Advanced Monolithic Systems AMS2908 Service Manual

http://www.BDTIC.com/AMS

Advanced AMS2908
Monolithic 800mA LOW DROPOUT VOLTAGE REGULATOR

Systems
RoHS compliant

FEATURES APPLICATIONS

•••• Three Terminal Adjustable or Fixed Voltages* •••• High Efficiency Linear Regulators

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

• Output Current of 800mA •••• 5V to 3.3V Linear Regulator

•

•

•

•••• Operates Down to 1V Dropout •••• Battery Chargers

•••• Line Regulation: 0.2% Max. •••• Active SCSI Terminators

•••• Load Regulation: 0.4% Max. •••• Power Management for Notebook

•••• SOT-223 and TO-252 package available •••• Battery Powered Instrumentation

GENERAL DESCRIPTION

The AMS2908 series of adjustable and fixed voltage regulators are designed to provide 800mA output current and to operate

own to 1V input-to-output differential. The dropout voltage of the device is guaranteed maximum 1.3V at maximum output

d
current, decreasing at lower load currents.
On-chip trimming adjusts the reference voltage to 1%. Current limit is also trimmed, minimizing the stress under overload
conditions on both the regulator and power source circuitry.
The AMS2908 devices are pin compatible with other three-terminal regulators and are offered in the low profile surface mount
SOT-223 package and in the TO-252 (DPAK) plastic package.

ORDERING INFORMATION:

AMS2908CD AMS2908
AMS2908CD-1.5 AMS2908-1.5
AMS2908CD-1.8 AMS2908-1.8
AMS2908CD-2.5 AMS2908-2.5
AMS2908CD-2.85 AMS2908-2.85
AMS2908CD-3.3 AMS2908-3.3
AMS2908CD-5.0 AMS2908-5.0
*For additional available fixed voltages contact factory.

PACKAGE TYPE OPERATING JUNCTION

TO-252 SOT-223

TEMPERATURE RANGE

-40 to 125° C

-40 to 125° C

-40 to 125° C

-40 to 125° C

-40 to 125° C

-40 to 125° C

-40 to 125° C

PIN CONNECTIONS

FIXED VERSION

1- VIN
2- Ground
3- V

OUT

ADJUSTABLE VERSION

1- VIN

- Adjust

2
3- V

OUT

•••• Post Regulators for Switching Supplies

SOT-223 Top View

TO-252 FRONT VIEW

1

2

3

3
2
1

updated April 24, 2009

http://www.BDTIC.com/AMS

AMS2908

ABSOLUTE MAXIMUM RATINGS (Note 1)

Power Dissipation Internally limited

OPERATING CONDITIONS (Note 1)

Maximum Input Voltage 15V Input Voltage Range 2.6V to 12V
Thermal Resistance Junction Temperature
SOT-89 package
TO-252 package
SOT-223 package
Storage temperature

ϕ JA= 110°C/W

ϕ JA= 80°C/W

ϕ JA= 90°C/W*

65°C to +150°C

-

Control Section -40ºC to 125 ºC
Power Transistor -40ºC to 150 ºC
Lead Temperature (Sold. 25 sec) 265 ºC

* With package soldering to copper area over backside ground
plane or internal power plane ϕ
46°C/W to >90°C/W depending on mounting technique and the
size of the copper area

can vary from

JA

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at I

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

OUT

Parameter

Device Conditions Min Typ Max Units

Reference Voltage
(Note 2)

Output Voltage
(Note 2)

Line Regulation AMS2908

AMS2908-1.5

AMS2908-1.8

AMS2908-2.5

AMS2908-2.85

AMS2908-3.3

AMS2908-5.0

Load Regulation

(Notes 2, 3)

