Datasheet SPX2975ACN-3.0, SPX2975ACN-3.3, SPX2975ACN-5.0, SPX2975ACP-3.0, SPX2975ACP-3.3 Datasheet (Sipex Corporation)

FEATURES

3.0V, 3.3V and 5.0V Fixed Output Voltages

•

Very Low Quiescent Current

•

Low Dropout Voltage

•

Extremely Tight Load And Line Regulation

•

Very Low Temperature Coefficient

•

Needs Only 1µF For Stability

•

Current & Thermal Limiting

•

Unregulated DC Input Can Withstand -20V Reverse Battery

•

And +60V Positive Transients

Similar Replacement For LP2950/LP2951 Sockets

•

SPX2975 SO-8 versions only

Error Flag Warns Of Output Dropout

•

Logic- Controlled Electronic Shutdown

•

Output Programmable from 1.24 to 29V

•

SPX2975

180 mA Low Dropout Voltage Regulators

APPLICATIONS

Battery Powered Systems

•

Cordless Telephones

•

Radio Control Systems

•

Portable/Palm Top/Notebook Computers

•

Portable Consumer Equipment

•

Portable Instrumentation

•

Avionics

•

Automotive Electronics

•

SMPS Post-Regulator

•

Voltage Reference

•

PRODUCT DESCRIPTION

The SPX2975 is a low power voltage regulator. This device is an excellent choice for use in battery-powered applications such as cordless telephones, radio control systems, and portable computers. The SPX2975 features very low quiescent current and very low dropout voltage (Typ. 50mV at light load and 380 mV at 180 mA). This includes a tight initial tolerance of 0.5% typ., extremely good load and line regulation 0.05% typ. and very low output temperature coefficient, making the SPX2975 useful as a low-power voltage reference. Other additional key features include higher output current (150mA), positive transient protection up to 60V (Load dump), and the ability to survive an unregulated input voltage transient of -20V below ground (reverse battery).

The error flag output feature is used as power-on reset for warning of a low output voltage, due to falling voltage input of batteries. Another feature is the logic-compatible shutdown input which enables the regulator to be switched on and off. The SPX2975 is offered in a 3-pin TO-92 package compatible with other 5V regulators. The SPX2975 is available in 8-pin plastic, SO-8 packages.

PIN CONNECTIONS

V

OUT

SENSE

SHUTDOWN

GND

8-Pin Surface Mount (S)

1

2

SPX2975

3

4

8

7

6

5

V

FEEDBACK

5V TAP

ERROR

IN

TO-92 (N)

2

13

V

IN

GND

V

OUT

Top View

Bottom View

Rev. 10/30/00

SPX2975

ABSOLUTE MAXIMUM RATINGS

Power Dissipation..........................................Internally Limited Input Supply Voltage (Survival) ......................-20V to +60V

Lead Temp. (Soldering, 5 Seconds) ................................ 260°C Feedback Input Voltage ..................................-1.5V to +30V

Storage Temperature Range ............................-65° to +150°C Shutdown Input Voltage..................................-0.3V to +30V

Operating Junction Temperature Range (Note 10) Error Comparator Output................................-0.3V to +30V

SPX2975................................................... -55° to +150°C ESD Rating .............................................................2KV Min

SPX2975AC/SPX2975C .......................... -40° to +125°C

ELECTRICAL CHARACTERISTICS

temperature range.

PARAMETER CONDITIONS

Output Voltage

T

J

-25°C ≤T

-40°C ≤T

Output Voltage

Output Voltage T

100 µA ≤I T

J

-25°C ≤T

-40°C ≤T

Output Voltage

100 µA ≤I

T Output Voltage Temperature Coefficient Line Regulation (Note 3)

Load Regulation (Note 3)

Dropout Voltage (Note 5)

Ground Current

(Note 1)

6V ≤V

100 µA ≤I

I

L

I

L

I

L

I

L

I

L

I

L

Current Limit V

Thermal Regulation 0.05 0.2 0.05 0.2 %/W

Output Noise, 10Hz to 100kHz

C

(Bypass = 0.01 µF

pins 7 to 1(SPX2975))

