FAN1582
3A Adjustable / Fixed Ultra Low Dropout Linear
Regulator
Features
Description
■ Ultra low dropout voltage, 0.4V typical at 3A
The FAN1582, FAN1582-1.5, and FAN1582-2.5 are ultra
low dropout regulators with 3A output current capability.
These devices are optimized for low-voltage applications, including VTT bus termination, where transient
response and minimum input voltage are critical. The
FAN1582 is ideal for low-voltage microprocessor applications requiring a regulated output from 1.3V to 5.7V
with a power input supply of 1.75V to 6.5V.
■ Remote sense operation
■ Fast transient response
■ Load regulation: 0.05% typical
■ 0.5% initial accuracy
■ On-chip thermal limiting
■ 5-pin TO-263 package
The FAN1582-1.5 offers fixed 1.5V with 3A current capabilities for GTL+ bus VTT termination.
Applications
■ Support of GTL+ bus supply
The FAN1582-2.5 offers fixed 2.5V with 3A current capability for logic IC operation and processors while minimizing the overall power dissipation.
■ Low voltage logic supply
■ Embedded processor supplies
■ Split plane regulator
Current limit ensures controlled short-circuit current. Onchip thermal limiting provides protection against combination of overload and ambient temperature that would
create excessive junction temperatures.
■ 2.5V, and 1.8V logic families
■ DDR termination supply
The FAN1582 is available in a 5-pin TO-263 power package.
Ordering Information
Part Number
Package
Pb-Free
Operating
Temperature Range
Packing Method
FAN1582MX
5-Pin TO-263
Yes
-65 to 150°C
Tape and Reel
FAN1582M15X
5-PinTO-263
Yes
-65 to 150°C
Tape and Reel
FAN1582M25X
5-Pin TO-263
Yes
-65 to 150°C
Tape and Reel
VIN = 3.3V
10F
VIN = 3.3V
10F
VCNTL = 5V
+
VIN
VCNTL = 5V
VSENSE
1F
FAN1582
VOUT
+
VIN
VSENSE
FAN1582–2.5
VOUT
VCNTL
2.5V at 3A
+
GND
22F
2.1V at 3A
VCNTL
Adj
+
124
86.6
+
22F
VIN = 5.75V
10F
VCNTL = 12V
+
VIN
VSENSE
FAN1582
VOUT
5V at 3A
VCNTL
Adj
124
+
22F
374
Figure 1. Typical Application
Pentium® is a registered trademark of Intel® corportaion. PowerPC™ is a trademark of IBM Corporation.
© 2003 Fairchild Semiconductor Corporation
FAN1582 Rev. 1.1.4
www.fairchildsemi.com
FAN1582 ⎯ 3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
March 2007
4
VCNTL, Control
5 V , Power
IN
Thermal
Shutdown
Current
Limit
VREF
3 Output
1 Sense
Voltage Loop
Amplifier
2 Adj
Figure 2. Applications Diagram
FRONT VIEW
FRONT VIEW
1 2 3 4 5
1 2 3 4 5
S
GND
OUT
CNTL
IN
S
ADJ
OUT
CNTL
IN
Pin Assignments
5-Lead Plastic TO-263
QJC=3°C/W*
Tab is out.
*With package soldered to 0.5 square inch copper area over backside ground plane or internal
power plane, qJA can vary from 30°C/W to more than 40°C/W. Other mounting techniques
can provide a thermal resistance lower than 30°C/W.
Figure 3. 5-Lead TO-263 Pin Assignments
Pin Definitions
Pin #
Name
Description
1
VSense
Remote Voltage Sense. Connect this pin to the load to permit true remote sensing
and avoid trace drops.
2
ADJ/GND
Adjust or Ground. On the FAN1582, this pin forms the feedback to determine the output voltage. On the FAN1582-1.5 and -2.5, connect this pin to ground.
3
VOUT
Output Voltage. This pin and the tab are output.
4
VCNTL
Control Voltage. This pin draws small signal power to control the FAN1582 circuitry.
Connect to a voltage higher than VIN, as shown in Figure 1.
5
VIN
Input Voltage.
© 2003 Fairchild Semiconductor Corporation
FAN1582 Rev. 1.1.4
www.fairchildsemi.com
2
FAN1582 ⎯ 3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Block Diagram
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The
absolute maximum ratings are stress ratings only.
Symbol
VIN
VCNTL
Parameter
Max.
