Advanced Monolithic Systems AMS2501 Service Manual

http://www.BDTIC.com/AMS

Advanced AMS2501
Monolithic 1A VERY LOW DROPOUT VOLTAGE REGULATOR

Systems
RoHS compliant

FEATURES APPLICATIONS

•••• Adjustable or Fixed Output •••• High Efficiency Current Regulators

1.5V, 1.8V, 2.5V, 2.85V, 3.0V, 3.3V, 3.5V and 5.0V

•••• Output Current of 1A •••• Audio/Video/Modem Card Supply

•••• Low Dropout, typ. 200mV at 500mA Output Current •••• Adjustable Power Supply

•••• Fast Transient Response •••• Notebook/Personal Computer Supplies

•••• Remote Sense

GENERAL DESCRIPTION

The AMS2501 series are adjustable and fixed low dropout voltage regulators are designed to provide 1A output current. The

ropout voltage of the device is 100mV at light loads and rising to 200mV at 500mA output current. A second input voltage of

d

1.2V or greater than the output is required to achieve this dropout. The AMS2501 can also be used as a single supply device by
connecting pin1 and pin 8 together. In this case the dropout voltage will be typically 1.2V.
New features have been added to the AMS2501: a remote Sense pin is brought out virtually eliminating output voltage
variations due to load changes. The typical load regulation, measured at the Sense pin, for a load current step of 100mA to 1A
is less than 1mV. The AMS2501 series has fast transient response and are ideal for generating supplies of 1.25V to 3V where
both 5V and 3.3V supplies are available.
The AMS2501 devices are offered in 8 lead EDP package.

ORDERING INFORMATION: PIN CONNECTIONS

OPERATING

UNCTION

J

AMS2501CS
AMS2501CS-1.5
AMS2501CS-1.8
AMS2501CS-2.5
AMS2501CS-2.85
AMS2501CS-3.0
AMS2501CS-3.3
AMS2501CS-3.5
AMS2501CS-5.0

TEMPERATURE

RANGE

0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C
0 to 125° C

•••• Post Regulators for Switching Supplies

AMS2501 8L SOIC EDP

POWER IN

OUTPUT

OUTPUT

SENSE

1

2

3

4

8

CONTROL IN

7

N/C

6 ADJ/GND

5

N/C

Top View

updated April 24, 2009

http://www.BDTIC.com/AMS

AMS2501

ABSOLUTE MAXIMUM RATINGS (Note 1)

V

Input Voltage 7V Soldering information

POWER

V

CONTROL

Input Voltage 13V Lead Temperature (25 sec)

265°C

Operating Junction Temperature Range Thermal Resistance
Control Section
Power Transistor
Storage temperature

0°C to 125°C

0°C to 150°C

- 65°C to +150°C

SO-8 package

ϕ JA= 60°C/W

CTRICAL CHARACTERISTICS

ELE

Electrical Characteristics at I

Parameter Device Conditions Min Typ Max Units

Reference Voltage AMS2501 V

Output Voltage

Line Regulation AMS2501-1.5/-1.8/-2.5/-

Load Regulation

Minimum Load
Current

Control Pin Current

(Note 4)

Ground Pin Current

(Note 4)

Adjust Pin Current AMS2501 V

Current Limit

Ripple Rejection AMS2501-1.5/-1.8/-2.5/-

AMS2501-1.5 V

AMS2501-1.8 V

AMS2501-2.5 V

AMS2501-2.85 V

AMS2501-3.0 V

AMS2501-3.3 V

AMS2501-3.5 V

AMS2501-5.0 V

2.85/-3.0/-3.3/-3.5/-5.0

AMS2501-1.5/-1.8/-2.5/-

2.85/-3.0/-3.3/-3.5/-5.0

AMS2501 V

AMS2501-1.5/-1.8/-2.5/-

2.85/-3.0/-3.3/-3.5/-5.0

AMS2501-1.5/-1.8/-2.5/-

2.85/-3.0/-3.3/-3.5/-5.0

AMS2501-1.5/-1.8/-2.5/-

2.85/-3.0/-3.3/-3.5/-5.0

2.85/-3.0/-3.3/-3.5/-5.0

= 0 mA, and TJ = +25°C unless otherwise specified.

