July 2006 LM431SA/LM431SB/LM431SC tm Programmable Shunt Regulator Features Description • • • • The LM431SA/LM431SB/LM431SC 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 0.20 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 SOT-89 1 1. Ref 2. Anode 3. Cathode SOT-23F 3 1 2 1. Cathode 2. Ref 3. Anode Internal Block Diagram + - Rev. 1.0.5 ©2006 Fairchild Semiconductor Corporation LM431SA/LM431SB/LM431SC Absolute Maximum Ratings (Operating temperature range applies unless otherwise specified.) Parameter Symbol Value Unit Cathode Voltage VKA 37 V Cathode current Range (Continuous) IKA -100 ~ +150 mA Reference Input Current Range IREF -0.05 ~ +10 mA Thermal Resistance Junction-Air (Note1,2) MF Suffix Package ML Suffix Package RθJA 350 220 °C/W PD 350 560 mW Power Dissipation (Note3,4) MF Suffix Package ML Suffix Package TJ 150 °C Operating Temperature Range TOPR -25 ~ +85 °C Storage Temperature Range TSTG -65 ~ +150 °C Junction Temperature Note: 1. Thermal resistance test board Size: 76.2mm * 114.3mm * 1.6mm (1S0P) JEDEC Standard: JESD51-3, JESD51-7 2. Assume no ambient airflow. 3. TJMAX = 150°C, Ratings apply to ambient temperature at 25°C 4. Power dissipation calculation: PD = (TJ - TA)/RθJA Recommended Operating Conditions Parameter 2 Symbol Min. Typ. Max. Unit Cathode Voltage VKA VREF - 36 V Cathode Current IKA 1.0 - 100 mA LM431SA/LM431SB/LM431SC Electrical Characteristics (TA = +25°C, unless otherwise specified) Parameter Symbol Reference Input Voltage VREF VKA=VREF, IKA=10mA Deviation of Reference Input Voltage OverTemperature ∆VREF/ ∆T VKA=VREF, IKA=10mA TMIN≤TA≤TMAX Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage Conditions ∆VKA=10V- ∆VREF/ ∆VKA IKA =10mA VREF LM431SA LM431SB LM431SC 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 - - 4.5 17 -1.0 -2.7 - - 4.5 17 -1.0 -2.7 - - 4.5 17 -1.0 -2.7 Unit V mV mV/V ∆VKA=36V- - -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, R1=10KΩ,R2=∞ ∆IREF/∆T 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 Reference Input Current 10V IREF - - Note1 TMIN = -25°C, TMAX = +85°C 3 LM431SA/LM431SB/LM431SC Test Circuits LM431S LM431S Figure 1. Test Circuit for VKA=VREF LM431S Figure 3. Test Circuit for lKA(OFF) 4 Figure 2. Test Circuit for VKA≥VREF LM431SA/LM431SB/LM431SC Typical Performance Characteristics 800 150 VKA = VREF o VKA = VREF TA = 25 C o TA = 25 C 600 IKA, CATHODE CURRENT (uA) IK, Cathode Current (mA) 100 50 0 IKA(MIN) 400 200 0 -50 -200 -100 -2 -1 0 1 2 -1 3 0 1 2 3 VKA, CATHODE VOLTAGE (V) VKA, Cathode Voltage (V) Figure 4. Cathode Current vs. Cathode Voltage Figure 5. Cathode Current vs. Cathode Voltage 3.5 0.100 Iref, Reference Input Current (uA) Ioff, Off-State Cathode Current (uA) 3.0 0.075 0.050 0.025 0.000 -50 -25 0 25 50 75 100 2.5 2.0 1.5 1.0 0.5 0.0 -50 125 -25 0 o 25 50 75 100 125 o TA, Ambient Temperature ( C) TA, Ambient Temperature ( C) Figure 6. OFF-State Cathode Current vs. Ambient Temperature Figure7. Reference Input Current vs. Ambient Temperature 6 60 o o TA = 25 C IKA = 10mA 50 TA=25 C 5 4 Voltage Swing (V) Open Loop Voltage Gain (dB) 40 INPUT 30 20 3 OUTPUT 2 10 1 0 0 -10 1k 10k 100k 1M 10M Frequency (Hz) Figure 8. Small Signal Voltage Amplification vs. Frequency 0 4 8 12 16 20 Time (us) Figure 9. Pulse Response 5 LM431SA/LM431SB/LM431SC Typical Performance Characteristics (Continued) 5 140 A VKA = Vref B VKA = 5.0 V @ IK = 10mA IK, CATHODE CURRENT(mA) 120 o TA = 25 C 4 A 100 Current(mA) 80 stable stable 60 40 0 100p 1n 10n 2 1 B 20 3 100n 1ٛ 10ٛ CL, LOAD CAPACITANCE 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Anode-Ref. Voltage(V) Figure 10. Stability Boundary Conditions 5 Current(mA) 4 3 2 1 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Ref.