8-Pin Versions Only

Reference Voltage 1.22 1.235 1.25 1.21 1.23 1.26 V

Reference Voltage Over Temperature

( Note 6) Feedback Pin Bias Current 40 60 40 60 nA

Reference Voltage Temperature

(Note 7) 20 50 ppm/°C Coefficient Feedback Pin Bias Current

0.1 0.1 nA/°C Temperature Coefficient Output Leakage Current V

Output Low Voltage VIN = 4.5V

I

OL

Upper Threshold Voltage (Note 8) 40 60 40 60 mV

Lower Threshold Voltage (Note 8) 75 95 75 95 mV

Hysteresis (Note 8) 15 15 mV

(Note 2)

= 25°C

≤85°C

J

+125°C

≤

J

≤180 mA

L

T

≤

JMAX

= 25°C

≤85°C

J

+125°C

≤

J

≤180 mA

L

T

≤

≤30V (Note 4)

IN

180 mA

≤

L

= 100µ A = 100 mA = 180 mA

= 100 µA = 100 mA = 180 mA

= 0 130 200 130 200 mA

OUT

= 1µF

L

= 200 µF

L

= 13.3 µF

L

= 30V 0.01 1 0.01 1

OH

= 400µA

at VS=15V, TA=25°C, unless otherwise specified.

Boldface apply

SPX2975AC

Min Typ Max

3.2835

3.267

3.2608

3.3 3.3165

3.333

3.3396

3.2505 3.3 3.3495 3.201 3.3 3.399 V

4.975

4.95

4.94

5.0

5.025

5.050

5.06

4.925 5.0 5.075 4.85 5.0 5.15 V

20 50 ppm/°C

0.03 0.1 0.04 0.2 %

0.04 0.1 0.1 0.2 %

50

380 450

150

8

18

430

80 450 500

170

150 12 22

430 160 100

SPX2975AC

1.19 1.27 1.18 1.28 V

150 250 150 250 mV

SPX2975C

Min Typ Max

3.267

3.3 3.333

3.2505

3.2604

4.95

4.925

4.90

5.0

50

380 450

8

18

160 100

SPX2975C

over the full operating

3.695

3.3396

5.05

5.075

5.10

80 450 500

170

12

22

UNITS

V

mV

A

µ

mA mA

V rms

µ

A

µ

Rev. 10/30/00

SPX2975

PARAMETER CONDITIONS

(Note 2)

Input Logic Voltage Low (Regulator ON)

High (Regulator OFF)

Shut Down Pin Input Current VS = 2.4V

= 30V

V

Regulator Output Current in

S

(Note 9) 3 10 3 10

Shutdown

Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.

Note 1:

Unless otherwise specified all limits guaranteed for T

Note 2:

feedback tied to 5V tap and output tied to output sense (V

Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are

Note 3:

= 25°C, VIN = 6V, IL = 100µA and CL = 1 µF. Additional conditions for the 8-pin versions are

J

= 5V) and V

OUT

covered under the specification for thermal regulation.

: Line regulation for the SPX2975 is tested at 150°C for I

Note 4

= 1mA. For IL = 100µA and TJ = 125°C, line regulation is guaranteed by design to 0.2%. See

L

typical performance characteristics for line regulation versus temperature and load current.

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

Note 5:

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

V

Note 6: Note 7:

REF

Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at 6V input. To

≤ (VIN - 1V), 2.3 ≤V

V

≤

OUT

30V, 100µA≤I

≤

IN

100 mA, T

≤

L

express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V voltage of 5V, the error output is guaranteed to go low when the output drops by 95mV x 5V/1.235 = 384mV. Thresholds remain constant as a percent of V V

is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed.

OUT

V

Note 8: Note 9: Note 10:

SHUTDOWN

All typical values are not guaranteed. The value could vary from lot to lot.

