ETC FAN1587AD

www.fairchildsemi.com
FAN1587A
3A Adjustable/Fixed Low Dropout Linear Regulator
Features
Description
•
•
•
•
•
•
The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are low
dropout three-terminal regulators with 3A output current capability. These devices have been optimized for low voltage
applications including VTT bus termination, where transient
response and minimum input voltage are critical. The
FAN1587A is ideal for low voltage microprocessor applications 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 VTT termination. The FAN1587A-3.3 offers fixed 3.3V current capability
for logic IC operation.
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
Current limit is trimmed to ensure specified output current and
controlled short-circuit current. On-chip thermal limiting provides 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
FAN1587A
VIN
VOUT
VIN = 12V
10µF
+
9V at 3A
+
ADJ
124Ω
22µF
768Ω
FAN1587A-3.3
VIN
VOUT
VIN = 9V
+
10µF
GND
3.3V at 3A
+
22µF
65-1587-16
Pentium is a registered trademark of Intel Corporation.
REV. 1.0.0 10/13/00
FAN1587A
PRODUCT SPECIFICATION
Pin Assignments
FAN1587AM-1.5
FAN1587AM
FRONT VIEW
FRONT VIEW
FAN1587AT
FAN1587AT-1.5, -3.3V
FRONT VIEW
FRONT VIEW
1
1
2
3
1
GND OUT IN
2
2
3
1
2
3
3
ADJ OUT IN
ADJ OUT IN
3-Lead Plastic TO-263
θJC = 3°C/W*
GND OUT IN
3-Lead Plastic TO-220
θJC = 3°C/W
FAN1587AMC-1.5, 3.3
FAN1587AMC
FAN1587AD-1.5, 3.3
FAN1587AD
FRONT VIEW
FRONT VIEW
FRONT VIEW
FRONT VIEW
Tab is Out.
Tab is Out.
1
2
3
1
2
1
IN
ADJ
3
1
IN
ADJ
2
3
3
GND
GND
2
IN
IN
3-Lead Plastic TO-252
θJC = 3°C/W*
3-Lead Plastic TO-263 Center Cut
θJC = 3°C/W*
* θJA can vary from 20°C/W to >40°C/W with various mounting techniques.
2
REV. 1.0.0 10/13/00
PRODUCT SPECIFICATION
FAN1587A
Absolute Maximum Ratings
Parameter
Min.
VIN
(VIN – VOUT) * IOUT
Max.
Unit
13.2
V
See Figure 1
0
125
°C
-65
150
°C
300
°C
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10 sec.)
4
IOUT (A)
3
2
1
0
0
2
4
6
8
10
12
VIN – VOUT (V)
Figure 1. Absolute Maximum Safe Operating Area
REV. 1.0.0 10/13/00
3
PRODUCT SPECIFICATION
FAN1587A
Electrical Characteristics
Tj = 25°C unless otherwise specified.
The • denotes specifications which apply over the specified operating temperature range.
Parameter
Conditions
Min.
Typ.
Max
Units
1.5V ≤ (VIN – VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 3A
•
1.225
(-2%)
1.250
1.275
(+2%)
V
Output Voltage4, 6
3.3V ≤ VIN ≤ 12V
10mA ≤ IOUT ≤ 3A
•
1.47
1.5
1.53
V
Output Voltage5, 6
5.1V ≤ VIN ≤ 12V
10mA ≤ IOUT ≤ 3A
•
3.234
3.3
3.366
V
Line Regulation1, 2
(VOUT + 1.5V) ≤ VIN ≤ 12V,
IOUT = 10mA
•
0.005
0.2
%
Load Regulation1, 2
(VIN – VOUT) = 3V
10mA ≤ IOUT ≤ 3A
•
0.05
0.5
%
Dropout Voltage
∆VREF = 1%, IOUT = 3A
•
1.150
1.300
Current Limit
(VIN – VOUT) = 2V
•
Reference
Voltage3
3.1
4
V
A
•
35
120
µA
1.5V ≤ (VIN – VOUT) ≤ 12V,
10mA ≤ IOUT ≤ 3A
•
0.2
5
µA
Minimum Load Current
1.5V ≤ (VIN – VOUT) ≤ 12V
•
Quiescent Current
VIN = 5V
•
4
13
Ripple Rejection
f = 120Hz, COUT = 22µF Tantalum,
(VIN – VOUT) = 3V, IOUT = 3A
Thermal Regulation
TA = 25°C, 30ms pulse
Adjust Pin Current3
Adjust Pin Current
Change3, 6
60
mA
72
0.004
•
Temperature Stability
10
mA
dB
0.02
0.5
%/W
%
Long-Term Stability
TA = 125°C, 1000 hrs.
