The GS1084 is a low dropout three terminal regulator with
5A 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 1.4V 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.
Features
• Dropout Voltage 1.3V at 5A 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
Applications
• Post Regulator for Switching Supply
• Microprocessor Power Supplies
• Constant-Current Regulators
• Motherboard I/O Power Supplies
Functional Block Diagram
V
IN
Current
Amp
Mechanical Data
Case:
TO-220AB, TO-263AB (D
2
PAK),
TO-252 (DPAK)
High temperature soldering guaranteed:
260°C/10 seconds at terminals
V
REF
1.25V
55µA
+
+
GM
--
Thermal
Limit
Current
Limit
V
OUT
Case outlines are on the back page
For
fixed
voltage
device
ADJ
GND
Document Number 74800
07-Mar-05
www.vishay.com
1
GS1084
Vishay Siliconix
Maximum Ratings and Thermal Characteristics
Parameter
Vin Pin to ADJ/GND Pin
Thermal Resistance –
Junction to Case
Operating Junction Temperature Range
Storage Temperature Range
TO-220AB
TO-252
TO-263AB
Symbol
Vin
R
θJC
T
J
T
stg
(2)
(T
A
= 25°C unless otherwise noted)
Value
7
3.0
8.0
3.0
- 20 to +125
- 65 to 150
Unit
V
°C/W
°C
°C
Electrical Characteristics
(1)
Parameter
T
J
= 25°C
, V
IN
= 5V, I
o
= 10mA unless otherwise noted.
Symbol
Test Conditions
T
J
= 25°C
0°C
≤
T
J
≤
125°C
2.75V
≤
V
IN
≤
7V
10mA
≤
I
o
≤
5A
GS1084-1.8
V
IN
= 5V
GS1084-2.5
V
IN
= 5V
GS1084-3.3
V
IN
= 7V
GS1084
0°C
≤
T
J
≤
125°C
2.75V
≤
V
IN
≤
7V
10mA
≤
I
o
≤
5A
2.75V
≤
V
IN
≤
7V
T
J
= 25°C
0°C
≤
T
J
≤
125°C
10mA
≤
I
o
≤
5A
T
J
= 25°C
0°C
≤
T
J
≤
125°C
0°C
≤
T
J
≤
125°C
I
o
= 5A
I
o
= 3A
I
o
= 1A
0°C
≤
T
J
≤
125°C
2.75
≤
Vin
≤
7V
10mA
≤
I
o
≤
5A
0°C
≤
T
J
≤
125°C
2.75
≤
Vin
≤
7V
10mA
≤
I
o
≤
5A
0°C
≤
T
J
≤
125°C
I
o
= 0.5A, 0°C
≤
T
J
≤
125°C
0°C
≤
T
J
≤
125°C
Min
1.225
1.213
Typ
1.250
1.250
Max
1.275
1.288
Unit
Reference Voltage, Adjustable Version
V
REF
V
Output Voltage
V
OUT
1.76
2.45
3.23
0.98V
N
1.8
2.5
3.3
V
N
1.84
2.55
3.37
1.02V
N
V
Line Regulation
REG
line
0.015
0.035
0.1
0.2
1.1
1.0
0.95
5.5
–
6.5
55
0.2
0.2
0.3
0.4
1.3
1.2
1.15
–
120
% V
O
Load Regulation
REG
load
% V
O
Dropout Voltage
V
DROP
V
Output Current
Adjust Pin Current
I
o
I
adj
A
µA
Adjust Pin Current Change
Temperature Stability
Min. Load Current, Adjustable Version
∆I
adj
T
S
I
LMIN
–
–
–
0.2
0.5
5
5
–
10
µA
%V
O
mA
www.vishay.com
2
Document Number 74800
07-Mar-05
GS1084
Vishay Siliconix
Electrical Characteristics
(con’t.)
(1)
Parameter
Quiescent Current
Fixed Voltage Version
RMS Output Noise
Ripple Rejection Ratio
Thermal Regulation
Long Term Stability
Symbol
I
Q
N
RR
R
TH
T
J
= 25°C
(2)
, V
IN
= 5V, I
o
= 10mA unless otherwise noted.
Test Conditions
0°C
≤
T
J
≤
125°C
10H
Z
≤
f
≤
10 kH
Z
f = 120 H
Z
, C
O
= 25µF
C
adj
= 25µF
T
A
= 25°C, 30ms Pulse
T
A
= 125°C, 1000 Hrs
Min
–
–
60
–
–
Typ
12
0.003
72
0.02
0.3
Max
14
–
–
0.05
–
Unit
mA
%V
O
dB
%/W
%V
O
Notes:
(1) All parameters, except nominal output voltage are specified for the variable voltage version, allowing a wider V
in
Range.
The specified limits also apply for the fixed voltage versions over the allowable input voltage range: GS1084-1.8 (3.2V - 7.0V), GS1084-2.5 (3.9V - 7.0V),
GS1084-3.3 (4.75V - 7.0V).
(2) To maintain the specified junction temperatures, low duty cycle pulse testing is required for most parameters.
Typical Application Circuit
V
IN
5V
3
2
V
IN
5V
3
2
R1
125Ω
1%
R2
205Ω
1%
V
OUT
3.3V
GS1084-1.8
GS1084-2.5
GS1084-3.3
1
V
OUT
GS1084
1
ADJ
V
REF
C1
10µF
+
+
C2
10µF
C1
10µF
+
+
C2
10µF
Fixed Voltage Regulator
Adjustable Voltage Regulator
Notes:
V
REF
= V
OUT
– V
ADJ
= 1.25V (typ.)
V
OUT
= V
REF
x (1+R2/R1) + I
ADJ
x R2
I
ADJ
= 55µA (typ.)
(1) C1 needed if device is far away from filter capacitors
