www.fairchildsemi.com
FAN1086
1.5A Adjustable/Fixed Low Dropout Linear Regulator
Features
Description
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•
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•
•
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The FAN1086 and FAN1086-2.5, -2.85, -3.3 and -5 are low
dropout three-terminal regulators with 1.5A output current
capability. These devices have been optimized for low voltage
where transient response and minimum input voltage are
critical. The 2.85V version is designed specifically to be
used in Active Terminators for SCSI bus.
Low dropout voltage
Load regulation: 0.05% typical
Trimmed current limit
On-chip thermal limiting
Standard SOT-223, TO-263, and TO-252 packages
Three-terminal adjustable or fixed 2.5V, 2.85V, 3.3V, 5V
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 temperatures that would create excessive junction
temperatures.
Applications
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Active SCSI terminators
High efficiency linear regulators
Post regulators for switching supplies
Battery chargers
5V to 3.3V linear regulators
Motherboard clock supplies
Unlike PNP type regulators where up to 10% of the output
current is wasted as quiescent current, the quiescent current
of the FAN1086 flows into the load, increasing efficiency.
The FAN1086 series regulators are available in the industrystandard SOT-223, TO-263, and TO-252 power packages.
Typical Applications
FAN1086
VIN = 3.3V
VIN
+
VOUT
10µF
R1
124Ω
ADJ
1.5V at 1.5A
+
22µF
R2
24.9Ω
VOUT = VREF(1 + R2/R1) + IAdj • R2
FAN1086-2.85
VIN = 5V
+
VIN
VOUT
10µF
2.85V at 1.5A
+
22µF
GND
REV. 1.0.7 11/10/03
FAN1086
PRODUCT SPECIFICATION
Electrical Characteristics
Operating Conditions: VIN ≤ 7V, TJ = 25°C unless otherwise specified.
The • denotes specifications which apply over the specified operating temperature range.
Parameter
Conditions
Min.
Typ.
Max.
Units
•
1.225
(-2%)
1.250
1.275
(+2%)
V
2.450
2.793
3.234
4.900
2.5
2.85
3.3
5.0
2.550
2.907
3.366
5.100
V
V
V
V
Reference Voltage , VREF
1.5V ≤ (VIN - VOUT) ≤ 5.75V,
10mA ≤ IOUT ≤ 1A
Output Voltage
10mA ≤ IOUT ≤ 1A
FAN1086-2.5, 4V ≤ VIN ≤ 7V
FAN1086-2.85, 4.35V ≤ VIN ≤ 7V
FAN1086-3.3, 4.8V ≤ VIN ≤ 7V
FAN1086-5, 6.5V ≤ VIN ≤ 7V
•
•
•
•
(VOUT + 1.5V) ≤ VIN ≤ 7V, IOUT = 10mA
•
0.005
0.2
%
Load Regulation
(VIN – VOUT) = 2V, 10mA ≤ IOUT ≤ 1A
•
0.05
0.5
%
Dropout Voltage
∆VREF = 1%, IOUT = 1.5A
•
1.300
1.500
V
Current Limit
(VIN – VOUT) = 2V
•
3
Line Regulation1,2
1,2
1.6
2.0
A
•
Adjust Pin Current3, IAdj
35
120
µA
0.2
5
µA
Adjust Pin Current Change3
1.5V ≤ (VIN – VOUT) ≤ 5.75,
10mA ≤ IOUT ≤ 1A
•
Minimum Load Current
1.5V ≤ (VIN – VOUT) ≤ 5.75
•
Quiescent Current
VIN = VOUT + 1.25V
•
Ripple Rejection
f = 120Hz, COUT = 22µF Tantalum,
(VIN – VOUT) = 3V, IOUT = 1.5A
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, 1000hrs.
0.03
RMS Output Noise
(% of VOUT)
TA = 25°C, 10Hz ≤ f ≤ 10kHz
0.003
%
Thermal Resistance,
Juncation to Case
SOT-223
15
°C/W
TO-263, TO-252
3
°C/W
Thermal Shutdown
Junction Temperature
155
°C
10
°C
Thermal Shutdown
Hysteresis
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 current. Guaranteed maximum output power will not be available over the full input/output
voltage range.
3. FAN1086 only.
REV. 1.0.7 11/10/03
3
