AS2701T [SIPEX]

Adjustable Positive LDO Regulator, 1.235V Min, 30V Max, 0.5V Dropout, PSSO5, TO-263, 5 PIN;


型号：	AS2701T
厂家：	SIPEX CORPORATION
描述：	Adjustable Positive LDO Regulator, 1.235V Min, 30V Max, 0.5V Dropout, PSSO5, TO-263, 5 PIN 光电二极管接口集成电路
文件：	总9页 (文件大小：143K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

AS2700/01/02

700mA Low Dropout Voltage Regulators

With Shutdown

(PRELIMINARY INFORMATION)

FEATURES

APPLICATIONS

• Output Current 700mA at 3.3V and 5V

• Internal Short Circuit Current Limit

• Dropout Voltage 0.5V at 700mA Output

• Extremely Tight Load and Line Regulation

• Very Low Temperature Coefficient

• Mirror Image Insertion Protection

• Unregulated DC Input Can Withstand -20V Reverse Battery

and +60V Positive Transients

• Battery Powered Systems

• Cordless Telephones

• Automotive Electronics

• Portable/ Palm Top / Notebook Computers

• Portable Consumer Equipment

• Portable Instrumentation

• SMPS Post-Regulator

• Voltage Reference

• Direct Replacement For LM2937 Socket

PRODUCT DESCRIPTION

The AS2700/01/02 are a low power positive voltage regulators. The AS2700/01/02 offers 700mA output current with a dropout

voltage of only 0.5V and over temperature dropout is up to 1V. The quiescent current is 10mA at differential output of 5V and output

current of 700mA. A higher quiescent current can exist when the device is in dropout mode (V_IN-V_OUT≤ 3V).

The regulator will automatically shut down to protect both the internal circuits and the load. This device also features short circuit and

thermal overload protection.

The AS2700/01/02 is offered in 3 and 5 pin TO-220, TO-263 and 3-pin SOT-223 packages compatible with other 5V and 3.3V

regulators, TO-263 and 3-pin SOT-223. The device is offered in standard output voltages of 5V and 3.3V as well as in adjustable

output regulator.

ORDERING INFORMATION

TO-220

TO-263

SOT-223

3-PIN

AS2700YM3-X

OPER.

3 / 5-PIN

TEMP. RANGE

-40 °C to +125°C

AS2700/01/02YU-X AS2700/01/02YT-X

X= Output Voltage (X = 3.3V, 5.0V)

Y = A or Blank for adjustable).

PIN CONNECTIONS

TO-220-3 (U)

TO-263-5 (T)

AS2700/01/02

TO-263-3 (T)

AS2700

TO-220-5 (U)

AS2701/02

SOT-223 (M3)

AS2700

Five Lead Package Pin Functions:

AS2701

AS2702

Adjust

Shutdown

GND

AS2700

4 5

1) Error

2 3 4

2) Input

3) GND

V_IN

V_OUT

GND

Top View

4) Output

5) Shutdown

Input

V_IN

V_OUT

GND

Output

Top View

V_IN

V_OUT

GND

Front View

Rev. 10/11/00

AS2700/01/02

ABSOLUTE MAXIMUM RATINGS

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

Lead Temp. (Soldering, 10 Seconds) .............................. 260°C

Feedback Input Voltage...................................... -1.5V to +30V

Shutdown Input Voltage..................................... -0.3V to +30V

Error Comparator Output ................................... -0.3V to +30V

Input Supply Voltage

Continuous .........................+12V

Transient................-20V to +60V

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

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

ESD Rating

.....................................2KV Min

ELECTRICAL CHARACTERISTICS at V = V + 5V, I = 700mA, C = 10 F, unless otherwise specified. Limits in

Boldface type apply over the entire operating temperatu^INre range. All ^Oother specifications are T_A= 25°C.

Parameter

Conditions

Typ.

AS2700/01/02A

AS2700/01/02B

Max

Units

(Note 2)

Min Max Min

3.3V Version

Output Voltage

3.3

3.267

3.333

3.234

3.366

3.217

3.382

3.185

3.415

-40°C≤TJ≤+125°C

1mA≤ I_L≤500mA

5V Version

Output Voltage

5.0

4.950

4.880

5.050

5.120

4.900

4.870

5.100

5.130

-40°C≤TJ≤+125°C

1mA≤ I_L≤700mA

All Voltage Options

Output Voltage

0.03

0.04

100

150

ppm/°C

%max

Temperature Coefficient

Line Regulation (Note 3)

(Note1)

6V≤ V_IN≤30V (Note4)

0.1

0.40

0.20

0.30

100

150

400

500

150

180

0.20

0.80

0.30

0.50

100

150

400

500

150

180

Load Regulation (Note 3)

Dropout Voltage (Note 5)

