ETC FAN1585AM

www.fairchildsemi.com
FAN1585A
5.4A Adjustable/Fixed Low Dropout Linear Regulator
Features
Description
•
•
•
•
•
•
•
The FAN1585A and FAN1585A-1.5 are low dropout threeterminal regulators with 5.4A output current capability.
These devices have been optimized for low voltage applications including VTT bus termination for FC-PGA, where
transient response and minimum input voltage are critical.
The FAN1585A-1.5 offers fixed 1.5V with 5.4A current
capabilities for AGTL+ bus VTT termination for FC-PGA.
The FAN1585A is ideal for low voltage microprocessor
applications requiring a regulated output from 1.5V to 3.6V
with an input supply of 5V or less, or for FC-PGA applications with significant trace resistance.
Fast transient response
Low dropout voltage at up to 5.4A
Higher current replacement for RC1585
Load regulation: 0.05% typical
Trimmed current limit
On-chip thermal limiting
Standard TO-220, TO-263 and TO-263 center cut packages
Applications
• AGTL+ bus supply for FC-PGA
• Low voltage logic supply
• Post regulator for switching supply
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 FAN1585A series regulators are available in the industrystandard TO-220, TO-263 and TO-263 center cut power
packages.
Typical Applications
FAN1585A
VOUT
VIN
VIN = 3.3V
10µF
+
1.5V at 5.4A
+
ADJ
124Ω
22µF
24.9Ω
FAN1585A-1.5
VIN
VOUT
VIN = 3.3V
+
10µF
GND
1.5V at 5.4A
+
22µF
Rev. 1.0.5 7/13/00
FAN1585A
PRODUCT SPECIFICATION
Pin Assignments
FAN1585AM-1.5
FAN1585AM
FRONT VIEW
FRONT VIEW
FAN1585AT
FAN1585AT-1.5
FRONT VIEW
FRONT VIEW
1
1
2
3
GND OUT IN
1
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
FAN1585AMC-1.5
FAN1585AMC
FRONT VIEW
FRONT VIEW
Tab is Out.
1
GND
2
3
1
IN
ADJ
2
3
IN
3-Lead Plastic TO-263 Center Cut
θJA = 3°C/W*
* θJA can vary from 20°C/W to >40°C/W with various mounting techniques.
Absolute Maximum Ratings
Parameter
Min.
Max.
Unit
7
V
0
125
°C
-65
150
°C
300
°C
VIN
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10 sec.)
2
REV. 1.0.5
PRODUCT SPECIFICATION
FAN1585A
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
Reference Voltage
1.5V ≤ (VIN – VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 5.4A
•
1.225
(-2%)
1.250
1.275
(+2%)
V
Output Voltage4
3V ≤ VIN ≤ 7V
10mA ≤ IOUT ≤ 5.4A
•
1.47
1.5
1.53
V
Line Regulation1, 2
(VOUT + 1.5V) ≤ VIN ≤ 7V,
IOUT = 10mA
•
0.005
0.2
%
Load Regulation1, 2, 3
(VIN – VOUT) = 3V,
10mA ≤ IOUT ≤ 5.4A
•
0.05
0.5
%
Dropout Voltage
∆VREF = 1%, IOUT = 5.4A
•
1.150
1.300
V
Current Limit
(VIN – VOUT) = 2V
•
3
5.5
5.9
A
Adjust Pin Current3
•
35
120
µA
Adjust Pin Current Change3 1.5V ≤ (VIN – VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 5.4A
•
0.2
5
µA
Minimum Load Current
1.5V ≤ (VIN – VOUT) ≤ 5.75V
•
Quiescent Current
VIN = 5V
•
Ripple Rejection
f = 120Hz, COUT = 22µF Tantalum,
(VIN – VOUT) = 3V, IOUT = 5.4A
Thermal Regulation
TA = 25°C, 30ms pulse
mA
4
60
13
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
TO-263
3
°C/W
150
°C
Thermal Shutdown
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. 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. FAN1585A only.
