Advanced Monolithic Systems AMS2954 Service Manual

http://www.BDTIC.com/AMS

Advanced AMS2954

Monolithic 250mA LOW DROPOUT VOLTAGE REGULATOR
Systems

RoHS compliant

FEATURES APPLICATIONS

• 2.5V, 3.0V, 3.3V and 5.0V Versions • Battery Powered Systems

• High Accuracy Output Voltage • Portable Consumer Equipment

• Extremely Low Quiescent Current • Cordless Telephones

• Low Dropout Voltage • Portable (Notebook) C omputers

• Extremely Tight Load and Line Regulation • Portable Instrumentation

• Very Low Temperature Coefficient • Radio Control Systems

• Current and Thermal Limiting • Automotive Electronics

• Needs Minimum Capacitance (1µF) for Stability • Avionics

• Unregulated DC Positive Transients 60V • Low-Power Voltage Reference

OUTPUT

INPUT

8 LEAD SOIC 8 LEAD PDIP

3L TO-220 FRONT VIEW

TAB IS

GND

3L TO-263 FRONT VIEW

TAB IS

GND

TEMP.

3
2
1

3
2

1

OUTPUT

GND
INPUT

OUTPUT
GND

INPUT

RANGE

ADDITIONAL FEATURES (ADJ ONLY)

• 1.24V to 29V Programmable Output

• Error Flag Warning of Voltage Output Dropout

• Logic Controlled Electronic Shutdown

GENERAL DESCRIPTION

The AMS2954 series are micropower voltage regulators ideally suited for use in battery-powered systems. These devices
feature very low quiescent current (typ.75µA), and very low dropout voltage (typ.50mV at light loads and 380mV at 250mA)
thus prolonging battery life. The quiescent current increases only sligh tly in dropout. The AMS2954 has positive transient
protection up to 60V and can survive unregulated input transient up to 20V below ground. The AMS2954 was designed to
include a tight initial tolerance (typ. 0.5%), excellent load and line regulation (typ. 0.05%), and a very low output voltage
temperature coefficient, making these devices useful as a low-power voltage reference.
The AMS2954 is available in the 3L TO-220 package, 3L TO -263, SOT-223, TO-252 and in 8-pin plastic SOIC and DIP
packages. In the 8L SOIC and PDIP packages the following additional features are offered: an error flag output warns of a low
output voltage, often due to failing batteries on input; the logic-compatible shutdown inpu t enables the regu lator to be switched
on and off; the device may be pin-strapped for a, 2.5, 3.0V, 3.3V or 5V output, or programmed from 1.24V to 29V with an
external pair of resistors.

ORDERING INFORMATION

PACKAGE TYPE OPERATING

3 LEAD TO-220 3 LEAD TO-263 TO-252 SOT-223

AMS2954ACT-X AMS2954ACM-X AMS2954ACD-X AMS2954AC-X AMS2954ACS-X AMS2954CP-X IND.

AMS2954CT-X AMS2954CM-X AMS2954CD-X AMS2954C-X AMS2954CS-X AMS2954CP-X IND

X = 2.5V, 3.0V, 3.3V, 5.0V

SOT-223 TOP VIEW

PIN CONNECTIONS

8L SOIC/ 8L PDIP

1

OUTPUT

2

SENSE

SHUTDOWN

GROUND

3
4

8

INPUT

7

FEEDBACK

6V

TAP

5

ERROR

1

2

3

INPUT GND OUTPUT

TO-252 FRONT VIEW

TAB IS

GND

3
2
1

Advanced Monolithic Systems, Inc.

http://www.BDTIC.com/AMS

AMS2954

ABSOLUTE MAXIMUM RATINGS (Note 1)

Input Supply Voltage -0.3 to +30V Soldering Temperature (25 sec)
SHUTDOWN Input Voltage,
Error Comparator Output
Voltage,(Note 9)
FEEDBACK Input Voltage -1.5 to +30V
(Note 9) (Note 10)

OPERATING RATINGS (Note 1)

Power Dissipation Internally Limited
Junction Temperature
Storage Temperature

-65°C to +150°C

+150°C

ESD 2kV (T
AMS2954AC-X

Max. Input Supply Voltage 40V
Junction Temperature Range

) (Note 8)

J

-40°C to +125°C

AMS2954C-X

ELECTRICAL CHARACTERISTICS at V

Parameter

2.5 V Versions (Note 16)

Output Voltage

Output Voltage

3.0 V Versions (Note 16)
Output Voltage

Output Voltage

3.3 V Versions (Note 16)
Output Voltage

Output Voltage

5 V Versions (Note 16)
Output Voltage

Output Voltage

All Voltage Options
Output Voltage

Temperature Coefficient
Line Regulation (Note 14)

Load Regulation (Note 14)

Conditions

(Note 2)