The junction -to-ambient thermal resistance of the TO-92 package is 180°C/ W with 0.4” leads and 160°C/ W with 0.25” leads to a PC board.

≥ 2V, VIN ≤ 30V, V

=0, Feedback pin tied to 5V Tap.

OUT

The thermal resistance of the 8-Pin DIP package is 105°C/W junction-to-ambient when soldered directly to a PC board. Junction-to-ambient thermal resistance for the SOIC (S) package is 160°C/W.

BLOCK DIAGRAM

UNREGULATED DC

+

FEEDBACK

7

FROM CMOS OR TTL

3

SHUTDOW N

+

60 mV

1.23V

+

REFERENCE

SPX2975AC

Min Typ Max

1.3 0.7 2 1.3 0.7 V

2

30

675

SHUTDOWN

≤

J

≤ 0.8V.

.

T

JMAX

8

INPUT

+ _

ERROR AMPLIFIER

+

_

SPX2975 Block Diagram

ERROR DETECTION CO MPAR ATOR

50

800

OUT/VREF

Min Typ

SPX2975C

Max

30

675

50

800

= (R1 + R2)/R2. For example, at a programmed output

1

OUTPUT

ΩΩΩΩ

180k

ΩΩΩΩ

..

60k

..

2

SENSE

6

5V TAP

5

______

ERROR

4

GROUND

5V @ 180mA

MAX

+

µµµµ

.. 1 F

TO CMOS OR TTL

330k

UNITS

A

µ

A

µ

OUT

ΩΩΩΩ

..

as

Rev. 10/30/00

APPLICATION HINTS

EXTERNAL CAPACITORS

The stability of the SPX2975 requires a 1.0µF or greater capacitor between output and ground. Oscillation could occur without this capacitor. Most types of tantalum or aluminum electrolytic works fine here. For operations below -25°C solid tantalum is recommended since the many aluminum types have electrolytes that freeze at about -30°C. The ESR of about 5Ω or less and resonant frequency above 500kHz are the most important parameters in the value of the capacitor. The capacitors value may be increased without limit. At lower values of output current, less output capacitance is required for stability. For the currents below 10mA the value of the capacitor can be reduced to 0.33µF and 0.1µF for 1mA. More output capacitance is needed for the 8-pin version at voltages below 5V since it runs the error amplifier at lower gain. At worst case 3.3µF or greater must be used for the condition of 10mA load at 1.23V output. The SPX2975, unlike other low dropout regulators will remain stable and in regulation with no load in addition to the internal voltage divider. This feature is especially important in applications like CMOS RAM keep-alive. When setting the output voltage of the SPX2975, a minimum load of 1µA is recommended If there is more than 10 inches of wire between the input and the AC filter capacitor or if a battery is used as the input then a 1µA tantalum or aluminum electrolytic capacitor should be placed from the input to the ground. Instability can occur if there is stray capacitance to the SPX2975 feedback terminal (pin 7). This could cause more problems when using a higher value of external resistors to set the output voltage. This problem can be fixed by adding a 100 pF capacitor between output and feedback and increasing the output capacitor to at least 3.3µF.

ERROR DETECTION COMPARATOR OUTPUT

The Comparator produces a logic low output whenever the SPX2975 output falls out of regulation by more than around 5%. This is around 60mV offset divided by the 1.235 reference voltage. This trip level remains 5% below normal regardless of the programmed output voltage of the regulator. Figure 1 shows the timing diagram depicting the ERROR signal and the regulator output voltage as the SPX2975 input is ramped up and down. The ERROR signal becomes low at around 1.3V input, and goes high around 5V input (input voltage at which Vout = 4.75 ). Since the SPX2975 dropout voltage is load dependent, the input voltage trip point (around 5V) will vary with the load current. The output voltage trip point (approx. 4.75V) does not vary with load.

SPX2975

The error comparator has an open-collector output which requires an external pull-up resistor. Depending on the system requirements the resistor may be returned to 5V output or other supply voltage. In determining the value of this resistor, note that the output is rated to sink 400µA, this value adds to battery drain in a low battery condition. Suggested values range from 100K to 1MΩ. If the output is unused this resistor is not required.