0.03
RMS Output Noise
(% of VOUT)
TA = 25°C, 10Hz ≤ f ≤ 10kHz
0.003
%
Thermal Resistance,
Junction to Case
TO-220
3
°C/W
3
°C/W
150
°C
Thermal Shutdown
TO-263, TO-252
1.0
%
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.
REV. 1.0.0 10/13/00
4
FAN1587A
PRODUCT SPECIFICATION
Typical Performance Characteristics
0.10
1.2
1.1
T=0°C
0.9
T=125°C
T=25°C
0.8
0.7
0.6
0.5
0
0.5
1
1.5
2
2.5
0.05
0
-0.05
-0.10
-0.15
-0.20
-75 -50 -25
3.0
3.65
1.250
3.60
REFERENCE VOLTAGE (V)
3.70
1.255
1.245
1.240
1.235
1.230
1.225
1.220
1.215
0
25 50 75 100 125 150 175
VOUT SET WITH 1% RESISTORS
VOUT = 3.6V1
3.55
3.50
3.45
3.40
VOUT = 3.3V
3.35
Note:
1. FAN1587A Only
2. FAN1587A, -3.3
3.25
3.20
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 4. Reference Voltage vs. Temperature
Figure 5. Output Voltage vs. Temperature
100
5
Note:
1. FAN1587A Only
3
2
0
-75 -50 -25
65-1587-07
1
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 6. Minimum Load Current vs. Temperature
80
70
60
50
40
30
20
65-1587-08
4
ADJUST PIN CURRENT (µA)
90
MINIMUM LOAD CURRENT (mA)
2
3.30
JUNCTION TEMPERATURE (°C)
5
25 50 75 100 125 150 175
Figure 3. Load Regulation vs. Temperature
1.260
65-1587-05
REFERENCE VOLTAGE (V)
Figure 2. Dropout Voltage vs. Output Current
1.210
-75 -50 -25
0
JUNCTION TEMPERATURE (°C)
OUTPUT CURRENT (A)
65-1587-06
1.0
∆I = 3A
65-1587-04
1.3
65-1587-03
DROPOUT VOLTAGE (V)
1.4
OUTPUT VOLTAGE DEVIATION (%)
1.5
10
0
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 7. Adjust Pin Current vs. Temperature
REV. 1.0.0 10/13/00
PRODUCT SPECIFICATION
FAN1587A
Typical Performance Characteristics (continued)
90
5.0
4.0
3.5
3.0
-75 -50 -25
0
25 50 75 100 125 150 175
70
60
50
40
30
20
10
0
10
(VIN – VOUT) ≤ 3V
0.5V ≤ VRIPPLE ≤ 2V
IOUT = 3A
100
JUNCTION TEMPERATURE (°C)
1K
65-1587-10
RIPPLE REJECTIONS (dB)
4.5
65-1587-09
SHORT-CIRCUIT CURRENT (A)
80
10K
100K
FREQUENCY (Hz)
Figure 8. Short-Circuit Current vs. Temperature
Figure 9. Ripple Rejection vs. Frequency
15
10
65-1587-11
POWER (W)
20
5
0
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
Figure 10. Maximum Power Dissipation
REV. 1.0.0 10/13/00
6
PRODUCT SPECIFICATION
FAN1587A
Applications Information
General
The FAN1587A, FAN1587A-1.5, and FAN1587A-3.3 are
three-terminal regulators optimized for GTL+ VTT termination applications. These devices are short-circuit protected,
and offer thermal shutdown to turn off the regulator when the
junction temperature exceeds about 150°C. The FAN1587A
series provides low dropout voltage and fast transient
response. Frequency compensation uses capacitors with low
ESR while still maintaining stability. This is critical in
addressing the needs of low voltage high speed microprocessor buses like GTL+.
