GS1085CM-18/31F-E3 - Vishay Presicion Group

3A Low Dropout Positive Adjustable Regulator

Description

The GS1085 is a low dropout three terminal regulator with

3A output current capability. The output voltage is

adjustable with the use of a resistor divider. For fixed output

voltage versions, the output voltage is internally set at

1.8V, 2.5V, or 3.3V. Dropout is guaranteed at a maximum

of 1.3V at maximum output current. Its low dropout voltage

and fast transient response make it ideal for low voltage

microprocessor applications. Internal current and thermal

limiting provides protection against any overload condition

that would create excessive junction temperatures.

Applications

• Post Regulator for Switching Supply

• Microprocessor Power Supplies

• Constant-Current Regulators

• Motherboard I/O Power Supplies

Mechanical Data

Case: TO-220AB, TO-263AB (D2PAK),

TO-252 (DPAK)

High temperature soldering guaranteed:

260°C/10 seconds at terminals

Case outlines are on the back page

+--

For

fixed

voltage

device

Thermal

Limit

Current

Amp

Current

Limit

VOUT

VIN

ADJ GND

VREF

1.25V

55µA

Functional Block Diagram

Features

• Dropout Voltage 1.3V at 3A Output Current

• Fast Transient Response

• Line Regulation typically at 0.015%

• Load Regulation typically at 0.1%

• Internal thermal and current limiting

• Adjustable Output Voltage or Fixed 1.8V, 2.5V, 3.3V

• Standard 3-Pin Power Packages

TO-220AB TO-263AB

(D2Pak)

GS1085CT GS1085CMGS1085CE

TO-252

(DPak)

Pin Definition

1. Adjust/Gnd.

2. Vout (tab)

3. Vin

GS1085

Vishay Siliconix

Document Number 74821 www.vishay.com

07-Mar-05 1

Maximum Ratings and Thermal Characteristics (TA= 25°C unless otherwise noted)

Parameter Symbol Value Unit

Vin Pin to ADJ/GND Pin Vin 7 V

Thermal Resistance – Junction to Case

TO-220AB 3.0

TO-252 RθJC 8.0 °C/W

TO-263AB 3.0

Operating Junction Temperature Range TJ0 to +125 °C

Storage Temperature Range Tstg –65 to 150 °C

Electrical Characteristics(1) TJ= 25°C (2), VIN = 5V, Io= 10mA unless otherwise noted.

Parameter Symbol Test Conditions Min Typ Max Unit

Reference Voltage VREF TJ= 25°C 1.225 1.250 1.275 V

0°C ≤TJ≤125°C 1.213 1.250 1.288

GS1085-1.8 VIN = 5V 1.76 1.8 1.84

Output Voltage VOUT GS1085-2.5 VIN = 5V 2.45 2.5 2.55 V

GS1085-3.3 VIN = 7V 3.23 3.3 3.37

GS1085 0.98VNVN1.02VN

0°C ≤TJ≤125°C

2.75V ≤VIN ≤7V

Line Regulation REGline TJ= 25°C 0.015 0.2 % VO

0°C ≤TJ≤125°C 0.035 0.2

10mA ≤Io≤3A

Load Regulation REGload TJ= 25°C 0.1 0.3 % VO

0°C ≤TJ≤125°C 0.2 0.4

0°C ≤TJ≤125°C

Dropout Voltage VDROP Io= 3A 1.2 1.3 V

Io= 2A 1.1 1.2

Io= 1A 1.0 1.1

Output Current Io0°C ≤TJ≤125°C 3.0 4.0 – A

2.75 ≤Vin ≤7V

Adjust Pin Current Iadj 10mA ≤Io≤3A – 55 120 µA

0°C ≤TJ≤125°C

2.75 ≤Vin ≤7V

Adjust Pin Current Change ∆Iadj 10mA ≤Io≤3A – 0.2 5 µA

0°C ≤TJ≤125°C

Temperature Stability TSIo= 0.5A –0.5 – %VO

0°C ≤TJ≤125°C

Minimum Load Current ILMIN 0°C ≤TJ≤125°C – 5 10 mA

Adjustable Version

GS1085

Vishay Siliconix

www.vishay.com Document Number 74821

207-Mar-05

Electrical Characteristics(con’t.)(1) TJ= 25°C (2), VIN = 5V, Io= 10mA unless otherwise noted.

Parameter Symbol Test Conditions Min Typ Max Unit

Quiescent Current IQ0°C ≤TJ≤125°C – 10 14 mA

Fixed Voltage Version

RMS Output Noise N 10HZ≤f ≤10 kHZ–0.003 – %VO

Ripple Rejection Ratio RR f = 120 HZ, CO= 25µF60 72 – dB

Cadj = 25µF

Thermal Regulation RTH TA= 25°C, 30ms Pulse – 0.02 0.05 %/W

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

Notes:

(1) All parameters, except nominal output voltage are specified for the variable voltage version, allowing a wider Vin Range.