-Cathode Voltage(V) Figure 12. Reference-Cathode Diode Curve 6 Figure 11. Anode-Reference Diode Curve LM431SA/LM431SB/LM431SC Typical Application R1 V O = V ref ⎛⎝ 1 + -------⎞⎠ R2 R1 V O = ⎛ 1 + -------⎞ V ref ⎝ R 2⎠ R1 V O = ⎛ 1 + -------⎞ V ref ⎝ R 2⎠ LM7805/MC7805 LM431S LM431S Figure 13. Shunt Regulator - LM431S Figure 14. Output Control for Figure 15. High Current Shunt Regulator Three-Termianl Fixed Regulator LM431S Figure 16. Current Limit or Current Source LM431S Figure 17. Constant-Current Sink 7 LM431SA/LM431SB/LM431SC Mechanical Dimensions Package Dimensions in millimeters SOT-23F Marking 8 43A 43B 2% tolerance 1% tolerance 43C 0.5% tolerance LM431SA/LM431SB/LM431SC Mechanical Dimensions (Continued) Package Dimensions in millimeters SOT-89 1.50 ±0.20 4.50 ±0.20 (0.40) (1.10) 2.50 ±0.20 C0.2 4.10 ±0.20 (0.50) 1.65 ±0.10 0.50 ±0.10 0.40 ±0.10 0.40 +0.10 –0.05 1.50 TYP 1.50 TYP Marking 43A 2% tolerance 43B 43C 1% tolerance 0.5% tolerance 9 LM431SA/LM431SB/LM431SC Ordering Information Product Number LM431SCCML LM431SCCMF LM431SBCML LM431SBCMF LM431SACML LM431SACMF 10 Output Voltage Tolerance 0.5% 1% 2% Package Operating Temperature SOT-89 SOT-23F SOT-89 SOT-23F SOT-89 SOT-23F -25 ~ +85°C LM431SA/LM431SB/LM431SC TRADEMARKS The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. FACT Quiet Series™ GlobalOptoisolator™ GTO™ HiSeC™ I2C™ i-Lo™ ImpliedDisconnect™ IntelliMAX™ ISOPLANAR™ LittleFET™ MICROCOUPLER™ MicroFET™ MicroPak™ MICROWIRE™ MSX™ MSXPro™ Across the board. Around the world.™ The Power Franchise® Programmable Active Droop™ ACEx™ ActiveArray™ Bottomless™ Build it Now™ CoolFET™ CROSSVOLT™ DOME™ EcoSPARK™ E2CMOS™ EnSigna™ FACT™ FAST® FASTr™ FPS™ FRFET™ OCX™ OCXPro™ OPTOLOGIC® OPTOPLANAR™ PACMAN™ POP™ Power247™ PowerEdge™ PowerSaver™ PowerTrench® QFET® QS™ QT Optoelectronics™ Quiet Series™ RapidConfigure™ RapidConnect™ µSerDes™ ScalarPump™ SILENT SWITCHER® SMART START™ SPM™ Stealth™ SuperFET™ SuperSOT™-3 SuperSOT™-6 SuperSOT™-8 SyncFET™ TCM™ TinyBoost™ TinyBuck™ TinyPWM™ TinyPower™ TinyLogic® TINYOPTO™ TruTranslation™ UHC™ UltraFET® UniFET™ VCX™ Wire™ DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN;NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, or (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. PRODUCT STATUS DEFINITIONS Definition of Terms Datasheet Identification Product Status Definition Advance Information Formative or In Design This datasheet contains the design specifications for product development. Specifications may change in any manner without notice. Preliminary First Production This datasheet contains preliminary data, and supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. Obsolete Not In Production This datasheet contains specifications on a product that has been discontinued by Fairchild semiconductor. The datasheet is printed for reference information only. Rev. I20 www.fairchildsemi.com 7/27/06 0.0m 001 Stock#DSxxxxxxxx © 2006 Fairchild Semiconductor Corporation