LM431

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 SOT-23-5 SOP-8 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 • 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 Applications • • • • • Charger Voltage Adapter Switching Power Supply Graphic Card Precision Voltage Reference TAITRON COMPONENTS INCORPORATED www.taitroncomponents.com Tel: Fax: (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: N SOT-23 Outline: N5 SOT-23-5 Outline: S8 SOP-8 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 VKA IKA IREF TJ TOPR TSTG Description Cathode Voltage Cathode Current Range (Continuous) Reference Input Current Range (Continuous) Operating Junction Temperature Operating Temperature Range Storage Temperature Range Z:TO-92 N:SOT-23 PD Power Dissipation N5:SOT-23-5 K: SOT-89 S8: SOP-8 Z:TO-92 N:SOT-23 RthJA Package Thermal Impedance N5:SOT-23-5 K: SOT-89 S8: SOP-8 -40 ~ 85 700 800 180 160 LM431 LM431A 36 -100 ~ 150 -0.05 ~ 10 150 -40 ~ 125 -65 ~ 150 770 370 370 770 770 150 330 250 50 150 ° C/W mW LM431B Unit V mA mA °C °C °C 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 Description Reference Input Voltage Reference Input Voltage Deviation 0-70° C LM431 Min. 2.440 Typ. 2.495 Max. 2.550 Min. LM431A Typ. 2.500 Max. 2.520 Min. LM431B Typ. 2.500 Max. 2.510 Unit V Test Circuit Fig.1 Conditions VKA=VREF,IKA=10mA 2.480 2.490 - - - - 4.8 8 - 4.5 8 mV Fig.1 (Note1) VKA=VREF,IKA=10mA ∆VREF -40-85 °C - 7.0 30 - 4.5 10 - 4.5 10 ∆VKA=10V~ VREF ∆VKA=36V~ 10V ∆VREF/∆VKA Ratio of Change in Reference Input Voltage to Change in Cathode to Anode Voltage Ta=25° C Ta=Topr - -1.4 -2.7 - -1.0 -2.7 - -1.0 -2.7 mV/V Fig.2 IKA= 10mA - -1.0 -2.0 - -0.5 -2.0 - -0.5 -2.0 IREF Referenc e Input Current - 1.8 - 4.0 6.5 - 0.7 - 4.0 - - 0.7 - 4.0 µA Fig.2 IKA=10mA, R1=10KΩ, R2=∞ ∆IREF Reference Input Current Deviation - 0.8 2.5 - 0.4 1.2 - 0.4 1.2 µA Fig.2 IKA=10mA, R1=10KΩ, R2=∞, -40 ~ 85° C VKA=VREF IMIN IOFF ZKA Min. Cathode Current For Regulation Off-State Cathode Current Dynamic Impedance - 0.5 1.0 - 0.4 1.0 - 0.4 1.0 mA Fig.1 - 2.6 0.22 1000 - - 50 0.15 1000 0.5 - 50 0.15 1000 0.5 nA Ω Fig.3 Fig.1 (Note2) VKA=36V, VREF=0V VKA=VREF, IKA=1.0~100mA, f≤1.0KHz Fig.1- Test Circuit for VKA=VREF 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.4- IK - VKA Fig.5- IK - VKA Cathode Current IK (mA) Cathode Current IK (µA) Cathode Voltage VKA (V) Cathode Voltage VKA (V) Fig.6- ∆VREF - VKA Fig.7- │ZKA│ - f Cathode Voltage VKA (V) Dynamic Impedance │ZKA│ (Ω) Change In Reference Input Voltage ∆VREF (nV) Frequency f (Hz) Rev. A/DX 2007-06-04 www.taitroncomponents.com Page 6 of 14 Shunt Regulator LM431 Fig.8- GVO - f Open Loop Voltage Gain GVO (dB) Fig.9- Pulse Response Voltage Swing (V) Frequency f (Hz) Time t (µs) Fig.10- Dynamic Impedance vs. Frequency Reference Impedance (Ω) 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 Tolerance Blank LM431 A B 2.20% 0.80% 0.40% SOT-23 (N) 3A EA2 EA1 SOT-23-5 (N5) 3A E3B E3A SOT-89 (K) 3A E43B 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: taitron@taitroncomponents.com 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