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FAN1589
2.7A, 1.2V Low Dropout Linear Regulator for VRM8.5
Features
• Fast transient response
• Low dropout voltage at up to 2.7A
• Load regulation: 0.05% typical
• Trimmed current limit
• On-chip thermal limiting
• Standard TO-220, TO-263, TO-263 center cut and
TO-252 (DPAK) packages
Applications
• A GTL+ bus supply for VRM 8.5
• Low voltage logic supply
• Post regulator for switching supply
Typical Application
VIN = 3.3V
10µF
+
FAN1589
V
IN
Description
The FAN1589 is a low dropout three-terminal regulator with
2.7A output current capability. This device has been optimized
for V
bus termination, where transient response and mini-
TT
mum input voltage are critical. The FAN1589 offers fixed
1.2V with 2.7A current capability for a GTL+ bus V
termination.
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 FAN1589 is available in the industry-standard TO-220,
TO-263, TO-263 center cut and TO-252 (DPAK) power
packages.
GND
V
OUT
+
22µF
1.2V at 2.7A
TT
REV. 1.0.3 2/25/02
°
°
°
FAN1589 PRODUCT SPECIFICATION
Pin Assignments
FAN1589T
FRONT VIEW
FAN1589M
FRONT VIEW
Tab is OUT
Tab is OUT
12 3
GND OUT
3-Lead Plastic TO-263
θJC = 3°C/W*
FAN1589MC
FRONT VIEW
12 3
GND
3-Lead Plastic TO-263 Center Cut
θJC = 3°C/W*
IN
Tab is OUT
IN
12 3
GND OUT
3-Lead Plastic TO-220
θJC = 3°C/W
FAN1589D
FRONT VIEW
GND
3-Lead Plastic TO-252
θJC = 3°C/W*
123
OUT
IN
IN
Tab is OUT
*With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane, Θ
can vary from
JA
30°C/W to more than 40°C/W. Other mounting techniques can provide a thermal resistance lower than 30°C/W.
Absolute Maximum Ratings
Parameter Min. Max. Unit
V
IN
Operating Junction Temperature Range 0 125
Storage Temperature Range -65 150
Lead Temperature (Soldering, 10 sec.) 300
2
7V
REV. 1.0.3 2/25/02
C
C
C
≤
≤
•
≤
=
•
≤
•
∆
•
•
) ≤
•
•
•
°
°
°
PRODUCT SPECIFICATION FAN1589
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
Output Voltage 3.3V ≤ V
10mA ≤ I
Line Regulation
Load Regulation
1, 2
1, 2
(V
I
OUT
(V
OUT
– V
IN
10mA ≤ I
Dropout Voltage
Current Limit (V
V
REF
IN
– V
Minimum Load Current 1.5V ≤ (V
Quiescent Current V
IN
= 5V
Ripple Rejection f = 120Hz, C
(V
– V
IN
Thermal Regulation T
= 25 ° C, 30ms pulse 0.004 0.02 %/W
A
Temperature Stability
Long-Term Stability T
RMS Output Noise
(% of V
OUT
)
Thermal Resistance,
Junction to Case
= 125 ° C, 1000 hrs. 0.03 1.0 %
A
T
= 25 ° C, 10Hz ≤ f ≤ 10kHz 0.003 %
A
TO-220 3
TO-263, TO-252 3
Thermal Shutdown 150
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.
