www.fairchildsemi.com
FAN1585A
5A Adjustable/Fixed Low Dropout Linear Regulator
Features
Description
•
•
•
•
•
•
The FAN1585A, FAN1585A-1.5, and FAN1585A-1.8 are
low dropout three-terminal regulators with 5A 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 5A
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 5A
Load regulation: 0.05% typical
Trimmed current limit
On-chip thermal limiting
Packages: TO-220, TO-252, TO-263 and TO-263 Centercut
Applications
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•
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AGTL+ bus supply for FC-PGA
Low voltage logic supply
Post regulator for switching supply
3.3V to 1.5V linear regulator
5V to 1.8V 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 FAN1585A series regulators are available in the industrystandard TO-220, TO-252, TO-263 and TO-263 Centercut
power packages.
Typical Applications
FAN1585A
VOUT
VIN
VIN = 3.3V
22µF
+
ADJ
1.5V at 5A
+
R1
124Ω
22µF
R2
24.9Ω
VOUT = VREF(1 + R2/R1) + IAdj • R2
FAN1585A-1.5
VIN
VOUT
VIN = 3.3V
+
22µF
GND
1.5V at 5A
+
22µF
REV. 1.1.6 7/8/05
PRODUCT SPECIFICATION
FAN1585A
Electrical Characteristics
Tj = 25°C unless otherwise specified.
The • denotes specifications which apply over the specified operating temperature range.
Parameter
Conditions
3
Min.
Typ.
Max
Units
Reference Voltage
1.5V ≤ (VIN – VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 5A
•
1.225
(-2%)
1.250
1.275
(+2%)
V
Output Voltage4
3.0V ≤ VIN ≤ 8V
10mA ≤ IOUT ≤ 5A
•
1.47
1.5
1.53
V
Output Voltage5
3.3V ≤ VIN ≤ 8.3V
10mA ≤ IOUT ≤ 5A
•
1.764
1.8
1.836
V
Line Regulation1, 2
(VOUT + 1.5V) ≤ VIN ≤ 12V,
IOUT = 10mA
•
0.005
0.2
%
Load Regulation1, 2, 3
(VIN – VOUT) = 3V,
10mA ≤ IOUT ≤ 5A
•
0.05
0.5
%
Dropout Voltage
∆VREF = 1%, IOUT = 5A
•
1.150
1.300
Current Limit
(VIN – VOUT) = 2V
•
Adjust Pin Current3
Adjust Pin Current
Change3
5.1
5.9
V
A
•
35
120
µA
1.5V ≤ (VIN – VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 5A
•
0.2
5
µA
4
13
Minimum Load Current
1.5V ≤ (VIN – VOUT) ≤ 12V
•
Quiescent Current
VIN = 5V
•
Ripple Rejection
f = 120Hz, COUT = 22µF Tantalum,
(VIN – VOUT) = 3V, IOUT = 5A
Thermal Regulation
TA = 25°C, 30ms pulse
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, TO-252, TO-263, and
TO-263 CC
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.
5. FAN1585A-1.8 only.
REV. 1.1.6 7/8/05
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