www.fairchildsemi.com
FAN1117A
1A Adjustable/Fixed Low Dropout Linear Regulator
Features
Description
•
•
•
•
•
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The FAN1117A and FAN1117A-1.8, -2.5, -2.85, -3.3 and -5
are low dropout three-terminal regulators with 1A 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-220, and TO-252 packages
Three-terminal adjustable or fixed 1.8V, 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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•
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Active SCSI terminators
High efficiency linear regulators
Post regulators for switching supplies
Battery chargers
12V to 5V 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 FAN1117A flows into the load, increasing efficiency.
The FAN1117A series regulators are available in the
industry-standard SOT-223, TO-220, and TO-252 (DPAK)
power packages.
Typical Applications
FAN1117A
VIN = 12V
VIN
+
VOUT
9V at 1A
+
10µF
22µF
R1
124Ω
ADJ
R2
768Ω
VOUT = VREF(1 + R2/R1) + IADJ • R2
FAN1117A-5
VIN = 12V
+
VIN
VOUT
10µF
5V at 1A
+
22µF
GND
REV. 1.1.0 11/7/03
FAN1117A
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
Min.
Typ.
Max.
Units
•
1.225
(-2%)
1.250
1.275
(+2%)
V
10mA ≤ IOUT ≤ 1A
FAN1117A-1.8, 3.3V ≤ VIN ≤ 8.8V
FAN1117A-2.5, 4V ≤ VIN ≤ 9.5V
FAN1117A-2.85, 4.35V ≤ VIN ≤ 9.85V
FAN1117A-3.3, 4.8V ≤ VIN ≤ 10.3V
FAN1117A-5, 6.5V ≤ VIN ≤ 12V
•
•
•
•
•
1.764
2.450
2.793
3.234
4.900
1.8
2.5
2.85
3.3
5.0
1.836
2.550
2.907
3.366
5.100
V
V
V
V
V
(VOUT + 1.5V) ≤ VIN ≤ 12V, IOUT = 10mA
•
0.005
0.2
%
(VIN – VOUT) = 2V, 10mA ≤ IOUT ≤ 1A
•
0.05
0.5
%
Dropout Voltage
∆VREF = 1%, IOUT = 1A
•
1.100
1.200
Current Limit
(VIN – VOUT) = 2V
•
Reference
Voltage3
Output Voltage4
Line Regulation1,2
Load
Regulation1,2
Conditions
1.5V ≤ (VIN – VOUT) ≤ 7V,
10mA ≤ IOUT ≤ 1A
1.1
1.5
V
A
•
35
120
µA
1.5V ≤ (VIN – VOUT) ≤ 7V,
10mA ≤ IOUT ≤ 1A
•
0.2
5
µA
Minimum Load Current
1.5V ≤ (VIN – VOUT) ≤ 15V
•
Quiescent Current
VIN = VOUT + 1.25V
•
4
13
Ripple Rejection
f = 120Hz, COUT = 22µF Tantalum,
(VIN – VOUT) = 3V, IOUT = 1A
Thermal Regulation
TA = 25°C, 30ms pulse
Adjust Pin Current3
Adjust Pin Current
Change3,4
60
mA
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, Junction SOT-223
to Case
TO-252, TO-220
15
°C/W
3
°C/W
Thermal Shutdown
155
°C
10
°C
Thermal Shutdown
Hysteresis
Junction Temperature
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 current. Guaranteed maximum output power will not be available over the full input/
output voltage range.
3. FAN1117A only.
4. Output current must be limited to meet the absolute maximum ratings of the part.
REV. 1.1.0 11/7/03
3