TJ = 25°C (Note 3)

-25°C ≤TJ ≤85°C
Full Operating Temperature

Range
100 µA ≤IL ≤250 mA

TJ ≤T

TJ = 25°C (Note 3)

-25°C ≤TJ ≤85°C
Full Operating Temperature

Range
100 µA ≤IL ≤250 mA

TJ ≤T

TJ = 25°C (Note 3)

-25°C ≤TJ ≤85°C
Full Operating Temperature

Range
100 µA ≤IL ≤250 mA

TJ ≤T

TJ = 25°C (Note 3)

-25°C ≤TJ ≤85°C
Full Operating Temperature

Range
100 µA ≤IL ≤250 mA

TJ ≤T

(Note 12) (Note 4)
6V ≤Vin ≤30V (Note 15)

100 µA ≤IL ≤ 250 mA

JMAX

JMAX

JMAX

JMAX

=Vout+1V, Ta=25°C, unless otherwise noted.

s

AMS2954AC

Min. Typ. Max.

2.488

2.475

2.470

2.463

2.985

2.970

2.964

2.958

3.284

3.267

3.260

3.254

4.975

4.95

4.94

4.925

2.5

2.5

2.5

2.5

3.0

3.0

3.0

3.0

3.3

3.3

3.3

3.3

5.0

5.0

5.0

5.0

20 100 50 150

0.03 0.1 0.04 0.2 %

0.04 0.16 0.1 0.2 %

2.512

2.525

2.530

2.537 2.448

3.015

3.030

3.036

3.042 2.928

3.317

3.333

3.340

3.346 3.221

5.025

5.050

5.06

5.075 4.88

AMS2954C

Min. Typ. Max.

2.475

2.450

2.440

2.970

2.955

2.940

3.267

3.251

3.234

4.95

4.925

4.90

2.5

2.5

2.5

2.5

3.0

3.0

3.0

3.0

3.3

3.3

3.3

3.3

5.0

5.0

5.0

5.0

Advanced Monolithic Systems, Inc.

2.525

2.550

2.560

2.562

3.030

3.045

3.060

3.072

3.333

3.350

3.366

3.379

5.05

5.075

5.10

5.12

265°C

Units

V
V
V

V

V
V
V

V

V
V
V

V

V
V
V

V

ppm/°C

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AMS2954

ELECTRICAL CHARACTERISTICS (Note 2) (Continued)

A

Units

mV
mV

µA

mA

µV rms
µV rms
µV rms

V

µA

V
V

µA
µA

µA

= TJ =

PARAMETER

Dropout Voltage
(Note 5)

Ground Current

Current Limit

Thermal Regulation (Note 13) 0.05 0.2 0.05 0.2 %/W
Output Noise,

10Hz to 100KHz

8-Pin Versions only

Reference Voltage 1.22 1.235 1.25 1. 21 1.235 1.26 V
Reference Voltage Over Temperature (Note 7)

Feedback Pin Bias Current 40 60 40 60 nA

Reference Voltage Temperature
Coefficient

Feedback Pin Bias Current
Temperature Coefficient
Error Comparator

Output Leakage Current

Output Low Voltage

Upper Threshold Voltage
Lower Threshold Voltage
Hysteresis

Shutdown Input
Input logic Voltage

Shutdown Pin Input Current
(Note 3)

Regulator Output Current in
Shutdown (Note 3)

Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the
device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the
Electrical Characteristics tables.
Note 2: Unless otherwise specified all limits guaranteed for V
versions. Limits appearing in boldface type apply over the entire junction temperature range for operation. Limits appearing in normal type apply for T
25°C Additional conditions for the 8-pin versions are FEEDBACK tied to V

Note 3: Guaranteed and 100% production tested.
Note 4: Guaranteed but not 100% production tested. These limits are not used to calculate outgoing AQL levels.
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: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at
V

= ( V

IN

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
Note 7: V

+1)V. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = Vout/Vref = (R1 + R2)/R2. For

ONOM

≤ (Vin - 1V), 2.3 ≤Vin≤30V, 100µA≤IL≤ 250 mA, TJ ≤ T

ref ≤Vout

CONDITIONS

(Note 2)

IL = 100µ A
IL = 250 mA

IL = 100 µA
IL = 250 mA

V

= 0 200 500 200 500 mA

out

CL = 1µF
CL = 200 µF
CL = 13.3 µF
(Bypass = 0.01 µF pins 7 to 1)

( Note 12 )

V

= 30V

OH

Vin = 4.5V
IOL = 400µA
(Note 6) 40 60 40 60 mV
(Note 6) 75 95 75 95 mV
(Note 6) 15 15 mV

Low (Regulator ON)
High (Regulator OFF)

Vs = 2.4V
Vs = 30V

(Note 11) 3 10 3 10

= ( V

IN

as V

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

out

out

+1)V, IL = 100 µA and CL = 1 µF for 5V versions and 2.2µF for 3V and 3.3V

ONOM

TAP

.