7V
IN
2.7A
OUT
+ 1.5V) ≤ V
10mA
) = 3V
OUT
2.7A
OUT
= 1%, I
OUT
IN
OUT
OUT
) = 2V
– V
OUT
OUT
) = 3V, I
7V,
IN
= 2.7A
5.75V
= 22 µ F Tantalum,
= 2.7A
OUT
1.176 1.200 1.224 V
0.005 0.2 %
0.15 1.5 %
1.150 1.300 V
3.1 4 A
10 mA
413mA
60 72 dB
0.5 %
C/W
C/W
C
REV. 1.0.3 2/25/02
3
FAN1589 PRODUCT SPECIFICATION
Typical Performance Characteristics
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
DROPOUT VOLTAGE (V)
0.7
0.6
0.5
T=0°C
T=25°C
0.5 1 1.5
OUTPUT CURRENT (A)
T=125°C
23.02.50
Figure 1. Dropout Voltage vs. Output Current
1.225
1.220
1.215
1.210
1.205
1.200
1.195
1.190
REFERENCE VOLTAGE (V)
1.185
1.180
1.175
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
0.10
∆I = 2.7A
0.05
0
-0.05
-0.10
-0.15
OUTPUT VOLTAGE DEVIATION (%)
-0.20
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 2. Load Regulation vs. Temperature
1.30
V
SET WITH 1% RESISTORS
OUT
1.20
1.10
1.00
REFERENCE VOLTAGE (V)
0.90
0.80
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 3. Reference Voltage vs. Temperature Figure 4. Output Voltage vs. Temperature
5
4
3
2
1
MINIMUM LOAD CURRENT (mA)
0
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
5.0
4.5
4.0
3.5
SHORT-CIRCUIT CURRENT (A)
3.0
-75 -50 -25 0 25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 5. Minimum Load Current vs. Temperature Figure 6. Short-Circuit Current vs. Temperature
4
REV. 1.0.3 2/25/02
PRODUCT SPECIFICATION FAN1589
Typical Performance Characteristics
90
80
70
60
50
40
30
(VIN – V
20
RIPPLE REJECTIONS (dB)
0.5V ≤ V
I
10
OUT
0
10 100 1K 10K 100K
Figure 7. Ripple Rejection vs. Frequency
≤ 3V
OUT)
RIPPLE
= 2.7A
FREQUENCY (Hz)
≤ 2V
(continued)
20
15
10
POWER (W)
5
0
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
Figure 8. Maximum Power Dissipation
REV. 1.0.3 2/25/02
5
FAN1589 PRODUCT SPECIFICATION
Applications Information
General
The FAN1589 is a three-terminal regulator optimized for a
GTL+ V
tected, and offers thermal shutdown to turn off the regulator
when the junction temperature exceeds about 150°C. The
FAN1589 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 a GTL+.
Stability
The FAN1589 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 <1 Ω .
Protection Diodes
In normal operation, the FAN1589 does not require any protection diodes.
A protection diode between the input and output pins is usually not needed. An internal diode between the input and output pins on the FAN1589 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 1000 µ F to 5000 µ F, 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 9. Usually, normal power supply cycling or
system “hot plugging and unplugging” will not generate current large enough to do any damage.
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.
termination applications. It is short-circuit pro-
TT
D1
1N4002
(OPTIONAL)
Load Regulation
It is not possible to provide true remote load sensing because
the FAN1589 is a three-terminal device. 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.
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 10.
R
P
FAN1589
V
IN OUT
IN
GND
Figure 10. Connection for Best Load Regulation
PARASITIC
LINE RESISTANCE
R
L
Thermal Considerations
The FAN1589 protects itself 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 FAN1589 to generate 2.7A @
1.2V ± 2% from a 3.3V source (3.2V to 3.6V).
Assumptions:
•V
= 3.6V worst case
IN
•V
•I
•T
• θ
The power dissipation in this application is:
PD = (VIN – V
From the specification table:
= 1.176V worst case
OUT
= 2.7A continuous
OUT
= 70°C
A
Case-to-Ambient
= 3°C/W (assuming both a heatsink and
a thermally conductive material)
OUT
) * (I
) = (3.6 – 1.18) * (2.7) = 6.53W
OUT
FAN1589
V
IN
C1
10µF
+
IN OUT
GND
+
C2
22µF
V
OUT
TJ = TA + (PD) * (θ
Case-to-Ambient
= 70 + (6.53) * (3 + 3) = 109°C
+ θJC)
The junction temperature is below the maximum rating.
Figure 9. Optional Protection
6
REV. 1.0.3 2/25/02
PRODUCT SPECIFICATION FAN1589
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
V
3.3V
IN
C1
10µF
+
FAN1589
V
IN
U1
GND
V
OUT
+
conductive spacer if the case of the device must be electrically
isolated and include its contribution to the total thermal
Figure 11. Application Circuit (FAN1589)
resistance. The case of the FAN1589 is directly connected to
the output of the device.
Table 1. Bill of Materials for Application Circuit for the FAN1589
Item Quantity Manufacturer Part Number Description
C1 1 Xicon L10V10 10µF, 10V Aluminum
C3 1 Xicon L10V100 100µF, 10V Aluminum
U1 1 Fairchild FAN1589T 2.7A Regulator
C3
100µF
V
OUT
1.2V
REV. 1.0.3 2/25/02 7
FAN1589 PRODUCT SPECIFICATION
Mechanical Dimensions
3-Lead TO-263 Package
Symbol
A .160 .190 4.06 4.83
b .020 .036 0.51 0.91
b2
c2
D
E
e
L .575 .625 14.61 15.88
L1
L2
R
α
Inches
Min. Max. Min. Max.