D1
1N4002
(OPTIONAL)
FAN1587A
VIN
IN
+
C1
10µF
OUT
ADJ
+
R1
VOUT
C2
22µF
+
CADJ
R2
Stability
The FAN1587A series require 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. It is recommended to use bypass capacitors
such as a 22µF tantalum or a 100µF aluminum on the adjust
pin of the FAN1587A for low ripple and fast transient
response. When these bypassing capacitors are not used at
the adjust pin, larger values of output capacitors provide
equally good results.
D1
1N4002
(OPTIONAL)
FAN1587A-1.5, -3.3
VIN
C1
10µF
+
IN
OUT
GND
+
VOUT
C2
22µF
65-1587-13
Figure 11. Optional Protection
Protection Diodes
In normal operation, the FAN1587A series does not require
any protection diodes. For the FAN1587A, internal resistors
limit internal current paths on the adjust pin. Therefore, even
with bypass capacitors on the adjust pin, no protection diode
is needed to ensure device safety under shortcircuit conditions.
A protection diode between the input and output pins is usually not needed. An internal diode between the input and output pins on the FAN1587A 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. A
crowbar circuit at the input can generate those levels of current; a diode from output to input is then recommended, as
shown in Figure 11. Usually, normal power supply cycling or
system “hot plugging and unplugging” will not generate
current large enough to do any damage.
The adjust pin can be driven on a transient basis ±7V with
respect to the output, without any device degradation. As
with any IC regulator, exceeding the maximum input-tooutput voltage differential causes the internal transistors to
break down and none of the protection circuitry is then
functional.
REV. 1.0.0 10/13/00
Ripple Rejection
In applications that require improved ripple rejection, a
bypass capacitor from the adjust pin of the FAN1587A to
ground reduces the output ripple by the ratio of VOUT/1.25V.
The impedance of the adjust pin capacitor at the ripple frequency should be less than the value of R1 (typically in the
range of 100Ω to 120Ω) in the feedback divider network in
Figure 11. Therefore, the value of the required adjust pin
capacitor is a function of the input ripple frequency. For
example, if R1 equals 100Ω and the ripple frequency equals
120Hz, the adjust pin capacitor should be 22µF. At 10kHz,
only 0.22µF is needed.
Output Voltage
The FAN1587A regulator develops a 1.25V reference voltage between the output pin and the adjust pin (see Figure
12). Placing a resistor R1 between these two terminals
causes a constant current to flow through R1 and down
through R2 to set the overall output voltage. Normally, this
current is the specified minimum load current of 10mA.
The current out of the adjust pin adds to the current from R1
and is typically 35µA. Its output voltage contribution is
small and only needs consideration when very precise output
voltage setting is required.
7
FAN1587A
PRODUCT SPECIFICATION
FAN1587A
VIN
+
OUT
IN
C1
10µF
ADJ
+
VREF
IADJ
35µA
R1
FAN1587A
VOUT
C2
22µF
VIN
IN
OUT
ADJ
R1*
R2
RL
VOUT = VREF (1 + R2/R1) + IADJ (R2)
65-1587-14
* CONNECT R1 TO CASE
CONNECT R2 TO LOAD
Figure 12. Basic Regulator Circuit
Load Regulation
For fixed voltage devices, negative side sensing is a true
Kelvin connection with the ground pin of the device returned
to the negative side of the load. This is illustrated in
Figure 13.
VIN
R2*
65-1587-15
It is not possible to provide true remote load sensing because
the FAN1587A series are three-terminal devices. Load regulation is limited by the resistance of the wire connecting the
regulators to the load. Load regulation per the data sheet
specification is measured at the bottom of the package.
FAN1587A-1.5, -3.3
OUT
IN
RP
PARASITIC
LINE RESISTANCE
RP
PARASITIC
LINE RESISTANCE
GND
RL
Figure 14. Connection for Best Load Regulation
Thermal Considerations
The FAN1587A series protect themselves under overload
conditions with internal power and thermal limiting circuitry.
However, for normal continuous load conditions, do not
exceed maximum junction temperature ratings. It is important to consider all sources of thermal resistance from junction-to-ambient. These sources include the junction-to-case
resistance, the case-to-heat sink interface resistance, and the
heat sink resistance. Thermal resistance specifications have
been developed to more accurately reflect device temperature and ensure safe operating temperatures.
For example, look at using an FAN1587AT to generate 3A
@ 1.5V ± 2% from a 3.3V source (3.2V to 3.6V).
