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FAN431/FAN431A/FAN431L
Programmable Shunt Regulator
Features
Description
•
•
•
•
The FAN431/FAN431A/FAN431L are three terminal
output adjustable regulators with thermal stability over
operating temperature range. The output voltage can be set
any value between VREF (approximately 2.5 volts) and 36
volts with two external resistors. These devices have a
typical dynamic output impedance of 0.2Ω. Active output
circuit provides a sharp turn-on characteristic, making these
devices excellent replacement for Zener Diodes in many
applications.
Programmable Output Voltage to 36 Volts
Low Dynamic Output Impedance 0.2Ω Typical
Sink Current Capability of 1.0 to 100mA
Equivalent Full-Range Temperature Coefficient of
50ppm/°C Typical
• Temperature Compensated for Operation Over Full Rated
Operating Temperature Range
• Low Output Noise Voltage
• Fast Turn-on Response
TO-92
1
1. Ref 2. Anode 3. Cathode
Internal Block Diagram
CATHODE
+
REFERENCE
2.5 Vref
ANODE
CATHODE (K)
REFERENCE (R)
ANODE(A)
Rev. 1.0.3
©2011 Fairchild Semiconductor Corporation
FAN431/FAN431A/FAN431L
Electrical Characteristics
(TA = +25°C, unless otherwise specified)
FAN431A
FAN431L
Symbol
Reference
Input Voltage
VREF
VKA=VREF, IKA=10mA
Deviation of
Reference
Input Voltage
OverTemperature
ΔVREF/
ΔT
VKA=VREF, IKA=10mA
TMIN≤TA≤TMAX
-
4.5
17
-
4.5
17
-
4.5
17
ΔVKA=10VVREF
-
-1.0
-2.7
-
-1.0
-2.7
-
-1.0
-2.7
ΔVKA=36V10V
-
-0.5
-2.0
-
-0.5
-2.0
-
-0.5
-2.0
IKA=10mA,
R1=10kΩ,R2=∞
-
1.5
4
-
1.5
4
-
1.5
4
μA
Deviation of
Reference
Input Current
Over Full
Temperature
Range
IKA=10mA,
ΔIREF/ΔT R1=10kΩ,R2=∞
TA =Full Range
-
0.4
1.2
-
0.4
1.2
-
0.4
1.2
μA
Minimum
Cathode
Current for
Regulation
IKA(MIN)
VKA=VREF
-
0.45
1.0
-
0.45
1.0
-
0.45
1.0
mA
Off -Stage
Cathode
Current
IKA(OFF)
VKA=36V, VREF=0
-
0.05
1.0
-
0.05
1.0
-
0.05
1.0
μA
Dynamic
Impedance
ZKA
VKA=VREF,
IKA=1 to 100mA ,f ≥1.0kHz
-
0.15
0.5
-
0.15
0.5
-
0.15
0.5
Ω
Ratio of
Change in
Reference
Input Voltage
to the Change
in Cathode
Voltage
ΔVREF/
ΔVKA
Reference
Input Current
IREF
Conditions
FAN431
Parameter
IKA
=10mA
Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
2.450 2.500 2.550 2.470 2.495 2.520 2.482 2.495 2.508
Unit
V
mV
mV/V
Note1
TMIN = -25°C, TMAX = +85°C
3