I_L= 1 to 700

I_L= 0.1 to 1mA

I_L= 1mA

I_L= 700mA

I_L= 1mA

375

100

Ground Current

µA

4.5

2.5

I_L= 700mA

V_OUT= 0

Current Limit

700

800

0.2

700

800

0.2

Thermal Regulation

0.05

%/w

Output Noise, 10Hz to 100kHz

IL = 100mA

C_L= 2.2µF

C_L= 33µF

400

200

1.0

µV

0.60

Vrms

Adjustable Versions Only

Reference Voltage

Over Temperature

(Note 6)

1.235

1.210

1.200

1.185

1.260

1.270

1.285

1.200

1.980

1.185

1.270

1.272

1.285

Feedback Pin Bias Current

Reference Voltage Temperature

Coefficient

(Note 7)

ppm/°C

NA/°C

Feedback Pin Bias Current

0.1

Temperature Coefficient

Rev. 10/11/00

AS2700/01/02

ELECTRICAL CHARACTERISTICS at V = V + 5V, I = 700mA, C = 22 F, unless otherwise specified. Limits in

Boldface type apply over the entire operating temperatu^INre range. All ^Oother specifications are T_A= 25°C.

Parameter

Conditions

Typ.

AS2700/01/02A

AS2700/01/02B

Max

Units

Min Max Min

Error Comparator

Output Leakage Current

Output Low Voltage

Upper Threshold Voltage

Lower Threshold Voltage

Hysteresis

V_OH= 30V

0.01

150

1.00

2.00

250

400

1.00

2.00

250

400

µA

VIN = 4.5V

IOL = 400µA

(Note 8)

140

Shutdown Input

Input Logic Voltage

Low (Regulator ON)

High (Regulator OFF)

VS = 2.4V

0.7

2.0

Shutdown Pin Input Current

150

800

1000

µA

100

600

750

VS = 30V

450

Regulator Output Current In

Shutdown

µA

Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.

Note 2: Unless otherwise specified all limits are guaranteed for T_j= 25°C, V_IN= 6V, I_L= 100µA and C_L= 1µF. Additional conditions for the 8-pin versions are

feedback tied to 5V tap and output tied to output sense (V_OUT= 5V) and V_SHUTDOWN≤ 0.8V.

Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are

covered under the specification for thermal regulation.

Note 4: Line regulation for the AS2700/01/02 is tested at 150°C for I_L= 1 mA. For I_L= 100µA and T_J= 125°C, line regulation is guaranteed by design to 0.2%. See

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

Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV 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 6: V_REF≤V_OUT≤ (Vin - 1V), 2.3 ≤Vin≤30V, 100µA≤I_L≤ 250 mA, T_J≤ T_JMAX

Note 7: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at 6V input. To

express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V_OUT/V_REF= (R1 + R2)/R2. For example, at a programmed output

voltage of 5V, the Error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant as a percent of V_OUTas

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

Note 8: V_SHUTDOWN≥ 2V, V_IN≤ 30V, V_OUT=0, Feedback pin tied to 5V Tap.

Note 9: 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.

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.

UNREGULATED DC

5V @ 700mA

MAX

INPUT

FEEDBACK

OUTPUT

SENSE

5V TAP

Ω

180k ..

ERROR

AMPLIFIER

FROM

CMOS OR

TTL

330kΩ ..

SHUTDOWN

Ω

60k ..

F..

______

60 mV

ERROR

ERROR DETECTION

COMPARATOR

TO CMOS OR

TTL

1.23V

REFERENCE

GROUND

AS2700/01/02 Block Diagram

Rev. 10/11/00

AS2700/01/02

APPLICATION HINTS

EXTERNAL CAPACITORS

high around 5V input (input voltage at which Vout = 4.75 ). Since

the AS2700/01/02’s 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.

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 250µA, 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.

The stability of the AS2700/01/02 requires a 10µF 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 500 kHz are the most important

parameters in the value of the capacitor. The capacitor 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 22µF and 0.15µF 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 22µF or

greater must be used for the condition of 750mA load at 1.23V

output.

PROGRAMMING THE OUTPUT VOLTAGE OF AS2700/01/02

The AS2700/01/02 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:

The AS2700/01/02, 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

AS2700/01/02 version with external resistors, a minimum load of

5mA 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.

_OUT= V_REF× (1 + R₁\ R₂)+ I_FBR₁

The V_REFis 1.235 and I_FBis the feedback bias current, nominally -20

nA. 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 I_FB

produces an error of typically 2% in V_OUT, which may be eliminated

at room temperature by trimming R₁. To improve the accuracy

choose the value of R₂= 100k this reduces the error by 0.17% and

increases the resistor program current by 12µA. Since the

AS2700/01/02 typically draws 100µA at no load with SHUTDOWN

open-circuited this is a small price to pay

ERROR DETECTION COMPARATOR OUTPUT

4.75V

REDUCING OUTPUT NOISE

OUTPUT

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 AS2700/01/02 but is relatively inefficient, as

increasing the capacitor from 1µF to 220µF only decreases the noise

from 430µV to 160µV_RMSfor a 100 kHz bandwidth at 5V output.

