www.fairchildsemi.com
REV. 1.0.3 3/14/02
Pentium is a registered trademark of Intel Corporation.
Features
Fast transient response
Low dropout voltage at up to 3A
Load regulation: 0.05% typical
Trimmed current limit
On-chip thermal limiting
Standard TO-220, TO-263, TO-263 center cut,
and TO-252 packages
Applications
Pentium
Class GTL+ bus supply
Low voltage logic supply
Post regulator for switching supply
12V to 5V linear regulator
3.3V to 1.5V linear regulator
Description
The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are low
dropout three-terminal regulators with 3A output current capa-
bility. These devices have been optimized for low voltage
applications including V
TT
bus termination, where transient
response and minimum input voltage are critical. The
FAN1587A is ideal for low voltage microprocessor applica-
tions requiring a regulated output from 1.5V to 3.6V with an
input supply of 12V or less. The FAN1587A-1.5 offers fixed
1.5V with 3A current capability for GTL+ bus V
TT
termina-
tion. The FAN1587A-3.3 offers fixed 3.3V current capability
for logic IC operation.
Current limit is trimmed to ensure specified output current and
controlled short-circuit current. On-chip thermal limiting pro-
vides protection against any combination of overload and
ambient temperature that would create excessive junction
temperatures.
The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are
available in the industry-standard TO-220, TO-263, TO-263
center cut, and TO-252 (DPAK) power packages.
Typical Applications
V
IN = 12V
V
OUT =
V
REF
(1+R2/R1)+I
ADJ
*R2
22
F
22
F
22
F
R1
124
R2
768
22
F
9V at 3A
+
+
V
IN
ADJ
V
OUT
FAN1587A
V
IN = 9V
3.3V at 3A
+
+
V
IN
GND
V
OUT
FAN1587A-3.3
65-1587-16
FAN1587A
3A Adjustable/Fixed Low Dropout Linear Regulator
FAN1587A
PRODUCT SPECIFICATION
2
REV. 1.0.3 3/14/02
Pin Assignments
ADJ
*
With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane,
JA
can vary from 30
C/W to more than 40C/W. Other mounting techniques can provide a thermal resistance
lower than 30
C/W.
OUT
FRONT VIEW
3-Lead Plastic TO-220
JC
= 3
C/W
IN
ADJ OUT
FRONT VIEW
3-Lead Plastic TO-263
JC
= 3
C/W*
IN
1
2
3
1
2
3
GND OUT
FRONT VIEW
IN
1
2
3
GND OUT
FRONT VIEW
FAN1587AM
FAN1587AM-1.5
FAN1587AT-1.5, -3.3V
FAN1587AT
IN
1
2
3
ADJ
FRONT VIEW
3-Lead Plastic TO-263 Center Cut
JC
= 3
C/W*
IN
Tab is Out.
1
2
3
GND
FRONT VIEW
FAN1587AMC
FAN1587AMC-1.5, 3.3
IN
1
2
3
ADJ
FRONT VIEW
3-Lead Plastic TO-252
JC
= 3
C/W*
IN
Tab is Out.
Tab is Out.
Tab is Out.
1
2
3
GND
FRONT VIEW
FAN1587AD
FAN1587AD-1.5, 3.3
IN
1
2
3
PRODUCT SPECIFICATION
FAN1587A
REV. 1.0.3 3/14/02
3
Absolute Maximum Ratings
Figure 1. Absolute Maximum Safe Operating Area
Parameter
Min.
Max.
Unit
V
IN
18
V
(V
IN
V
OUT
) * I
OUT
See Figure 1
Operating Junction Temperature Range
0
125
C
Storage Temperature Range
-65
150
C
Lead Temperature (Soldering, 10 sec.)
300
C
V
IN
V
OUT
(V)
I
OUT
(Amps)
0
2
4
6
8
12
10
14
4
3
2
1
0
PRODUCT SPECIFICATION
FAN1587A
REV. 1.0.3 3/14/02
4
Electrical Characteristics
Tj = 25C unless otherwise specified.
The
denotes specifications which apply over the specified operating temperature range.
Notes:
1. 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.
2. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by
input/output differential and the output currrent. Guaranteed maximum output power will not be available over the full input/
output voltage range.