.049 .051 1.25 1.30
.045 .055 1.14 1.40
.340 .380 8.64 9.65
.380 .405 9.65 10.29
.100 BSC
.090
.017 .019 0.43 0.78
.110
— .055 — 1.40
0° 8° 0° 8°
@PKG/
@HEATSINK
Millimeters
2.54 BSC
2.29 2.79
E
D
L
E-PIN
L2
Notes
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-.
c2
b2
R (2 PLCS)
L1
b
e
-A--B-
A
-C-
8 REV. 1.0.3 2/25/02
PRODUCT SPECIFICATION FAN1589
Mechanical Dimensions (continued)
3-Lead TO-263 Center Cut Package
Symbol
A .160 .190 4.06 4.83
b .020 .036 0.51 0.91
b2
c2
D
E
e
L .575 .625 14.61 15.88
L1
L2
L3
R
α
Inches
Min. Max. Min. Max.
.049 .051 1.25 1.30
.045 .055 1.14 1.40
.340 .380 8.64 9.65
.380 .405 9.65 10.29
.100 BSC
.090
.050
.017 .019 0.43 0.78
.110
— .055 — 1.40
.070
0° 8° 0° 8°
@PKG/
@HEATSINK
Millimeters
2.54 BSC
2.29 2.79
1.27 1.78
E
D
L
E-PIN
L2
Notes
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-.
c2
b2
b
L3
R (2 PLCS)
L1
e
-A--B-
A
-C-
REV. 1.0.3 2/25/02 9
FAN1589 PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
3-Lead TO-220 Package
Symbol
A .140 .190 3.56 4.83
b .015 .040 .38 1.02
b1 .045 1.14
c1 .014 .022 .36 .56
øP .139 .161 3.53 4.09
D .560 .650 14.22 16.51
E
e
e1 .190 .210 4.83 5.33
e3
F
H1 .230 .270 5.94 6.87
J1
L
L1
Q
α
Inches
Min. Max. Min. Max.
.070 1.78
.380 .420 9.65 10.67
.090 .110 2.29 2.79
.045 — 1.14 —
.020 .055 .51 1.40
.080 .115 2.04 2.92
.500 .580 12.70 14.73
.100 .135 2.54 3.43
3° 7° 3° 7°
Millimeters
6.35 BSC.250 BSC
L
e3
b1
Notes
Notes:
1. Dimension c1 apply for lead finish.
H1
Q
e1
J1
e
E
b
L1
E-PIN øP
(5X)
α
c1
A
D
F
10 REV. 1.0.3 2/25/02
PRODUCT SPECIFICATION FAN1589
Mechanical Dimensions (continued)
3-Lead TO-252 Package
Symbol
A .086 .094 2.19 2.39
b .025 .035 0.64 0.89
b2 .030 0.76
b3 .205 5.21
c .018 .024 0.46 0.61
c2 .018 .023 0.46 0.58
D .210 .245 5.33 6.22 1
E .250 .265 6.35 6.73
e
H
L .055 .070 1.40 1.78
L1
L3
L4
Inches
Min. Max. Min. Max.
.045 1.14
.215 5.46
.090 BSC 2.29 BSC
.370 .410 9.40 10.41
.108 REF 2.74 REF
.035 .080 0.89 2.03
.025 .040 0.64 1.02
E
@PKG/
@HEATSINK
b3
Millimeters
L3
Notes
4
1
3
4
Notes:
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.
c2
D
H
e
A
E-PIN
-C-
L4
L1
-B-
L
α = 0° – 10°
-A-
b2
b
REV. 1.0.3 2/25/02 11
FAN1589 PRODUCT SPECIFICATION
Ordering Information
Product Number Package
FAN1589MX TO-263 in tape and reel
FAN1589MCX TO-263 center cut in tape and reel
FAN1589T TO-220
FAN1589DX TO-252 in tape and reel
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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
ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN;
NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
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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.
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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.
2/25/02 0.0m 004
2002 Fairchild Semiconductor Corporation
Stock#DS30001589
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