Input Voltage
Control Voltage
TJ
Operating Junction Temperature Range
TL
Lead Temperature (soldering, 10 seconds)
TSTG
Min.
0
Storage Temperature Range
-65
Unit
7
V
13.2
V
125
°C
300
°C
150
°C
Electrical Characteristics
TJ=25°C, VOUT = VS, VADJ = 0V unless otherwise specified. The • denotes specifications that apply over the specified
operating temperature range.
Symbol
Min.
Typ.
Max.
Units
1.243
1.250
1.257
V
•
1.237
1.250
1.263
V
3V ≤ VIN ≤ 7V (Function of VOUT),
10mA ≤ IOUT ≤ 3A
•
VREF
1.5
5.7
V
Output Voltage(2)
3V ≤ VIN ≤ 7V, 10mA ≤ IOUT ≤ 3A
•
1.47
1.5
1.53
V
Output Voltage (3)
5.1V ≤ VIN ≤ 7V, 10mA ≤ IOUT ≤ 3A
•
2.474
2.5
2.526
V
REG(LINE)
Line Regulation(4)(5)
1.75V ≤ VIN ≤ 5.5V, 2.5V ≤ VCNTL ≤ 12V,
IOUT = 10mA
•
1
3
mV
REG(LOAD)
Load Regulation(4)(5)
VIN = 2.1V, VCNTL = 2.75V,
10mA ≤ IOUT ≤ 3A
•
1
5
mV
Dropout Voltage Minimum
(VCNTL–VOUT)
VIN = 2.05V, ΔVREF = 1%, IOUT = 3A
•
1.05
1.18
V
Dropout Voltage Minimun
(VIN–VOUT)
VCNTL = 2.75V, ΔVREF = 1%,
IOUT = 3A
0.4
0.5
V
Dropout Voltage MinimunVIN
VCNTL = 2.75V, ΔVREF = 1%,
IOUT = 3A
•
0.5
0.6
V
VREF
VADJ
VOUT
VD
IS
Parameter
Condition
Reference Voltage(1)
VIN = 2.0V, VCNTL = 2.75V, IOUT = 10mA
Reference Voltage(1)
2.05V ≤ VIN ≤ 5.5V,
2.7V ≤ VCNTL ≤ 12V,
10mA ≤ IOUT ≤ 3A
Adjustable Output Voltage
Current Limit
VIN = 2.05V, VCNTL = 2.75V
•
ICNTL
Control Pin Current
VIN = 2.05V, VCNTL = 2.75V, IOUT = 10mA
•
3.1
2
6
mA
IADJ
Adjust Pin Current(1)
VIN = 2.05V, VCNTL = 2.75V
•
50
120
µA
IMIN
Minimum Load Current
VIN = 3.3V, VCNTL = 5V
•
5.0
10
mA
RA
Ripple Rejection
VIN = 3.75V, VCNTL = 3.75V,f=120HZ,
COUT = 22µF Tantalum, IOUT = 1.5A
Thermal Resitance
Junction-to-Case
θJC
Thermal Regulation
TA = 25°C, 30ms Pulse
TSD
Thermal Shutdown
60
A
80
dB
3
0.002
150
°C/W
0.02
%/W
°C
Notes:
1. FAN1582 only.
2. FAN1582-1.5 only.
3. FAN1582-2.5 only.
4. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation
are measured at a constant junction temperature by low duty cycle pulse testing.
5. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by input/output differential and the output current. Guaranteed maximum output power is not available over
the full input/output voltage range.