Assumptions:
65-1587-17
Figure 13. Connection for Best Load Regulation
For adjustable voltage devices, negative side sensing is a true
Kelvin connection with the bottom of the output divider
returned to the negative side of the load. The best load regulation is obtained when the top of resistor divider R1 connects directly to the regulator output and not to the load.
Figure 14 illustrates this point.
•
•
•
•
•
VIN = 3.6V worst case
VOUT = 1.46V worst case
IOUT = 3A continuous
TA = 70°C
θCase-to-Ambient = 3°C/W (assuming both a heatsink and
a thermally conductive material)
The power dissipation in this application is:
PD = (VIN – VOUT) * (IOUT) = (3.6 – 1.46) * (3) = 6.42W
If R1 connects to the load, then the effective resistance
between the regulator and the load would be:
From the specification table:
RP × (1 + R2/R1), RP = Parasitic Line Resistance
TJ = TA + (PD) * (θCase-to-Ambient + θJC)
= 70 + (6.42) * (3 + 3) = 109°C
The connection shown in Figure 14 does not multiply RP by
the divider ratio. As an example, RP is about four milliohms
per foot with 16-gauge wire. This translates to 4mV per foot
at 1A load current. At higher load currents, this drop represents a significant percentage of the overall regulation. It is
important to keep the positive lead between the regulator and
the load as short as possible and to use large wire or PC
board traces.
8
The junction temperature is below the maximum rating.
REV. 1.0.0 10/13/00
FAN1587A
PRODUCT SPECIFICATION
Junction-to-case thermal resistance is specified from the IC
junction to the bottom of the case directly below the die. This
is the lowest resistance path for heat flow. Proper mounting
ensures the best thermal flow from this area of the package to
the heat sink. Use of a thermally conductive material at the
case-to-heat sink interface is recommended. Use a thermally
conductive spacer if the case of the device must be electrically isolated and include its contribution to the total thermal
resistance. The cases of the FAN1587A series are directly
connected to the output of the device.
U1
FAN1587A
VIN
12V
C1
10µF
+
ADJ
+
C2
100µF
VOUT
9V
VOUT
VIN
R1
124Ω
+
C3
100µF
R2
768Ω
65-1587-18
Figure 15. Application Circuit (FAN1587A)
Table 1. Bill of Materials for Application Circuit for the FAN1587A
Item
C1
Quantity
Manufacturer
Part Number
1
Xicon
L16V10
L10V100
Description
10µF, 16V Aluminum
C2, C3
2
Xicon
R1
1
Generic
124Ω, 1%
R2
1
Generic
768Ω, 1%
U1
1
Fairchild
9
FAN1587AT
100µF, 10V Aluminum
3A Regulator
REV. 1.0.0 10/13/00
FAN1587A
PRODUCT SPECIFICATION
Mechanical Dimensions
3-Lead TO-263 Package
Symbol
Inches
Millimeters
Notes
Min.
Max.
Min.
Max.
A
b
b2
c2
D
E
e
.160
.020
.190
.036
4.06
0.51
4.83
0.91
L
L1
L2
R
α
.575
.090
—
.017
0°
.049
.051
.045
.055
.340
.380
.380
.405
.100 BSC
.625
.110
.055
.019
8°
1.25
1.30
1.14
1.40
8.64
9.65
9.65
10.29
2.54 BSC
14.61
2.29
—
0.43
0°
Notes:
1. Dimensions are exclusive of mold flash and metal burrs.
2. Standoff-height is measured from lead tip with ref. to Datum -B-.
3. Foot length is measured with ref. to Datum -A- with lead surface
(at inner R).
4. Dimensiuon exclusive of dambar protrusion or intrusion.
5. Formed leads to be planar with respect to one another at seating
place -C-.
15.88
2.79
1.40
0.78
8°
E
@PKG/
@HEATSINK
L2
c2
D
E-PIN
L
R (2 PLCS)
b2
L1
b
e
-B-
-A-
A
-C-
10
REV. 1.0.0 10/13/00
PRODUCT SPECIFICATION
FAN1587A
Mechanical Dimensions (continued)
3-Lead TO-263 Center Cut Package
Inches
Symbol
Millimeters
Notes
Min.
Max.
Min.
Max.