4. FAN1585A-1.5 only.
REV. 1.0.5
3
FAN1585A
PRODUCT SPECIFICATION
Typical Performance Characteristics
1.5
0.10
OUTPUT VOLTAGE DEVIATION (%)
DROPOUT VOLTAGE (V)
1.4
1.3
1.2
1.1
1.0
T=0°C
0.9
T=125°C
T=25°C
0.8
0.7
0.6
0.5
0
1
2
3
4
5
0.05
0
-0.05
-0.10
-0.15
-0.20
-75 -50 -25
6
3.70
1.245
3.65
1.240
3.60
VOUT set with 1% Resistors
REFERENCE VOLTAGE (V)
REFERENCE VOLTAGE (V)
25 50 75 100 125 150 175
Figure 2. Load Regulation vs. Temperature
1.250
1.235
1.230
1.225
1.220
1.215
1.210
1
VOUT = 3.6V
3.55
3.50
3.45
3.40
3.35
3.30
1.205
1
VOUT = 3.3V
Note:
1. FAN1585A Only
3.25
1.200
-75 -50 -25
0
3.20
-75 -50 -25
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 3. Reference Voltage vs. Temperature
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 4. Output Voltage vs. Temperature
5
100
Note:
1. FAN1585A Only
90
ADJUST PIN CURRENT (µA)
MINIMUM LOAD CURRENT (mA)
0
JUNCTION TEMPERATURE (°C)
OUTPUT CURRENT (A)
Figure 1. Dropout Voltage vs. Output Current
∆I = 5.4A
4
3
2
1
80
70
60
50
40
30
20
10
0
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 5. Minimum Load Current vs. Temperature
4
0
-75 -50 -25
0
25 50 75 100 125 150 175
JUNCTION TEMPERATURE (°C)
Figure 6. Adjust Pin Current vs. Temperature
REV. 1.0.5
PRODUCT SPECIFICATION
FAN1585A
Typical Performance Characteristics (continued)
8.0
90
RIPPLE REJECTIONS (dB)
SHORT-CIRCUIT CURRENT (A)
80
7.0
6.0
5.0
70
60
50
40
30
20
10
4.0
-75 -50 -25
0
25 50 75 100 125 150 175
(VIN – VOUT) ≤ 3V
0.5V ≤ VRIPPLE ≤ 2V
IOUT = 5.4A
0
10
JUNCTION TEMPERATURE (°C)
100
1K
10K
100K
FREQUENCY (Hz)
Figure 7. Short-Circuit Current vs. Temperature
Figure 8. Ripple Rejection vs. Frequency
POWER (W)
20
15
10
5
0
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
Figure 9. Maximum Power Dissipation
REV. 1.0.5
5
FAN1585A
PRODUCT SPECIFICATION
Applications Information
General
The FAN1585A and FAN1585A-1.5 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 about 150°C. The FAN1585A 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)
FAN1585A
VIN
+
C1
10µF
IN
OUT
ADJ
+
R1
VOUT
C2
22µF
+
CADJ
R2
Stability
The FAN1585A series requires an output capacitor as a part
of the frequency compensation. It is recommended to use a
22µF solid tantalum or a 100 µF 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 <1Ω. It is also recommended to use bypass
capacitors such as a 22µF tantalum or a 100µF aluminum on
the adjust pin of the FAN1585A 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.
Protection Diodes
In normal operation, the FAN1585A series does not require
any protection diodes. For the FAN1585A, 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 short-circuit conditions.
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 FAN1585A 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 10. 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-to-output voltage differential causes the internal transistors to break
down and none of the protection circuitry is then functional.
6
D1
1N4002
(OPTIONAL)
FAN1585A-1.5
VIN
C1
10µF
IN
+
OUT
GND
+
VOUT
C2
22µF
Figure 10. Optional Protection
Ripple Rejection
In applications that require improved ripple rejection, a
bypass capacitor from the adjust pin of the FAN1585A 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 10. 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 FAN1585A regulator develops a 1.25V reference voltage between the output pin and the adjust pin (see Figure
11). 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 a very precise output voltage setting is required.
