SN431/SNF431 Programmable Voltage Reference ◈ Description The SN431 series are 3-terminal precision shunt regulators that are programmable over a wide voltage range of 2.495V to 36V with ±0.5%, ±1.0% tolerance. The SN431 series have a low dynamic impedance of 0.15Ω. These features make the SN431 series an excellent replacement for zener diodes in numerous applications circuits that require a precision reference voltage. ◈ Features • Programmable output voltage from 2.495V to 36V • Voltage reference tolerance : ±0.5%, ±1.0% • Cathode current capability of 1mA to 100mA ◈ Pin Assignment (Top View) (Top View) (Top View) A A K A R R K R A K PKG : SOT-89 PKG : SOT-23 PKG : SOT-23 Apply Device : SN431xF Apply Device : SN431xS Apply Device : SNF431xS (Marking Side View) (Top View) (Marking Side View) A R NC NC K RA K R A K PKG : SOT-25 PKG : TO-92 PKG : TO-92M Apply Device : SN431xN Apply Device : SN431x Apply Device : SN431xM [ K : Cathode, A: Anode, KSD-I0A013-006 R : Reference ] 1 SN431/SNF431 ◈ Symbol ◈ Functional block diagram Cathode(K) Cathode(K) Reference(R) + – Reference(R) VREF=2.495V Anode(A) Anode(A) ◈ Ordering Information Vref Tolerance ±1% ±0.5% 1) SN431x Pin Connection : PKG Type Device Name Marking TO-92 SN431A SN431A TO-92M SN431AM SN431A SOT-23 SN431AS1) 4GA□3) SOT-23 SNF431AS2) 4KA□3) SOT-25 SN431AN N4A□3) SOT-89 SN431AF SN431A TO-92 SN431B SN431B TO-92M SN431BM SN431B SOT-23 SN431BS1) 4GB□3) SOT-23 SNF431BS2) 4KB□3) SOT-25 SN431BN N4B□3) SOT-89 SN431BF SN431B 1. Cathode, 2. Reference, 3. Anode 2) SNF431x Pin Connection : 1. Reference, 2. Cathode, 3. Anode 3) □ : Year & Week Code KSD-I0A013-006 2 SN431/SNF431 ◈ Absolute maximum ratings Characteristic [Ta=25℃] Symbol Rating Unit VKA 37 V Cathode current IK 150 mA Reference input current Iref 10 mA SOT-23 PD(Note1) 350 SOT-25 PD(Note1) 400 SOT-89 PD(Note1) 500 TO-92 PD(Note2) 625 TO-92M PD(Note2) 400 Junction Temperature TJ 150 ℃ Operating temperature range Topr -40 ~ +85 ℃ Storage temperature range Tstg -55 ~ +150 ℃ Cathode to Anode voltage Power Dissipation mW Note 1 : Mounted on a glass epoxy PCB board (25.4 × 25.4mm).TA=25℃ Note 2 : TA=25℃ ◈ Recommended operating conditions Characteristic Rating Symbol Cathode to Anode voltage Cathode current Unit Min. Max. VKA Vref 36 V IK 1 100 mA ◈ Electrical Characteristics (Ta=25℃, unless otherwise noted.) Characteristic Symbol Condition Min. Typ. Max. SN431B 2.482 SN431A 2.470 2.508 Reference voltage (Fig.1) Vref VKA=Vref, IK=10mA Reference input voltage deviation over temperature (Fig.1, Note1,2) ΔVref VKA=Vref , IK=10mA @ -40˚C ≤ Ta ≤ 85˚C - 7 30 mV IK=10mA Vref≤VKA≤36V - -1.0 -2.7 mV/V Iref IK=10mA, R1=10KΩ, R2=∞ - 1.8 4.0 μΑ ΔIref IK=10mA, R1=10KΩ, R2=∞ @ -40˚C ≤ Ta ≤ 85˚C - 0.4 2.5 μΑ Ratio of delta reference input voltage to delta cathode voltage (Fig.2) Reference current (Fig.2) Reference input current deviation over temperature (Fig.2, Note 1,2) ΔVref ΔVKA 2.495 Unit 2.520 V Minimum cathode current for regulation IK(MIN) VKA=Vref - 0.35 1.0 mΑ Off-state cathode current (Fig.3) IK(off) VKA=36V, Vref=0V - 2.7 1000 nA Dynamic impedance (Fig.1, Note3) ZKA VKA=Vref, f ≤ 1.0KHz 1.0mA ≤ IK ≤ 100mA - 0.15 0.5 Ω KSD-I0A013-006 3 SN431/SNF431 Fig. 2 Test circuit for VKA>Vref Fig. 1 Test circuit for VKA=Vref Input Input VKA IK VKA Fig. 3 Test circuit for IK(off) Input IK(off) IK R1 VKA Iref R2 Vref V KA = V ref × (1 + R1 ) + I ref × R1 R2 Note. 1. Ambient temperature range: TLOW = -40℃, THigh = 85℃ 2. The deviation parameters △Vref and △Iref are defined as the difference between the maximum value and minimum value obtained over the full operating ambient temperature range that applied. ∆Vref = Vref Max – Vref Min ∆Ta = T2 – T1 Ambient Temperature The average temperature coefficient of the reference input voltage, αVref is defined as: ΔV ref × 10 6 ) ppm V ref (T a = 25℃) α V ref ( )= ℃ ΔT a ( Example : △Vref = 30mV and the slope is positive, △Vref @ 25℃ = 2.495V △Ta = 70℃ 0.03 ( ) × 10 6 ppm 2.495 αVref ( )= = 171ppm / ℃ ℃ 70 3. The dynamic impedance ZKA is defined as: Ζ KA = ΔVKA ΔI K When the device is operating with two external resistors, R1 and R2, (refer to Fig.2) the total dynamic impedance of the circuit is given by: Ζ KA ' = Ζ KA × (1 + KSD-I0A013-006 R1 ) R2 4 SN431/SNF431 ◈ Electrical Characteristic Curves Fig.5 Iref vs TA 1.0 VKA=Vref 0.6 IK=10mA 0.4 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 -60 150 125 100 75 50 25 0 -25 -50 -75 -100 -125 -150 -40 -20 0 20 40 60 80 5.0 4.5 IK=10mA 4.0 R1=10KΩ 3.5 R2=∞ 3.0 2.5 2.0 1.5 1.0 0.5 0.0 100 -60 -40 -20 20 40 60 80 Ambient Temperature - TA [℃] Fig.6 IKA vs VKA Fig.7 IKA vs VKA 100 800 VKA=Vref TA=25℃ 700 VKA=Vref 600 TA=25℃ 500 400 300 200 100 0 -100 -200 -2 -1 0 1 2 -1 3 0 3.0 Vref=0V 2.5 2.0 1.5 1.0 0.5 0.0 -60 -40 -20 0 20 40 60 80 100 Delta Reference Voltage - △Vref [mV] 4.0 VKA= 36V 2 3 Fig.9 △Vref vs VKA Fig.8 Ioff vs TA 3.5 1 Cathode Voltage - VKA [V] Cathode Voltage - VKA [V] Off-State Cathode Current - Ioff [nA] 0 Ambient Temperature - TA [℃] Cathode Current - IKA [µA] Cathode Current - IKA [mA] Reference Voltage Change - Vref 0.8 Reference Input Current - Iref [µA] [%] Fig.4 Vref vs TA 0 IK=10mA -5 TA=25℃ -10 -15 -20 -25 0 4 8 12 16 20 24 28 32 36 40 Cathode Voltage - VKA [V] Ambient Temperature - TA [℃] KSD-I0A013-006 5 SN431/SNF431 ◈ Electrical Characteristic Curves Fig.10 AV vs f 60 OUTPUT IK=10mA Voltage Gain - AV [dB] 50 IK TA=25℃ 10kΩ 220Ω 40 10μF 30 10kΩ 20 GND 10 0 1k 10k 100k 1000k 10000k Voltage Gain Test Circuit Frequency - f [Hz] Fig.11 |ZKA| vs f 500Ω Vout 100 Reference Impedance – |ZKA| [Ω] Rs=100Ω IK=10mA IK TA=25℃ 1uF 10 Vin GND 1 ZKA = Vout/Vin x Rs 0.1 1k 10k 100k 1000k 10000k Dynamic Impedance Test Circuit Frequency - f [Hz] KSD-I0A013-006 6 SN431/SNF431 Fig.12 Pulse Response Voltage Swing [V] 220Ω 0.9V/Div Output Pulse Generator f = 100kHz OUTPUT 50Ω GND 5V/Div Input Pulse Response Test Circuit Time [µS] KSD-I0A013-006 7 SN431/SNF431 ◈ Typical Application Vcc Vcc Vout R1 Vout R2 Vout = ( 1+ Vin R1 )Vref R2 Vth=Vref Fig15. Single-Supply Comparator with Temperature-Compensated Threshold Fig14. Shunt Regulator Vcc Vin < Vref -> Vout=Vcc Vin > Vref -> Vout≒2.0V Isink Iout RCL Vcc Rs Iout = Vref / RCL Isink = Vref / RS Fig17. Constant Current Source Fig16. Constant Current Sink Vcc Vout Vcc Vout R1 R1 R2 R2 Vout = ( 1 + R1 )Vref R2 Vin(min) = Vout + Vbe Vout = ( 1+ Vout(min) = Vref + Vbe Fig18. Series Pass Regulator R1 )Vref R2 Fig19. High Currnet Shunt Regulator KSD-I0A013-006 8 SN431/SNF431 ◈ SOT-89 Outline Dimension (unit : mm) ※ Recommend PCB solder land [Unit: mm] KSD-I0A013-006 9 SN431/SNF431 ◈ SOT-23 Outline Dimension (unit : mm) ※ Recommend PCB solder land [Unit: mm] KSD-I0A013-006 10 SN431/SNF431 ◈ SOT-25 Outline Dimension (unit : mm) ※ Recommend PCB solder land [Unit: mm] KSD-I0A013-006 11 SN431/SNF431 ◈ TO-92 Outline Dimension (unit : mm) KSD-I0A013-006 12 SN431/SNF431 ◈ TO-92M Outline Dimension (unit : mm) KSD-I0A013-006 13 SN431/SNF431 The AUK Corp. products are intended for the use as components in general electronic equipment (Office and communication equipment, measuring equipment, home appliance, etc.). Please make sure that you consult with us before you use these AUK Corp. products in equipments which require high quality and / or reliability, and in equipments which could have major impact to the welfare of human life(atomic energy control, airplane, spaceship, transportation, combustion control, all types of safety device, etc.). AUK Corp. cannot accept liability to any damage which may occur in case these AUK Corp. products were used in the mentioned equipments without prior consultation with AUK Corp.. Specifications mentioned in this publication are subject to change without notice. KSD-I0A013-006 14