AMS2908-1.5

AMS2908-1.8

AMS2908-2.5

AMS2908 I

AMS2908-1.5

AMS2908-1.8

AMS2908-2.5

AMS2908-2.85

AMS2908-3.3

AMS2908-5.0

AMS2908

= 10 mA

OUT

10mA ≤ I

0 ≤ I

0 ≤ I

0 ≤ I

0 ≤ I

0 ≤ I

0 ≤ I

I

LOAD

3.0V≤ VIN ≤ 12V

3.0V≤ VIN ≤ 12V

4.0V≤ VIN ≤ 12V

4.35V≤ VIN ≤ 12V

4.75V≤ VIN ≤ 12V

6.5V≤ VIN ≤ 12V

(VIN - V

VIN = 5V, 0 ≤ I

VIN = 5V, 0 ≤ I

VIN = 5V, 0 ≤ I

≤ 800mA, 1.5V≤ (VIN - V

OUT

≤ 800mA , 4.35V≤ VIN ≤ 12V

OUT

≤ 800mA , 4.35V≤ VIN ≤ 12V

OUT

≤ 800mA , 4.35V≤ VIN ≤ 12V

OUT

≤ 800mA , 4.35V≤ VIN ≤ 12V

OUT

≤ 800mA , 4.75V ≤ VIN ≤ 12V

OUT

≤ 800mA , 6.5V ≤ VIN ≤ 12V

OUT

= 10 mA , 1.5V≤ (VIN - V

) =3V, 10mA ≤ I

OUT

≤ 800mA

OUT

≤ 800mA

OUT

≤ 800mA

OUT

OUT

≤ 800mA

OUT

OUT

) ≤ 12V

) ≤ 12V

updated April 24, 2009

1.238

1.225

1.485

1.476

1.782

1.772

2.475

2.460

2.82

2.79

3.267

3.235

4.950

4.900

0.015

0.3

0.3

0.3

0.3

0.5

0.5

3

3

3

1.250

1.250

1.500

1.500

1.800

1.800

2.500

2.500

2.850

2.850

3.300

3.300

5.000

5.000

0.035

0.6

0.6

0.6

0.6

1.0

1.0

0.1

0.2

6

6

6

1.262

1.270

1.515

1.524

1.818

1.828

2.525

2.560

2.88

2.91

3.333

3.365

5.050

5.100

0.2

0.2

5
6

5
6

6
6

6
6

10
10

10
10

0.3

0.4

10
20

10
20

12
20

V
V

V
V

V
V

V
V

V
V

V
V

V
V

%
%

mV
mV

mV
mV

mV
mV

mV
mV

mV
mV

mV
mV

%
%

mV
mV

mV
mV

mV
mV

http://www.BDTIC.com/AMS

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at I

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

OUT

AMS2908

Parameter

Device Conditions Min Typ Max Units

Load Regulation

(Notes 2, 3)

Dropout Voltage

(V

- V

OUT

)

IN

Current Limit

Minimum Load
Current

Quiescent Current AMS2908-1.5/-1.8/-2.5/-

Ripple Rejection AMS2908

AMS2908-1.5/-1.8/-2.5/-

AMS2908-3.3

AMS2908-5.0

Thermal Regulation AMS2908 TA = 25°C, 30ms pulse 0.008 0.04 %W

AMS2908-2.85

AMS2908-3.3

AMS2908-5.0

AMS2908-1.5/-1.8/-2.5/-

2.85/-3.3/-5.0

AMS2908-1.5/-1.8/-2.5/-

2.85/-3.3/-5.0

VIN = 5V, 0 ≤ I

VIN = 5V, 0 ≤ I

VIN = 8V, 0 ≤ I

∆V

OUT

(VIN - V

AMS2908 (VIN - V

VIN ≤ 12V

2.85/-3.3/-5.0

f =120Hz , C
(VIN-V

f =120Hz , C

2.85

VIN = 6V

f =120Hz , C
VIN = 6.3V

f =120Hz , C
VIN = 8V

≤ 800mA

OUT

≤ 800mA

OUT

≤ 800mA

OUT

, ∆V

= 1%, I

REF

) = 5V

OUT

) = 12V (Note 5)

OUT

= 25µF Tantalum, I

OUT

) = 3V, C

OUT

= 25µF Tantalum, I

OUT

= 25µF Tantalum, I

OUT

= 25µF Tantalum, I

OUT

= 800mA (Note 4)

OUT

=25µF

ADJ

= 800mA,

OUT

= 800mA,

OUT

= 800mA

OUT

= 800mA

OUT

3

3

5

10

1.1 1.3

6

7

12
20

15
25

20

35

900 1,100 1,500

5 10

60 75

60

60 72

60 68

5

72

dB

10

mV
mV

mV
mV

mV
mV

V

mA

mA

mA

dB

dB

dB

Adjust Pin Current AMS2908

Adjust Pin Current

AMS2908

Change

Temperature Stability

10mA ≤ I

10mA ≤ I

≤ 800mA , 1.5V≤ (VIN - V

OUT

≤ 800mA , 1.5V≤ (VIN - V

OUT

OUT

OUT

) ≤ 12V

) ≤ 12V

55

0.2

0.5

120

5

µA
µA

µA

%

Long Term Stability TA =125°C, 1000Hrs 0.3 1 %

RMS Output Noise

(% of V

OUT

)

Thermal Resistance
Junction-to-Case

TA = 25°C , 10Hz ≤ f ≤ 10kHz

0.003

15 °C/W

%

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: Line and Load regulation are guaranteed up to the maximum power dissipation of 1.2 W. Power dissipation is determined by the input/output

differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range.

Note 3: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at a constant

junction temperature by low duty cycle pulse testing. Load regulation is measured at the output lead ~1/8” from the package.

Note 4: Dropout voltage is specified over the full output current range of the device.
Note 5: Minimum load current is defined as the minimum output current required to

guaranteed to regulate if the output current is greater than 10mA.

maintain regulation. When 1.5V ≤ (VIN - V

) ≤ 12V the device is

OUT

updated April 24, 2009