PROGRAMMING THE OUTPUT VOLTAGE OF SPX2975

The SPX2975 may be pin-strapped for 5V using its internal voltage divider by tying Pin 1 (output) to Pin 2 (sense) and Pin 7 (feedback) to Pin 6 (5V Tap). Also, it may be programmed for any output voltage between its 1.235V reference and its 30V maximum rating . As seen in Figure 2, an external pair of resistors is required. Refer to the below equation for the programming of the output voltage:

V

= V

OUT

The V

is 1.235 and IFB is the feedback bias current, nominally

ref

-20nA. The minimum recommended load current of 1µA forces an upper limit of 1.2 MΩ on value of R2. If no load is presented the IFB produces an error of typically 2% in V room temperature by trimming R the value of R

= 100k this reduces the error by 0.17% and increases

2

the resistor program current by 12µA. Since the SPX2975 typically draws 60µA at no load with Pin 2 open-circuited this is a small price to pay

REDUCING OUTPUT NOISE

It may be an advantage to reduce the AC noise present at the output. One way is to reduce the regulator bandwidth by increasing the size of the output capacitor. This is the only way that noise can be reduced on the 3 lead SPX2975 but is relatively inefficient, as increasing the capacitor from 1µF to 220µF only decreases the noise from 430µV to 160µV rms for a 100kHz bandwidth at 5V output. Noise could also be reduced fourfold by a bypass capacitor across R since it reduces the high frequency gain from 4 to unity. Pick

or choose 0.01µF. When doing this, the output capacitor must be increased to 3.3µF to maintain stability. These changes reduce the output noise from 430µV to 100µV output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages.

× (1 + R1\ R2)+ IFBR

REF

. To improve the accuracy choose

1

C

BYPASS

1 / 2πR

≅

RMS

1

which may be eliminated at

OUT

× 200 Hz

1

for a 100kHz bandwidth at 5V

,

1

Rev. 10/30/00

TYPICAL PERFORMANCE CHARACTERISTICS

SPX2975

Rev. 10/30/00

TYPICAL PERFORMANCE CHARACTERISTICS

(continued)

SPX2975

Rev. 10/30/00

TYPICAL APPLICATIONS

4.75V

OUTPUT

VOLTAGE

_______

ERROR*

INPUT

VOLTAGE 1.3V

* See Application

Figure 1. ERROR Output Timing

+

5.0V

_______

+V

IN

470K

ΩΩΩΩ

470K

..

______

5

ERROR

ΩΩΩΩ

..

3

SD

+V

SPX2975

GND

4

8

IN

Latch Off When Error Flag Occurs

V

FB

OUT

7

+

ERROR

OUTPUT

SPX2975

+V

IN

100K

5

______ ERROR

8

+V

IN

V

OUT

1.2 to 30V

1

SPX2975

3

SHUTDOWN

INPUT

+

1

R

V

OUT

+

1

2

µµµµ

1

F

ERROR

OUTPUT

SHUTDOWN

INPUT

MINIMUM INP UT-OUTPUT VOLTAGE RANGES FROM 4mV to 400mV.

EPENDING ON LOAD CURRENT, CURRENT LIMIT IS TYPICALLY 160mA

SD

GND

FB

7

4

1.23V

V

Figure 2. Adjustable Regulator

+V

IN

8

+V

SPX2975

GND

4

IN

FB

7

3

5

______

ERROR

SD

R

REF

1

V

OUT

+

1

R

2

3.3uF

.01uF

*V

= V

OUT

IN

Wide Input Voltage Range Current Limiter

Rev. 10/30/00

TYPICAL APPLICATIONS

6V

+

SEALED

120K

LEADACID BA TTERY SOURCE

FB

FOR 5.5 V

400K

39k

ΩΩΩΩ

RESET

-

C4

+

39k

ΩΩΩΩ

_

5

ERROR

3

SD

+V

____

IN

6V LEADACID BATTERY

1%

100k

1k

ΩΩΩΩ

-

C1

+

-

C2

+

-

1%

1k

ΩΩΩΩ

C3

+

10k

R

ΩΩΩΩ

3

1%

20k

ΩΩΩΩ

Regulator with State-of-Charge indicator

(continued)