© 2003 Fairchild Semiconductor Corporation
FAN1582 Rev. 1.1.4
www.fairchildsemi.com
3
FAN1582 ⎯ 3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Absolute Maximum Ratings
OUTPUT VOLTAGE DEVIATION (%)
0.8
DROPOUT VOLTAGE (V)
0.7
0.6
0.5
0.4
T=125°C
0.3
T=25°C
T=0°C
0.2
0.1
0.0
0
1
2
4
0.10
ΔΙ=3A
0.05
0
-0.05
-0.10
-0.15
-0.20
-50
-25
OUTPUT CURRENT (A)
Figure 4. Dropout Voltage vs. Output Current
150
2.60
OUTPUT VOLTAGE (V)
REFERENCE VOLTAGE
125
Figure 5. Load Regulation vs. Temperature
1.30
1.28
1.26
1.24
1.22
1.20
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
2.5V
2.35
2.10
1.85
1.60
1.5V
1.35
1.10
-75 -50
Figure 6. Reference Voltage vs. Temperature
-25 0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 9. Output Voltage vs. Temperature
10
70
ADJUST PIN CURRENT (A)
MINIMUM LOAD CURRENT (mA)
0
25
50
75
100
JUNCTION TEMPERATURE (°C)
8
6
4
2
0
60
50
40
30
20
10
0
-75 -50 -25 0
25 50 75 100 125 150 1
JUNCTION TEMPERATURE (°C)
Figure 10. Minimum Load Current vs. Temperature
-25
0
25 50
75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 11. Adjust Pin Current vs. Temperature
© 2003 Fairchild Semiconductor Corporation
FIN1582 Rev. 1.1.4
-75 -50
www.fairchildsemi.com
4
FAN1582 ⎯ 3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Typical Performance Characteristics
11
3.0
SHORT-CIRCUIT CURRENT (A)
CONTROL PIN CURRENT (mA)
3.5
10mA Load
2.5
2.0
1.5
1.0
9
7
5
0.5
3
0
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 12. Control Pin Current vs. Temperature
Figure 13. Short-Circuit Current vs. Temperature
90
20
70
15
POWER (W)
RIPPLE REJECTIONS (dB)
80
60
50
40
10
30
5
(VIN—VOUT) 3V
20
0.5V VRIPPLE 2V
10
IOUT = 5A
0
0
10
100
1K
10K
FREQUENCY (HZ)
25
100K
Figure 14. Ripple Rejection vs. Frequency
45
85
105
65
CASE TEMPERATURE
125
Figure 15. Maximum Power Dissipation
MAX. ACCEPTABLE ESR, OHM
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
1
2
LOAD CURRENT, A
3
Figure 16. Stability
© 2003 Fairchild Semiconductor Corporation
FIN1582 Rev. 1.1.4
www.fairchildsemi.com
5
FAN1582 ⎯ 3A Adjustable/Fixed Ultra Low Dropout Linear Regulator
Typical Performance Characteristics (Continued)
The FAN1582, FAN1582-1.5, and FAN1582-2.5 are
three-terminal regulators optimized for GTL+ VTT termination and logic applications. These devices are short-circuit protected and offer thermal shutdown to turn off the
regulator when the junction temperature exceeds
~150°C. The FAN1582 series provides low dropout voltage and fast transient response. Frequency compensation uses capacitors with low ESR while maintaining
stability. This is critical in addressing the needs of lowvoltage, high-speed microprocessor busses like GTL+.
A protection diode between the input and output pins is
usually not needed. An internal diode between the input
and the output pins on the FAN1582 series can handle
microsecond surge currents of 50A to 100A. Even with
large value output capacitors, it is difficult to obtain those
values of surge currents in normal operation. Only with
large values of output capacitance, such as 1000µF to
5000µF, and with the input pin instantaneously shorted to
ground, can damage occur. Because a crowbar circuit at
the input can generate those levels of current, a diode from
output to input is recommended, as shown in Figure 16.
Usually, normal power supply cycling or system “hot
plugging and unplugging” does not generate current
large enough to cause damage.
VIN and VCNTL Functions
The FAN1582 utilizes a dual-supply approach to maximize efficiency. The collector of the power device is
brought out to the VIN pin to minimize internal power dissipation under high-current loads. VCNTL provides power
for the control circuitry and the drive for the output NPN
transistor. VCNTL should be at least 1.2V higher than the
output voltage. Special care was taken to ensure there
are no supply-sequencing problems. The output voltage
does not turn on until both supplies are operating. If the
control voltage comes up first, the output current is typically limited to about 3.0mA until the power input voltage
comes up. If the power input voltage comes up first, the
output does not turn on until the control voltage comes
up. The output can never come up unregulated.
D1
1N4002
(OPTIONAL)
VOUT
VIN
FAN1582
C1
10F
The FAN1582 can also be used as a single-supply
device with the control and power inputs tied together. In
this mode, the dropout is determined by the minimum
control voltage.
VIN
+
Adj VOUT
R1
+
R2
CADJ
VOUT
C2
22F
D1
1N4002
(OPTIONAL)
Stability
VCNTL
VIN
The FAN1582 series requires an output capacitor as a
part of the frequency compensation. It is recommended to
use a 22µF solid tantalum or a 100µF aluminum electrolytic on the output to ensure stability. The frequency compensation of these devices optimizes the frequency
response with low-ESR capacitors. In general, it is suggested to use capacitors with an ESR of