3. FAN1587A only.
4. FAN1587A-1.5 only.
5. FAN1587A-3.3 only.
6. Output current must be limited to meet the absolute maximum ratings of the part.
Parameter
Conditions
Min.
Typ.
Max
Units
Reference Voltage
3
1.5V
(V
IN
V
OUT
)
8.25V,
10mA
I
OUT
3A
1.225
(-2%)
1.250
1.275
(+2%)
V
Output Voltage
4, 6
3.0V
V
IN
8.5V
10mA
I
OUT
3A
1.47
1.5
1.53
V
Output Voltage
5, 6
4.8V
V
IN
10.3V
10mA
I
OUT
3A
3.234
3.3
3.366
V
Line Regulation
1, 2
(V
OUT
+ 1.5V)
V
IN
12V,
I
OUT
=
10mA
0.005
0.2
%
Load Regulation
1, 2
(V
IN
V
OUT
) = 3V
10mA
I
OUT
3A
0.05
0.5
%
Dropout Voltage
V
REF
= 1%, I
OUT
= 3A
1.150
1.300
V
Current Limit
(V
IN
V
OUT
) = 2V
3.1
4
A
Adjust Pin Current
3
35
120
A
Adjust Pin Current
Change
3, 6
1.5V
(V
IN
V
OUT
)
12V,
10mA
I
OUT
3A
0.2
5
A
Minimum Load Current
1.5V
(V
IN
V
OUT
)
12V
10
mA
Quiescent Current
V
IN
= 5V
4
13
mA
Ripple Rejection
f = 120Hz, C
OUT
= 22
F Tantalum,
(V
IN
V
OUT
) = 3V, I
OUT
= 3A
60
72
dB
Thermal Regulation
T
A
= 25
C, 30ms pulse
0.004
0.02
%/W
Temperature Stability
0.5
%
Long-Term Stability
T
A
= 125
C, 1000 hrs.
0.03
1.0
%
RMS Output Noise
(% of V
OUT
)
T
A
= 25
C, 10Hz
f
10kHz
0.003
%
Thermal Resistance,
Junction to Case
TO-220
3
C/W
TO-263, TO-252
3
C/W
Thermal Shutdown
150
C
FAN1587A
PRODUCT SPECIFICATION
5
REV. 1.0.3 3/14/02
Typical Performance Characteristics
Figure 2. Dropout Voltage vs. Output Current
Figure 3. Load Regulation vs. Temperature
Figure 4. Reference Voltage vs. Temperature
Figure 5. Output Voltage vs. Temperature
Figure 6. Minimum Load Current vs. Temperature
Figure 7. Adjust Pin Current vs. Temperature
JUNCTION TEMPERATURE (
C)
OUTPUT VOLTAGE DEVIATION (%)
-75 -50 -25
0
25
50
75 100 125 150 175
0.10
0.05
0
-0.05
-0.10
-0.15
-0.20
I = 3A
65-1587-04
0.5
1
1.5
OUTPUT CURRENT (A)
DROPOUT VOLTAGE (V)
2
3.0
2.5
0
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
T=25
C
T=0
C
T=125
C
65-1587-03
JUNCTION TEMPERATURE (
C)
REFERENCE VOLTAGE (V)
-75 -50 -25
0
25
50
75 100 125 150 175
3.70
3.65
3.60
3.55
3.50
3.45
3.40
3.35
3.30
3.25
3.20
V
OUT
SET WITH 1% RESISTORS
V
OUT
= 3.6V
1
V
OUT
= 3.3V
2
Note:
1. FAN1587A Only
2. FAN1587A, -3.3
65-1587-06
JUNCTION TEMPERATURE (
C)
REFERENCE VOLTAGE (V)
-75 -50 -25
0
25
50
75 100 125 150 175
1.260
1.255
1.250
1.245
1.240
1.235
1.230
1.225
1.220
1.215
1.210
65-1587-05
JUNCTION TEMPERATURE (
C)
MINIMUM LOAD CURRENT (mA)
-75 -50 -25
0
25
50
75 100 125 150 175
5
4
3
2
1
0
65-1587-07
JUNCTION TEMPERATURE (
C)
ADJUST PIN CURRENT (
A)
-75 -50 -25
0
25
50
75 100 125 150 175
100
90
80
70
60
50
40
30
20
10
0
65-1587-08
Note:
1. FAN1587A Only
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