Noise could also be reduced fourfold by a bypass capacitor across R₁,

since it reduces the high frequency gain from 4 to unity. Pick

VOLTAGE

_______

ERROR*

_BYPASS≅ 1 / 2πR₁× 200 Hz

5.0V

INPUT

VOLTAGE

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_RMSfor a 100 kHz bandwidth at

5V output. With the bypass capacitor added, noise no longer scales

with output voltage so that improvements are more dramatic at higher

1.3V

* See Application Info.

_______

Figure 1. ERROR Output Timing

output voltages.

SHUTDOWN

The Comparator produces a logic low output whenever the

AS2700/01/02 output falls out of regulation by more than around

5%. This is around 75mV 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 AS2700/01/02 input is ramped up and down. The

ERROR signal becomes low at around 1.3V input, and goes

V_OUT

AS2702

GND

ADJ

Fig.2 Adjustable Voltage Regulator

Rev. 10/11/00

AS2700/01/02

TO-263-5L (T)

0.055 (1.397)

0.005 (4.470 0.127)

0.176

0.050

0.405 ± 0.005

0.127)

0.002

(1.270 0.051)

(10.287 ±

0.356

(9.042

0.005

0.127)

0.600 0.025

0.100

0.010

(15.24

0.635)

(2.540 0.254)

0.015

0.003

(0.381

0.074)

0.067

0.005

0.032 0.003

(1.702 0.127)

(0.813

0.076)

0° 8°

Rev. 10/11/00

AS2700/01/02

TO-263-3L (T)

(4.470 ^±

0.127)

0.051)

0.176^±

0.005

0.055 (1.397)

0.405 ^±

0.005

0.050^±0.002 (1.270 ^±

(10.287 0.127)

0.356 ^±0.005

(9.042 0.127)

0.600 ⁺_-0.025

(15.24

0.635)

0.100 0.010

(2.540^±

0.254)

0.003

0.015

0.103 BSC

(2.616)

0.050 (1.270)

(0.381 ⁺0.074)

0.032 ⁺_-0.001

(0.813 ⁺_-0.025)

0°

8°

Rev. 10/11/00

AS2700/01/02

TO-220-3L (U)

0.180 ± 0.005

(4.572 ± 0.127)

0.151D ± 0.002

(3.835 D ± 0.051)

0.408 ± 0.013

(10.36 ± 0.33)

0.050 ± 0.002

(1.270 ± 0.051)

0.110 ± 0.010

(2.794 ± 0.254)

0.250 ± 0.010

(6.350 ± 0.254)

Tapered 1^o

2 Sides

0.340 ± 0.010

(8.636 ± 0.254)

SEATING PLANE

1.020 ± 0.015

(25.910 ± 0.381)

0.150 MIN

(3.81 MIN)

7^oTyp.

0.540 ± 0.015

(13.720 ± 0.381)

0.410

(10.41)

0.050 TYP

(1.27 TYP)

0.200 ± 0.010

(5.080 ± 0.254)

0.015 ± 0.010/-0.015

(2.667± 0.254/-0.381)

0.100 ± 0.010

(2.540 ± 0.254)

0.015 ± 0.010/-0.002

(0.381± 0.254/-0.051)

0.032 ± 0.005

(0.813 ± 0.127)

Rev. 10/11/00

AS2700/01/02

TO-220-5L (U)

0.150 D 0.005

0.175

(4.45

0.005

0.13)

(3.81D

0.13)

0.400

(10.16

0.005

0.13)

0.050

(1.27

0.005

0.13)

0.108

(2.74

0.005

2.74)

0.250

(6.35

0.005

0.13)

0.590

(14.99

0.005

0.13)

SEATING

PLANE

1.137 REF

(28.88 REF)

7°

Typ.

0.547

(13.89

0.005

0.005)

0.067

(1.70

0.005

0.105

(2.67

0.005

0.13)

0.032

(0.81

0.005

0.13)

0.127)

0.268 REF

(6.81 REF)

0.268 REF

0.015

(0.38

0.005

0.13)

Rev. 10/11/00

AS2700/01/02

SOT-223-3L (M3)

0.124

0.116

0.146 0.295

0.130 0.264

0.041

0.033

0.0905 NOM

0.181 NOM

0.146

0.130

16 C

10 C

0.264

0.248

0.0040

0.0008

0.014

0.010

16 C

10 C Max

0.033

0.025

Rev. 10/11/00

AS2701T [SIPEX]

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