Shunt Regulator LM431 LM431A LM431B Shunt Regulator General Description • The LM431 Series ICs are three-terminal programmable shunt regulators with guaranteed thermal stability over a full operation range. These monolithic ICs voltage reference operate as a low temperature coefficient Zener which is programmable from Vref to 36V with two external resistors. These devices exhibit a wide operating current range of 1.0 to 100mA with a typical dynamic impedance of 0.15 to 0.22Ω. The characteristics of these references make them excellent replacements for Zener diodes in many applications such as digital voltmeters, power supplies and op amp circuitry The 2.5V reference makes it convenient to obtain a stable reference from 5.0V logic supplies, and since the LM431 series operates as a shunt regulator, it can be used as either a positive or negative voltage reference. TO-92 SOT-23 SOP-8 SOT-23-5 SOT-89 • The output voltage of both types can be set to any value between VREF (2.5V) and the corresponding maximum cathode voltage. . Features Applications • Programmable Precise Output Voltage from 2.5V to 36V • High Stability under Capacitive Load • Low Temperature Deviation • Can be used in either positive or negative Voltage reference • • • • • • • • • Low Dynamic Output Impedance: 0.15 to 0.22Ω Typical Operating Current from 1.0mA to 100mA Low Output Noise Voltage RoHS Compliance TAITRON COMPONENTS INCORPORATED www.taitroncomponents.com Tel: Fax: Charger Voltage Adapter Switching Power Supply Graphic Card Precision Voltage Reference (800)-TAITRON (800)-824-8766 (800)-TAITFAX (800)-824-8329 (661)-257-6060 (661)-257-6415 Rev. A/DX 2007-06-04 Page 1 of 14 Shunt Regulator LM431 Ordering Information Pin Configuration Outline: Z TO-92 Outline: S8 SOP-8 Outline: N SOT-23 Outline: N5 SOT-23-5 Outline: K SOT-89 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 2 of 14 Shunt Regulator LM431 Block Diagram Symbols Absolute Maximum Ratings (Ta=25° C) (Full operating ambient temperature range applies unless otherwise noted.) Symbol Description VKA IKA TJ Cathode Voltage Cathode Current Range (Continuous) Reference Input Current Range (Continuous) Operating Junction Temperature TOPR TSTG Operating Temperature Range Storage Temperature Range IREF PD RthJA Power Dissipation Package Thermal Impedance LM431 -40 ~ 85 LM431A LM431B Unit 36 -100 ~ 150 V mA -0.05 ~ 10 mA 150 °C -40 ~ 125 -65 ~ 150 Z:TO-92 700 770 N:SOT-23 - 370 N5:SOT-23-5 - 370 K: SOT-89 800 770 S8: SOP-8 - 770 Z:TO-92 180 150 N:SOT-23 - 330 N5:SOT-23-5 - 250 K: SOT-89 160 50 S8: SOP-8 - 150 °C °C mW ° C/W Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 3 of 14 Shunt Regulator LM431 Electrical Characteristics (TA=25ºC, unless otherwise specified) Symbol VREF ∆VREF ∆VREF/∆VKA Description Reference Input Voltage Reference Input Voltage Deviation 0-70° C -40-85 °C Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage LM431 LM431A LM431B Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. 