Fairchild Semiconductor FAN1112 Datasheet
www.fairchildsemi.com
FAN1112
1A 1.2V Low Dropout Linear Regulator
Features
• Low dropout voltage
• Load regulation: 0.05% typical
• Trimmed current limit
• On-chip thermal limiting
• Standard SOT-223 and TO-252 packages
• Three-terminal fixed 1.2V
Applications
• Post regulator for switching supplies
• Supply for low-voltage processors
Typical Application
Description
The FAN1112 is a 1.2V low dropout three-terminal
regulator with 1A output current capability. The device has
been optimized for low voltage where transient response and
minimum input voltage are critical.
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.
Unlike PNP type regulators where up to 10% of the output
current is wasted as quiescent current, the quiescent current
of the FAN1112 flows into the load, increasing efficiency.
The FAN1112 regulator is available in the industry-standard
SOT-223 and TO-252 (DPAK) power packages.
FAN1112
V
= 3.3V V
IN
10µF
++
GND
V
OUT
IN
1.2V at 1A
22µF
REV. 1.0.1 9/27/01
°
°
°
PRODUCT SPECIFICATION FAN1112
Pin Assignments
Front View
Tab is V
OUT
Front View
3
IN
Tab is
V
OUT
2
OUT
1
GND
1
23
GND OUT IN
4-Lead Plastic SOT-223
Θ
= 15°C/W*
JC
*With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane., Θ
3-Lead Plastic TO-252
ΘJC = 3°C/W*
can vary from
JA
30°C/W to more than 50°C/W. Other mounting techniques may provide better thermal resistance than 30°C/W.
Absolute Maximum Ratings
Parameter Min. Max. Unit
V
IN
(V
IN
– V
OUT
) * I
OUT
Operating Junction Temperature Range 0 125
Storage Temperature Range -65 150
Lead Temperature (Soldering, 10 sec.) 300
1.2
1.0
0.8
(A)
0.6
OUT
I
0.4
18 V
See Figure 1
C
C
C
0.2
0
068
VIN – V
10 12 14 16 18 2042
OUT
(V)
Figure 1. Absolute Maximum Safe Operating Area
2
REV. 1.0.1 9/27/01
≤
≤
≤
•
≤
•
≤ 1A •
∆
•
•
•
µ
≤
≤ 1A •
µ
≤
•
•
•
°
°
°
°
FAN1112 PRODUCT SPECIFICATION
Electrical Characteristics
Operating Conditions: V
The • denotes specifications which apply over the specified operating temperature range.
Parameter Conditions Min. Typ. Max. Units
Output Voltage
Line Regulation
Load Regulation
3
1,2
1,2
Dropout Voltage
Current Limit (V
GND Pin Current
GND Pin Current Change 3.0V ≤ V
Minimum Load Current 3.0V ≤ V
Quiescent Current V
Ripple Rejection f = 120Hz, C
Thermal Regulation T
Temperature Stability
Long-Term Stability T
RMS Output Noise
(% of V
OUT
)
Thermal Resistance, Junction
to Case
Thermal Shutdown Junction Temperature 155
Thermal Shutdown
Hysteresis
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. Output current must be limited to meet the absolute maximum ratings of the part.
IN
7V, T
= 25°C unless otherwise specified.
J
10mA ≤ I
FAN1112, 3.0V ≤ V
3.0V ≤ V
(V
– V
IN
V
= 1%, I
REF
– V
IN
= 7V
IN
(V
– V
IN
= 25 ° C, 30ms pulse 0.004 0.02 %/W
A
= 125 ° C, 1000hrs. 0.03 1.0 %
A
T
= 25 ° C, 10Hz ≤ f ≤ 10kHz 0.003 %
A
1A
OUT
12V, I
IN
) = 2V, 10mA ≤ I
OUT
= 1A
OUT
) = 2V
OUT
7V, 10mA ≤ I
IN
15V
IN
= 22 µ F Tantalum,
OUT
) = 3V, I
OUT
IN
OUT
OUT
7.2V
= 10mA
OUT
OUT
= 1A
1.140 1.200 1.260 V
SOT-223 15
TO-252 3
0.005 0.2 %
0.05 0.5 %
1.100 1.200 V
1.1 1.5 A
35 120
0.2 5
10 mA
413mA
60 72 dB
0.5 %
C/W
C/W
10
A
A
C
C
REV. 1.0.1 9/27/01
3
Loading...