ADMOS AMS2501CS-5.0, AMS2501CS-3.5, AMS2501CS-3.3, AMS2501CS-3.0, AMS2501CS-2.85 Datasheet

Advanced AMS2501/AMS2502
Monolithic 1A VERY LOW DROPOUT VOLTAGE REGULATORS

Systems

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/AMS2502 series of adjustable and fixed low dropout voltage regulators are designed to provide 1A output
current. The dropout voltage of the device is 100mV at light loads and rising to 200mV at 500mA output current. A second
input voltage of 1.2V or greater than the output is required to achieve this dropout. The AMS2501/AMS2502 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. AMS2502 has an additional feature of an On/Off pin to keep the device in stand-by mode.
The typical load regulation, measured at the Sense pin, for a load current step of 100mA to 1A is less than 1mV.
The AMS2501/AMS2502 series has fast transient response. On the AMS2502 the reference voltage is brought out to allow
the user to add a bypass capacitor for lower noise and transient response improvement.
The AMS2501/AMS2502 series are ideal for generating supplies of 1.25V to 3V where both 5V and 3.3V supplies are
available.
The AMS2501/AMS2502 devices are offered in 8 lead SOIC package.

•• Post Regulators for Switching Supplies

ORDERING INFORMATION: PIN CONNECTIONS

PACKAGE TYPE OPERATING JUNCTION

8 LEAD SO-8

AMS2501CS AMS2502CS
AMS2501CS-1.5 AMS2502CS-1.5
AMS2501CS-1.8 AMS2502CS-1.8
AMS2501CS-2.5 AMS2502CS-2.5
AMS2501CS-2.85 AMS2502CS-2.85
AMS2501CS-3.0 AMS2502CS-3.0
AMS2501CS-3.3 AMS2502CS-3.3
AMS2501CS-3.5 AMS2502CS-3.5
AMS2501CS-5.0 AMS2502CS-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

POWER IN

OUTPUT
OUTPUT

SENSE

POWER IN

OUTPUT
OUTPUT

SENSE

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone [phone] Fax [phone]

AMS2501 8L SOIC

1
2
3
4

8

CONTROL IN

7

N/C
6 ADJ/GND
5

N/C

Top View

AMS2502 8L SOIC

1
2
3
4

8

CONTROL IN
7

BYPASS
6 ADJ/GND
5

ON/OFF

Top View

AMS2501/AMS2502

Junction Temperature Range

ABSOLUTE MAXIMUM RATINGS (Note 1)

V

Input Voltage 7V Soldering information

POWER

V
Operating
Control Section
Power Transistor
Storage temperature

CONTROL

Input Voltage 13V Lead Temperature (10 sec)

Thermal Resistance

0°C to 125°C

SO-8 package

0°C to 150°C

- 65°C to +150°C

260°C

ϕ JA= 160°C/W

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at I

Parameter Device Conditions Min Typ Max Units

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

LOAD

Reference Voltage AMS2501/AMS2502 V

Output Voltage AMS2501/AMS2502-1.5 V

AMS2501/AMS2502-1.8 V

AMS2501/AMS2502-2.5 V

AMS2501/AMS2502-2.85 V

AMS2501/AMS2502-3.0 V

AMS2501/AMS2502-3.3 V

AMS2501/AMS2502-3.5 V

AMS2501/AMS2502-5.0 V

Line Regulation AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0

Load Regulation AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0

Minimum Load

AMS2501/AMS2502 V

Current
Control Pin Current

(Note 4)

Ground Pin Current
(Note 4)

AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0
AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0

Adjust Pin Current AMS2501/AMS2502 V
Current Limit AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0

Ripple Rejection AMS2501/AMS2502-1.5/-

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0

= 2.75V, V

CONTROL

V

= 2.7V to 12V, V

CONTROL

I

= 10mA to 1A

LOAD

= 4V, V

CONTROL

V

= 3V, V

CONTROL

= 4V, V

CONTROL

V

= 3V, V

CONTROL

= 5V, V

CONTROL

V

= 4V, V

CONTROL

= 5.35V, V

CONTROL

V

= 4.4V, V

CONTROL

= 5.5V, V

CONTROL

V

= 4.5V, V

CONTROL

= 5.8V, V

CONTROL

V

= 4.8V, V

CONTROL

= 6V, V

CONTROL

V

= 5V, V

CONTROL

= 7.5V, V

CONTROL

V

= 6.5V, V

CONTROL

I

= 10 mA , 1.5V≤ (V

LOAD

0.8V≤ (V

POWER

V

= V

CONTROL

I

= 10mA to 1A

LOAD

= 5V, V

CONTROL

V

= V

CONTROL

I

= 10mA

LOAD

V

= V

CONTROL

I

= 10mA

LOAD

= 2.75V, V

CONTROL

V

=V

POWER

OUT

V

= V

CONTROL

I

= 1A

LOAD

POWER
POWER

POWER
POWER

POWER
POWER

POWER
POWER

- V
+ 2.5V, V

OUT

POWER

+ 2.5V, V

OUT

+ 2.5V, V

OUT

+ 0.8V

POWER

POWER

POWER

POWER

POWER
POWER

POWER
POWER

POWER
POWER

OUT

POWER

= V

=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
=3.5V, I

=3.8V, I
=3.8V, I

=4.1V, I

=4V, I
=4.3V, I

=5.5V, I
=5.8V, I

CONTROL

) ≤ 5.5V

POWER

=3.3V, V

POWER

POWER

= 2.05V, I

+ 2.5V, V

OUT

= 10mA

LOAD

=3.3V to 5.5V,

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

= 0mA

LOAD

= 0mA to 1A

LOAD

- V

) ≤ 12V

OUT

=V

+ 0.8V,

OUT

= 0V (Note 3)

ADJ

=V

+ 0.8V,

OUT

=V

+ 0.8V,

OUT

LOAD

RIPPLE

= 10mA

= 1V

P-P

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

1.262

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

1 3

1 5

5 10

10 16

6 10

40 120

1.0 1.2 1.5

60 80 dB

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

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone [phone] Fax [phone]

AMS2501/AMS2502

POWER

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at I

Parameter Device Conditions Min Typ Max Units

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

OUT

Thermal Regulation AMS2501/AMS2502 TA = 25°C, 30ms pulse, I

Dropout Voltage

Control Dropout
(V

Power Dropout
(V

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

CONTROL

POWER

- V

- V

OUT

OUT

AMS2501/AMS2502/-1.5/-

)

1.8/-2.5/-2.85/-3.0/-3.3/-

3.5/-5.0
AMS2501/AMS2502/-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

LOAD

LOAD

LOAD

= 10mA
= 1A

= 1A

1.00

1.15

.05
.30

1.15

1.30

0.15

0.50

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/AMS2502 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

device of the AMS2501/AMS2502. 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.

On/Off (Pin 5 AMS2502 only): This pin puts the device
in a stand-by mode.

Reference (Pin 7 AMS2502 only): This pin allows the
user to add a bypass capacitor on the reference voltage.

(Pin 1): This pin is the collector to the power

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.

GND (Pin 6): For fixed voltage devices this is the
bottom of the resistor divider that sets the output
voltage.

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.

V
V

V
V

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone [phone] Fax [phone]