JMAX

AMS2954AC

Min. Typ. Max.

1.19 1.27 1.185 1.285

0.01 1 0.01 1

2

, OUTPUT tied to SENSE and V

50

380

75
15

430
160
100

AMS2954AC

20 50 ppm/°C

0.1 0.1 nA/°C

150 250 150 250 mV

1.3

30
450

80

600
120

20

430

0.7

50
600

2

30

SHUTDOWN

AMS2954C

Min. Typ. Max.

75

≤ 0.8V.

50

380

15

160
100

AMS2954C

1.3

450

0.7

50
600

80

600
120

20

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AMS2954

Note 8: The junction-to-ambient thermal resistance are as follows:60°C/W for the TO-220 (T), 73°C/W for the TO-263 (M), 80°C/W for the TO-252 (D),

90°C/W for the SOT-223 (with package soldering to copper area over backside ground plane or internal power plane ϕ
depending on mounting technique and the size of the copper area), 105°C/W for the molded plastic DIP (P) and 160°C/W for the molded plastic SO-8 (S).

Note 9: May exceed input supply voltage.
Note 10: When used in dual-supply systems where the output terminal sees loads returned to a negative supply, the output voltage should be diode-clamped to

ground.
Note 11: V

≥ 2V, Vin ≤ 30V, V

shutdown

=0, Feedback pin tied to 5V

out

TAP

.

Note 12: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.
Note 13: 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 effects. Specifications are for a 50mA load pulse at V

=30V (1.25W pulse) for T =10 ms.

IN

Note 14: 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 15: Line regulation for the AMS2954 is tested at 150°C for I

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

L

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

BLOCK DIAGRAM AND TYPICAL APPLICATIONS

AMS2954-XX

3 Lead Packages

UNREGULATED DC

+

+

-

+

1.23V
REFERENCE

INPUT

ERROR
AMPLIFIER

OUTPUT

GROUND

V

OUT

IL≤

+

SEE APPLICATION

150mA

HINTS

FROM
CMOS

OR TTL

UNREGULATED DC

+

FEED­BACK

3

SHUT­DOWN

ERROR DETECTION COMPARATOR

50mV

+

+

1.23V
REFERENCE

can vary from 46°C/W to >90°C/W

JA

AMS2954-XX

8 Lead Packages

INPUT OUTPUT

+

­ERROR

AMPLIFIER

+

-

187

SENSE

V

TAP

ERROR

GROUND

2

6

5

V

OUT

IL≤

150mA

SEE APPLICATION

+

Ω

330k

4

HINTS

TO CMOS
OR TTL

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TYPICAL PERFORMANCE CHARACTERISTICS

Quiescent Current

20

10

1

GROUND CURRENT (mA)

0.1

270
240
210
180
150

120

90
75
60
45

INPUT CURRENT (mA)

30
15

0

50 100

1

LOAD CURRENT (mA)

Input Current

1 23456789100

INPUT VOLTAGE (V)

150 200

IO=250mA

250

Dropout Characteristics

6

5V OUTPUT

5

4

3

2

OUTPUT VOLTAGE (V)

1

0

1

0

INPUT VOLTAGE (V)

Temperature Drift of 3
Representative Units

5.06

5.04

5.02

5.0

4.98

OUTPUT VOLTAGE (V)

4.96

4.94

5V OUTPUT5V OUTPUT 5V OUTPUT

-75 0 25 50 75 100 125

-50 -25
TEMPERATURE (° C)

IO=1mA

IO=250mA

345 6 123456789100

2

0.2%

150

AMS2954

Input Current

250
225

200

A)

µ

175
150

125
100

INPUT CURRENT (

160
140

A)

µ

120
100

QUIESCENT CURRENT (

5V OUTPUT

RL=

∞

75
50
25

0

INPUT VOLTAGE (V)

Quiescent Current

80
60
40
20

0

012345678

INPUT VOLTAGE (V)

IL= 0mA

IL= 1 mA

Quiescent Current

120

5V OUTPUT

110

A)

µ

100

90

80

70

60

QUIESCENT CURRENT (

50

-75

-50 -25

0 25 50 75 100 125

TEMPERATURE (° C)

IL= 100µA

VIN= 6V

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150

Quiescent Current

5V OUTPUT

30

25

20

15

10

QUIESCENT CURRENT (mA)

5

-75

-50 -25

0 25 50 75 100 12535150

TEMPERATURE (° C)

VIN= 6V
IL= 250mA

Quiescent Current

24

5V OUTPUT

21
18
15
12

9
6
3

QUIESCENT CURRENT (mA)

0

012345678

INPUT VOLTAGE (V)

IL= 250mA