2.440 2.495 2.550 2.480 2.500 2.520 2.490 2.500 2.510 - - - - 4.8 8 - 4.5 8 - 7.0 30 - 4.5 10 - 4.5 10 - -1.4 -2.7 - -1.0 -2.7 - -1.0 -2.7 -1.0 -2.0 - -0.5 -2.0 - -0.5 -2.0 Ta=25° C - 1.8 4.0 - 0.7 4.0 - 0.7 4.0 Ta=Topr - - 6.5 - - - - - - Reference Input Current Deviation - 0.8 2.5 - 0.4 1.2 - 0.4 IMIN Min. Cathode Current For Regulation - 0.5 1.0 - 0.4 1.0 - IOFF Off-State Cathode Current - 2.6 1000 - 50 1000 ZKA Dynamic Impedance - 0.22 - - 0.15 0.5 IREF ∆IREF Test Circuit Conditions V Fig.1 VKA=VREF,IKA=10mA mV Fig.1 (Note1) VKA=VREF,IKA=10mA mV/V - Referenc e Input Current Unit Fig.1- Test Circuit for VKA=VREF Fig.2 IKA= 10mA ∆VKA=10V~ VREF ∆VKA=36V~ 10V IKA=10mA, R1=10KΩ, R2=∞ µA Fig.2 1.2 µA Fig.2 IKA=10mA, R1=10KΩ, R2=∞, 0.4 1.0 mA Fig.1 VKA=VREF - 50 1000 nA Fig.3 VKA=36V, VREF=0V - 0.15 0.5 Ω Fig.1 (Note2) VKA=VREF, IKA=1.0~100mA, f≤1.0KHz -40 ~ 85° C Fig.2- Test Circuit for VKA>VREF Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 4 of 14 Shunt Regulator LM431 Fig.3- Test Circuit for IOFF Note1: Note2: Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 5 of 14 Shunt Regulator LM431 Typical Characteristics Curves Fig.5- IK - VKA Cathode Current IK (µA) Cathode Current IK (mA) Fig.4- IK - VKA Cathode Voltage VKA (V) Cathode Voltage VKA (V) Cathode Voltage VKA (V) Fig.7- │ZKA│ - f Dynamic Impedance │ZKA│ (Ω) Change In Reference Input Voltage ∆VREF (nV) Fig.6- ∆VREF - VKA Frequency f (Hz) Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 6 of 14 Shunt Regulator LM431 Fig.9- Pulse Response Voltage Swing (V) Open Loop Voltage Gain GVO (dB) Fig.8- GVO - f Time t (µs) Frequency f (Hz) Reference Impedance (Ω) Fig.10- Dynamic Impedance vs. Frequency Frequency f (Hz) Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 7 of 14 Shunt Regulator LM431 Typical Application Fig.11-Shunt Regulator Fig.12- High Current Shunt Regulator Fig.13- Current Source of Current Limit Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 8 of 14 Shunt Regulator LM431 Typical Application (Continued) Fig.14- Precision 5V 1.5A Regulator Fig.15- PWM Converter with Reference Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 9 of 14 Shunt Regulator LM431 Device Marking Code Circuit LM431 Tolerance SOT-23 (N) SOT-23-5 (N5) SOT-89 (K) Blank 2.20% 3A 3A 3A A 0.80% EA2 E3B E43B B 0.40% EA1 E3A E43A Dimensions in inches (mm) SOP-8 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 10 of 14 Shunt Regulator LM431 TO-92 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 11 of 14 Shunt Regulator LM431 SOT-23 SOT-23-5 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 12 of 14 Shunt Regulator LM431 SOT-89 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 13 of 14 Shunt Regulator LM431 How to contact us: US HEADQUARTERS 28040 WEST HARRISON PARKAWAY, VALENCIA, CA 91355-4162 Tel: (800) TAITRON (800) 824-8766 (661) 257-6060 Fax: (800) TAITFAX (800) 824-8329 (661) 257-6415 Email: [email protected] Http://www.taitroncomponents.com TAITRON COMPONENTS MEXICO, S.A .DE C.V. BOULEVARD CENTRAL 5000 INTERIOR 5 PARQUE INDUSTRIAL ATITALAQUIA, HIDALGO C.P. 42970 MEXICO Tel: +52-55-5560-1519 Fax: +52-55-5560-2190 TAITRON COMPONETS INCORPORATED E REPRESENTAÇÕES DO BRASIL LTDA RUA DOMINGOS DE MORAIS, 2777, 2.ANDAR, SALA 24 SAÚDE - SÃO PAULO-SP 04035-001 BRAZIL Tel: +55-11-5574-7949 Fax: +55-11-5572-0052 TAITRON COMPONETS INCORPORATED, SHANGHAI REPRESENTATIVE OFFICE CROSS REGION PLAZA, 899 LINGLING ROAD, SUITE 18C, SHANGHAI, 200030, CHINA Tel: +86-21-5424-9942 Fax: +86-21-5424-9931 Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 14 of 14