A
b
b2
c2
D
E
e
.160
.020
.190
.036
4.06
0.51
4.83
0.91
L
L1
L2
.575
.090
—
.050
.017
0°
.049
.051
.045
.055
.340
.380
.380
.405
.100 BSC
L3
R
α
.625
.110
.055
.070
.019
8°
1.25
1.30
1.14
1.40
8.64
9.65
9.65
10.29
2.54 BSC
14.61
2.29
—
1.27
0.43
0°
Notes:
1. Dimensions are exclusive of mold flash and metal burrs.
2. Standoff-height is measured from lead tip with ref. to Datum -B-.
3. Foot length is measured with ref. to Datum -A- with lead surface
(at inner R).
4. Dimensiuon exclusive of dambar protrusion or intrusion.
5. Formed leads to be planar with respect to one another at seating
place -C-.
15.88
2.79
1.40
1.78
0.78
8°
E
@PKG/
@HEATSINK
L2
c2
D
E-PIN
L
R (2 PLCS)
b2
L1
L3
b
e
-B-
-A-
A
-C-
REV. 1.0.0 10/13/00
11
PRODUCT SPECIFICATION
FAN1587A
Mechanical Dimensions (continued)
3-Lead TO-220 Package
Inches
Symbol
Min.
A
b
b1
c1
øP
D
E
e
Millimeters
Max.
Min.
.140
.190
.015
.040
.045
.070
.014
.022
.139
.161
.560
.650
.380
.420
.090
.110
.190
.210
.045
—
.020
.055
.230
.270
.080
.115
.500
.580
.250 BSC
.100
.135
3°
7°
e1
e3
F
H1
J1
L
L1
Q
α
Notes
Max.
3.56
4.83
.38
1.02
1.14
1.78
.36
.56
3.53
4.09
14.22
16.51
9.65
10.67
2.29
2.79
4.83
5.33
1.14
—
.51
1.40
5.94
6.87
2.04
2.92
12.70
14.73
6.35 BSC
2.54
3.43
3°
7°
Notes:
1. Dimension c1 apply for lead finish.
H1
Q
L
e3
b1
e
e1
E
b
L1
E-PIN
øP
α (5X)
c1
A
J1
D
REV. 1.0.0 10/13/00
F
12
FAN1587A
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
3-Lead TO-252 Package
Symbol
Inches
Millimeters
Notes:
Notes
Min.
Max.
Min.
Max.
A
b
b2
b3
c
c2
.086
.025
.030
.205
.018
.018
.094
.035
2.19
0.64
0.76
5.21
0.46
0.46
2.39
0.89
D
E
e
H
5.33
6.22
6.35
6.73
2.29 BSC
9.40
10.41
1.40
1.78
2.74 REF
1
L
L1
.210
.245
.250
.265
.090 BSC
.370
.410
.055
.070
.108 REF
L3
L4
.035
.025
0.89
0.64
4
.045
.215
.024
.023
.080
.040
1.14
5.46
0.61
0.58
2.03
1.02
E
@PKG/
@HEATSINK
b3
4
1
1.
Dimensions are exclusive of mold flash, metal burrs or interlead
protrusion.
2.
Stand off-height is measured from lead tip with ref. to Datum -B-.
3.
Foot length is measured with ref. to Datum -A- with lead surface.
4.
Thermal pad contour optional within dimension b3 and L3.
5.
Formed leads to be planar with respect to one another at seating
place -C-.
6.
Dimensions and tolerances per ASME Y14.5M-1994.
3
L3
c2
D
E-PIN
H
L4
b2
L1
L
b
e
-B-
α = 0° – 10°
-A-
A
-C-
13
REV. 1.0.0 10/13/00
FAN1587A
PRODUCT SPECIFICATION
Ordering Information
Product Number
Package
FAN1587AM
TO-263
FAN1587AMC
TO-263 center cut
FAN1587AT
TO-220
FAN1587AD
TO-252
FAN1587AM-1.5
TO-263
FAN1587AMC-1.5
TO-263 center cut
FAN1587AT-1.5
TO-220
FAN1587AD-1.5
TO-252
FAN1587AM-3.3
TO-263
FAN1587AMC-3.3
TO-263 center cut
FAN1587AT-3.3
TO-220
FAN1587AD-3.3
TO-252
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FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO
ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME
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NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to
result in a significant injury of the user.
2. A critical component in any component of a life support device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
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