REV. 1.0.5
PRODUCT SPECIFICATION
FAN1585A
FAN1585A
VIN
OUT
IN
+
C1
10µF
ADJ
+
VREF
IADJ
35µA
R1
FAN1585A
VOUT
VIN
C2
22µF
IN
RP
PARASITIC
LINE RESISTANCE
OUT
ADJ
R1*
R2
RL
VOUT = VREF (1 + R2/R1) + IADJ (R2)
* CONNECT R1 TO CASE
CONNECT R2 TO LOAD
Figure 11. Basic Regulator Circuit
R2*
Load Regulation
It is not possible to provide true remote load sensing because
the FAN1585A 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.
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 12.
FAN1585A-1.5
VIN
IN
RP
PARASITIC
LINE RESISTANCE
OUT
Figure 13. Connection for Best Load Regulation
Thermal Considerations
The FAN1585A 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.
GND
RL
For example, look at using an FAN1585AT to generate 5.4A
@ 1.5V ± 2% from a 3.3V source (3.2V to 3.6V).
Assumptions:
Figure 12. 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 the resistor divider R1 connects directly to the regulator output and not to the load.
Figure 13 illustrates this point.
If R1 connects to the load, then the effective resistance
between the regulator and the load would be:
RP x (1 + R2/R1), RP = Parasitic Line Resistance
The connection shown in Figure 13 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.
REV. 1.0.5
•
•
•
•
•
VIN = 3.6V worst case
VOUT = 1.46V worst case
IOUT = 5.4A continuous
TA = 50°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) * (5.4) = 11.6W
From the specification table:
TJ = TA + (PD) * (θCase-to-Ambient + θJC)
= 50 + (11.6) * (3 + 3) = 120°C
The junction temperature is below the maximum rating.
7
FAN1585A
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 FAN1585A series are directly
connected to the output of the device.
U1
FAN1585A
VIN
3.3V
C1
10µF
+
VOUT
1.5V
VOUT
VIN
R1
124Ω
ADJ
+
+
C3
100µF
R2
24.9Ω
C2
100µF
Figure 14. Application Circuit (FAN1585A)
Table 1. Bill of Materials for Application Circuit for the FAN1585A
Item
Quantity
Manufacturer
Part Number
C1
1
Xicon
L10V10
10µF, 10V Aluminum
C2, C3
2
Xicon
L10V100
100µF, 10V Aluminum
R1
1
Generic
124Ω, 1%
R2
1
Generic
24.9Ω, 1%
U1
1
Fairchild
FAN1585AT
U1
FAN1585A-1.5
VIN
3.3V
VIN
C1
10µF
Description
+
VOUT
1.5V
VOUT
GND
+
5.4A Regulator
C3
100µF
Figure 15. Application Circuit (FAN1585A-1.5)
Table 2. Bill of Materials for Application Circuit for the FAN1585A-1.5
Item
Quantity
Manufacturer
Part Number
C1
1
Xicon
L10V10
10µF, 10V Aluminum
C3
1
Xicon
L10V100
100µF, 10V Aluminum
U1
1
Fairchild
FAN1585AT-1.5
8
Description
5.4A Regulator
REV. 1.0.5
PRODUCT SPECIFICATION
FAN1585A
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-
REV. 1.0.5
9
FAN1585A
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
3-Lead TO-263 Center Cut 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
.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-
10
REV. 1.0.5
PRODUCT SPECIFICATION
FAN1585A
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
.060
.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. 1.0.5
F
11
FAN1585A
PRODUCT SPECIFICATION
Ordering Information
Product Number
Package
FAN1585AM
TO-263
FAN1585AMC
TO-263 Center Cut
FAN1585AT
TO-220
FAN1585AM-1.5
TO-263
FAN1585AMC-1.5
TO-263 Center Cut
FAN1585AT-1.5
TO-220
DISCLAIMER
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.
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, or (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 significant injury to the user.
2. A critical component is 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.
www.fairchildsemi.com
7/13/00 0.0m 001
Stock#DS30001585
 1999 Fairchild Semiconductor Corporation