Document
SMD Type
Adjustable Accurate Reference Source TL431K (KL431K)
IC
■ Features
● The output voltage can be adjusted to 36V
● Low dynamic output impedance, its typical value is 0.2Ω
● Trapping current capability is 1 to 100mA
● Low output noise voltage
● Fast on -state response
CATHODE ANODE ANODE NC
1 2 3 4
8 REF 7 ANODE 6 ANODE 5 NC
NC − No internal connection
■ Absolute Maximum Ratings Ta = 25℃
Parameter Cathode Voltage Cathode Current Range(Continuous) Reference Input Current Range Maximum Power Dissipation Thermal Resistance from Juntion to Ambient Operating Junction Temperature Operating Junction Temperature Range Storage Temperature Range
Symbol VKA IKA Iref PD RθJA Tj Topr Tstg
+0.040.21 -0.02
SOP-8
Rating 37
-100~+150 0.05~+10
400 270 150 0 ~ 70 -65 ~ 150
1.50 0.15
1 CATHODE 2 ANODE 3 ANODE 4 NC
5 NC 6 ANODE 7 ANODE 8 REF
Unit V mA
mW ℃/W
℃
■ Electrical Characteristics Ta = 25℃(unless otherwise specified)
Parameter
Symbol
Test Conditions
Min Typ Max Unit
VKA=VREF,IKA=10mA
2.445
2.545
Reference Input Voltage(Fig.1)
Vref RanK
0.5% 1%
2.482 2.495 2.508 2.47 2.52
V
Deviation of Reference Input Voltage Over Temperature(Fig.1) Tmin=0℃ ,Tmax=+70℃
VKA=VREF,IKA=10mA △Vref/△T
Tmin≤Ta≤Tmax
4.5 17 mV
Ratio Of Change in Reference lnput Voltage to the Change in Cathode Voltage (Fig.2)
△Vref/△VKA IKA=10mA
△VKA=VREF ~ 10V △VKA=10V ~ 36V
-1.0 -2.7 mV/V
-0.5 -2.0
Reference Input Current
Iref IKA=10mA,R1=10 kΩ,R2=∞
1.5 4
Deviation Of Reference Input Current Over Full Temperature Range(Fig.2)
Iref / △T
IKA=10mA,R1=10 kΩ,R2=∞ Ta=full Temperature
uA 0.4 1.2
Minmum Cathode Current for Regulation(Fig.1) IKA(min) VKA=VREF
0.45 1.0 mA
Off-state Cathode Current(Fig.3)
IKA(OFF) VKA=40V, VREF=0
0.05 0.5 uA
Dynamic Impedance
ZKA VKA=VREF, IKA=1 to 100mA,f≤1.0KHz
0.15 0.5 Ω
■ Marking
Marking
431
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SMD Type
Adjustable Accurate Reference Source TL431K (KL431K)
IC
■ Typical Characterisitics
Cathode Current versus Cathode Voltage
150
IK, CATHODE CURRENT (mA)
100
50
0
-50 -100
-2
800
VKA=Vref Ta=25℃
-1 0 1 2
VKA, CATHODE VOLTAGE (V)
3
Cathode Current versus Cathode Voltage
KA KA
IK, CATHODE CURRENT (uA)
600
I400 KA(min)
200
ref
0 -200
-1
2600
012
VKA, CATHODE VOLTAGE (V)
VKA=Vref Ta=25℃
3
Reference Input Voltage versus Ambient Temperature
Test Circuit for VKA=Vref
Vref, REFERENCE INPUT VOLTAGE (mV)
2550
2500
2450
2400
2350 -40
VKA=Vref IK=10mA
-20 0 20 40 60 80
Ta, AMBIENT TEMPERATURE (℃)
100
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SMD Type
Adjustable Accurate Reference Source TL431K (KL431K)
■ Typical Characterisitics
Change in Reference Input Voltage versus Cathode Voltage
0
-4
IK=10mA Ta=25℃
IC
△Vref, REFERENCE INPUT VOLTAGE (mV)
-8
-12
-16
Iref, REFERENCE INPUT CURRENT (uA)
-20 0
5 10 15 20 25 30 35 40
VKA, CATHODE VOLTAGE (V)
Reference Input Current versus Ambient Temperature
3.0
2.5
2.0
1.5
1.0
0.5
0.0 -40
-20
0 20 40 60
Ta, AMBIENT TEMPERATURE (℃)
IK=10mA R1=10KΩ
80 100
Off-State Cathode Current versus Ambient Temperature
40
Test Circuit for VKA=Vref(1+R1/R2)+R1*Iref
Test Circuit for Iref
Ioff, OFF-STATE CATHODE CURRENT (nA)
30
20
10
0 -40
-20 0 20 40 60
Ta, AMBIENT TEMPERATURE (℃)
VKA=36V Vref=0V
80 100
Test Circuit for Ioff
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