1.5K

ΩΩΩΩ

SPX385

ΩΩΩΩ

1N457

+V

8

IN

1

V

OUT

SPX2975

GND

4

SENSE

2

ΩΩΩΩ

100K

3

SD

Low Battery Disconnect

8

_

SPX2975

GND

4

* OPTIONAL LATCH OFF WHEN DROPOUT OCCURS. ADJUST R3 FOR C2 SWITCHING WHE N V

** OUTP UTS GO LOW WHEN VIN DROPS BELOW DESIGNATED THRESHOLDS

SENSE

TAP

100k

ΩΩΩΩ

100k

100κΩ

100κΩ100κΩ

IS 6.0V

IN

2

+V

1

V

OUT

7

FB

6

ΩΩΩΩ

= 5V

OUT

+

1

<5.8V**

<6.0V**

<6.2V**

F

µµµµ

SPX2975

MAIN V-

MEMORY V+

+

µµµµ

1

F

ΩΩΩΩ

20K

NI-CAD BACKUP BATTER Y

Rev. 10/30/00

TYPICAL APPLICATIONS

(continued)

3

AUX SHUTDOWN

ON

OFF

TEMP SENSOR

+

SPX35

4

20mA

8

+V

IN

1N4001

0.1uF

SPX2975

GND

4

Open Circuit Detector for 4mA to 20mA Current Loop

1

V

OUT

7

FB

1N457

MIN VOLTAGE = 4V

+V

IN

8

+V

SD

IN

_______

ERROR

5

SPX2975

1

V

OUT

GND

4

FB

7

8.2K

ΩΩΩΩ

System Over Temperature Protection Circuit

+5V

4.7mA

OUTPUT

2

Ω

..

360K

ΩΩΩΩ

10K

5 DEGREE SHUTDOWN FLAG

EXTERNAL CIRCUIT PROTECTED OVER TEMPERATURE (V+ GOES OF F TEMP > 125)

UNREGULATED INPUT

5

IN

3

V

TAP

SPX2975

FB

7

300 mA Regulator with 0.75 Dropout

GND

V

OUT

SENSE

4

OR

RELAY

330K

Ω

..

27K

Ω

..

+

4.7uF

1

2

5V

OUTPUT

LOAD 50mA TO 300 mA

2N5432

Rev. 10/30/00

SPX2975

ORDERING INFORMATION

Ordering No. Precision Output Voltage Packages

SPX2975N-3.0 SPX2975N-3.3 SPX2975N-5.0 SPX2975ACN-3.0 SPX2975ACN-3.3 SPX2975ACN-5.0 SPX2975CP-3.0 SPX2975CP-3.3 SPX2975CP-5.0 SPX2975ACP-3.0 SPX2975ACP-3.3 SPX2975ACP-5.0

1% 3.0V 3 Lead TO-92 1% 3.3V 3 Lead TO-92 1% 5.0V 3 Lead TO-92

0.5% 3.0V 3 Lead TO-92

0.5% 3.3V 3 Lead TO-92

0.5% 5.0V 3 Lead TO-92 1% 3.0V 8 Lead SOIC 1% 3.3V 8 Lead SOIC 1% 5.0V 8 Lead SOIC

0.5% 3.0V 8 Lead SOIC

0.5% 3.3V 8 Lead SOIC

0.5% 5.0V 8 Lead SOIC

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 under its patent rights nor the rights of others.

Rev. 10/30/00

Datasheet SPX2975ACN-3.0, SPX2975ACN-3.3, SPX2975ACN-5.0, SPX2975ACP-3.0, SPX2975ACP-3.3 Datasheet (Sipex Corporation)

Specifications and Main Features

Frequently Asked Questions

User Manual