The specified limits also apply for the fixed voltage versions over the allowable input voltage range: GS1085-1.8 (3.2V - 7.0V), GS1085-2.5 (3.9V - 7.0V),

GS1085-3.3 (4.75V - 7.0V).

(2) To maintain the specified junction temperatures, low duty cycle pulse testing is required for most parameters.

Notes:

VREF = VOUT – VADJ = 1.25V (typ.)

VOUT = VREF x (1+R2/R1) + IADJ x R2

IADJ = 55µA(typ.)

(1) C1 needed if device is far away from filter capacitors

(2) C2 required for stability

Typical Application Circuit

VIN

VOUT

3.3V

10µF

ADJ VREF

125Ω

205Ω

GS1085

Adjustable Voltage Regulator

VIN

5V VOUT

10µF

GS1085-1.8

GS1085-2.5

GS1085-3.3

Fixed Voltage Regulator

Document Number 74821 www.vishay.com

07-Mar-05 3

GS1085

Vishay Siliconix

--0.10

0.10

--0.05

0.05

--0.15

--0.20 20 40 60 80 100 120

Fig. 2 – Load Regulation

vs. Temperature

Output Voltage Deviation (%)

Temperature (°C)

100

--50 --25 0 25 50 75 100 125

Fig. 4 – Adjust Pin Current

Adjust Pin Current (µA)

Temperature (°C)

--1.0

--0.75

--0.5

--0.25

0.25

0.5

0.0

0.75

1.0

--20 0 20 40 60 80 100 120 140

Fig. 5 – Temperature Stability

Output Voltage Deviation (%)

Temperature (°C)

Iout = 0.5A

IOUT = 3A

0.5 1.0 2 2.5 3.01.5

Minimum Differential Voltage (V)

Output Current (A)

1.20

1.18

1.16

1.14

1.12

1.10

1.08

1.06

1.22

100 1K 100K10K 1M

Fig. 6 – Ripple Rejection

(with Cadj 25µF)

Ripple Rejection (dB)

Frequency (Hz)

12 4563

Fig. 3 – Minimum Load Current

(Adjustable Version)

Minimum Operating Current (mA)

Input / Output Differential Voltage (V)

TJ = 0°C

TJ = 25°C

TJ = 125°C

Fig. 1 – Dropout Voltage

vs. Output Current

COUT = 25µF

COUT = 10µF

Ratings and

Characteristic Curves (TA= 25°C unless otherwise noted)

GS1085

Vishay Siliconix

www.vishay.com Document Number 74821

407-Mar-05

Ratings and

Characteristic Curves (TA= 25°C unless otherwise noted)

--0.1

2.5A

0.1A

--0.05

0.05

0.1

40 80 120 160 200

Fig. 7 – Load Transient Response

Load Current

Output Voltage

(V, AC)

Time (µs)

VIN = 5V

CIN = 1µF

COUT = 10µF (Tantalum)

VOUT = 3.3V --100

7.0

6.0

--50

10 20 30 40 50

Fig. 8 – Line Transient Response

Input Voltage (V)

Output Voltage

(mV, AC)

Time (µs)

COUT = 10µF (Tantalum)

VOUT = 3.3V

Document Number 74821 www.vishay.com

07-Mar-05 5

GS1085

Vishay Siliconix

PART NUMBER OUTPUT VOLTAGE PACKAGE PACKING AMBIENT TEMP

(V) RANGE

GS1085CE/27F-E3 Adjustable

GS1085CE-18/27F-E3 1.8 TO-252AB Tape/Reel

GS1085CE-25/27F-E3 2.5 2500/Reel

GS1085CE-33/27F-E3 3.3

GS1085CM/31F-E3 Adjustable

GS1085CM-18/31F-E3 1.8 TO-263AB Tape/Reel - 20°C to + 85°C

GS1085CM-25/31F-E3 2.5 800/Reel

GS1085CM-33/31F-E3 3.3

GS1085CT/45F-E3 Adjustable

GS1085CT-18/45F-E3 1.8 TO-220AB Tube

GS1085CT-25/45F-E3 2.5 50/Tube

GS1085CT-33/45F-E3 3.3

Ordering Information

* E3 designates Lead (Pb)-free product

GS1085

Vishay Siliconix

www.vishay.com Document Number 74821

607-Mar-05

9.65

10.29

8.63

9.66

14.60

15.88

123

4.06

4.83

1.14

1.40

0.7 (max.)

2.28

2.80

0.50

1.00

1.14

1.40

2.54 (TYP.)

1.40 (max.)

TO-263

TO-252 (DPAK)

5.59

5.33 10.42

9.40

5.46

5.21

6.73

6.35

0.58

0.46

2.38

2.19

2.28 (TYP.)

0.88

0.64

1.27

1.02

0.51 (min.)

Dimensions in millimeters

10.66

9.66

6.35 Max.

3.42

2.54

4.08

3.54

6.85

5.85

16.51

14.23

14.73

12.70

1.77

1.15

1.01

0.38

2.79

2.29

(with plating)

4.82

3.56 1.39

0.51

1.14

0.31 2.92

2.04

(with plating)

TO-220

Case Outlines