LOAD

CONTROL

V

CONTROL

I

= 10mA to 1A

LOAD

CONTROL

V

CONTROL

CONTROL

V

CONTROL

CONTROL

V

CONTROL

CONTROL

V

CONTROL

= 2.75V, V
= 2.7V to 12V, V

= 4V, V
= 3V, V

= 4V, V
= 3V, V

= 5V, V
= 4V, V

= 5.35V, V
= 4.4V, V

POWER

POWER

POWER

POWER

POWER

POWER

POWER

POWER

POWER

=2V, I

POWER

=2.V, I
=2.3V, I

=2.V, I
=2.3V, I

=3.3V, I
=3.3V, I

=3.35V, I

=3.7V, I

LOAD

=3.3V to 5.5V,

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

LOAD

LOAD

1A

CONTROL

V

CONTROL

= 5.5V, V
= 4.5V, V

POWER

POWER

=3.5V, I
=3.8V, I

LOAD

LOAD

1A

CONTROL

V

CONTROL

= 5.8V, V
= 4.8V, V

POWER

POWER

=3.8V, I
=4.1V, I

LOAD

LOAD

1A

CONTROL

V

CONTROL

CONTROL

V

CONTROL

= 6V, V
= 5V, V

= 7.5V, V
= 6.5V, V

POWER

POWER

POWER

POWER

=4V, I
=4.3V, I

=5.5V, I
=5.8V, I

LOAD

LOAD

= 0mA

LOAD

LOAD

= 0mA to 1A

1A

I

= 10 mA , 1.5V≤ (V

LOAD

0.8V≤ (V

V

I

V

I

V

I

V

POWER

CONTROL

= 10mA to 1A

LOAD

CONTROL

CONTROL

= 10mA

LOAD

CONTROL

= 10mA

LOAD

CONTROL

=V

POWER

= V

= 5V, V

= V

= V

= 2.75V, V

OUT

- V

+ 2.5V, V

OUT

POWER

+ 2.5V, V

OUT

+ 2.5V, V

OUT

+ 0.8V

OUT

POWER

) ≤ 5.5V

=3.3V, V

CONTROL

POWER

POWER

POWER

= 2.05V, I

- V

=V

OUT

= 0V (Note 3)

ADJ

=V

OUT

=V

OUT

V

I

CONTROL

= 1A

LOAD

= V

POWER

= V

+ 2.5V, V

OUT

= 10mA

= 0mA

= 0mA to

= 0mA
= 0mA to

= 0mA
= 0mA to

= 0mA
= 0mA to

) ≤ 12V

OUT

+ 0.8V,

+ 0.8V,

+ 0.8V,

= 10mA

LOAD

= 1V

RIPPLE

1.238

1.232

1.491

1.485

1.782

1.773

2.485

2.475

2.821

2.833

2.982

2.970

3.280

3.235

3.479

3.430

4.930

4.950

1.250

1.250

1.500

1.500

1.800

1.800

2.500

2.500

2.850

2.850

3.000

3.000

3.300

3.300

3.500

3.500

5.000

5.000

1 3

1

5 10

10 16

6 10

40 120

1.0 1.2 1.5

60 80 dB

P-P

1.262

1.268

1.509

1.515

1.818

1.827

2.515

2.525

2.879

2.867

3.018

3.030

3.320

3.333

3.521

3.535

5.030

5.050

5

V
V

V
V

V
V

V
V

V
V

V
V

V
V

V
V

V
V

mV

mV

mA

mA

mA

µA

A

updated April 24, 2009

http://www.BDTIC.com/AMS

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at I

= 0 mA, and TJ = +25°C unless otherwise specified.

OUT

AMS2501

Parameter

Device Conditions Min Typ Max Units

Thermal Regulation AMS2501 TA = 25°C, 30ms pulse, I

Dropout Voltage

Control Dropout
(V

Power Dropout
(V

CONTROL

POWER

- V

- V

OUT

OUT

)

AMS2501-1.5/-1.8/-2.5/-

)

2.85/-3.0/-3.3/-3.5/-5.0

AMS2501-1.5/-1.8/-2.5/-

2.85/-3.0/-3.3/-3.5/-5.0

Note 2

V

POWER

V

POWER

V

CONTROL

=V

=V

=V

OUT

OUT

OUT

+ 0.8V, I

+ 0.8V, I

+ 2.5V, I

= 1A 0.002 0.020 %W

LOAD

= 10mA

LOAD

= 1A

LOAD

= 1A

LOAD

1.00

1.15

.05

.30

1.15

1.30

0.15

0.50

V

V

V

V

Parameters identified with boldface type apply over the full operating temperature range.

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test conditions, see the

Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed.

Note 2: Unless otherwise specified V

OUT

= V

. For the adjustable device V

SENSE

ADJ

= 0V.

Note 3: The dropout voltage for the AMS2501 is caused by either minimum control voltage or minimum power voltage. The specifications represent the

minimum input/output voltage required to maintain 1% regulation.

Note 4: For the adjustable device the minimum load current is the minimum current required to maintain regulation. Normally the current in the resistor

divider used to set the output voltage is selected to meet the minimum load current requirement.

Note 5: The control pin current is the drive current required for the output transistor. This current will track output current with a ratio of about 1:100. The

minimum value is equal to the quiescent current of the device.

PIN FUNCTIONS

V

POWER

(Pin 1): This

pin is the collector to the power
device of the AMS2501. The output load current is
supplied through this pin. The voltage at this pin must be
between 0.1V and 0.8V greater than the output voltage for
the device to regulate.

Output (Pin 2 and 3): These are the power output of the
device. Pin 2 and 3 are fused together and with the package
paddle serving also as heat sink.

Sense (Pin 4): This pin is the positive side of the reference
voltage for the device. With this pin it is possible to Kelvin
sense the output voltage at the load.

N/C (Pin 5): Not Connect.

updated April 24, 2009

Adjust (Pin 6): This pin is the negative side of the
reference voltage for the device. Adding a small bypass
capacitor from the Adjust pin to ground improves the
transient response. For fixed voltage devices the Adjust
pin is also brought out to allow the user to add a bypass
capacitor.

N/C (Pin 7): Not Connect.

V

CONTROL

(Pin 8): This pin is the supply pin for the

control circuitry of the device. The current flow into this
pin will be about 1% of the output current. The voltage
at this pin must be between 1.0V and 1.3V greater than
the output voltage for the device to regulate.