from other components

Mar3-07

50 X 50mm

35 X 17mm

16 X 10mm

Figure 7. Substrate Layout for SOT-223

in the application can effect the thermal resis-

tance of the SPX1202. The actual thermal resis-

tance can be determined with experimentation.

SPX1202 power dissipation is calculated as

follows:

= (V

- V

OUT

)(I

OUT

)

Maximum Junction Temperature range:

= T

AMBIENT

(max) + P

* (Thermal Resistance)

(Junction-to-ambient)

Maximum junction temperature must not ex-

ceed the 125C.

Ripple Rejection

Ripple rejection can be improved by adding a

capacitor between the ADJ pin and ground as

shown in Figure 7. When ADJ pin bypassing is

used, the value of the output capacitor required

increases to its maximum. If the ADJ pin is not

bypassed, the value of the output capacitor can

be lowered to 10F for an electrolytic aluminum

capacitor or 2.2F for a solid tantalum capacitor

(Fig 10).

However the value of the ADJ-bypass capacitor

should be chosen with respect to the following

equation:

C = 1 / ( 6.28 * F

* R

)

Where C = value of the capacitor in Farads

(select an equal or larger standard value),

= ripple frequency in Hz,

= value of resistor R

in Ohms.

If an ADJ-bypass capacitor is used, the ampli-

SPX202 600 mA Low Dropout Linear Regulator

tude 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

=1.25V

Output Voltage

The output of the adjustable regulator can be set

to any voltage between 1.25V and 15V. The

value of V

OUT

can be quickly approximated

using the formula. (Figure 9)

OUT

=1.25 *(R

+ R

)/R

A small correction to this formula is required

depending on the values of resistors R1 and R2,

since adjustable pin current (approx 50A) flows

through R2. When I

ADJ

is taken into account, the

formula becomes

OUT

= V

REF

(1+ (R

)) + I

ADJ

* R

where V

REF

=1.25V.

PC BOARD

AREA mm

TOPSIDE COPPER

AREA mm

BACKSIDE COPPER

AREA mm

THERMAL RESISTANCE

JUNCTION TO AMBIENT

C/W

2500

1600

2500

1600

900

Table 1

2500

1250

950

2500

1800

600

1250

915

600

240

2500

1600

900

TYPICAL APPLICATIONS

4.7F +

SPX1202

ADJ

OUT

LOAD

4.7F + C

SPX1202

ADJ

50A

OUT

REF

OUT

REF

OUT

= V

REF

(1+R

) +I

ADJ

Figure 8. 600mA Current Source

Mar3-07

Figure 9. Typical Adjustable Regulator

SPX202 600 mA Low Dropout Linear Regulator