www.fairchildsemi.com LM431A/LM431B/LM431C Programmable Shunt Regulator Features Description * * * * The LM431A/LM431B/LM431C 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 0.2 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 TO-92 1 1. Ref 2. Anode 3. Cathode 8-DIP 8-SOP 1 1 1.Cathode 2.3.4.5.7.NC 6.Anode 8.Ref 1.Cathode 2.3.6.7.Anode 4.5.NC 8.Ref SOT-89 SOT-23F 3 1 1 2 1. Ref 2. Anode 3. Cathode 1. Cathode 2. Ref 3. Anode Internal Block Diagram Rev. 1.0.4 (c)2001 Fairchild Semiconductor Corporation LM431A/LM431B/LM431C 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 IREF 0.05~ + 10 mA PD 770 mW Reference Input Current Range Power Dissipation M, Z Suffix Package Operating Temperature Range LM431xC TOPR LM431xI Storage Temperature Range -25 ~ + 85 o -40 ~ + 85 oC C o -65 ~ + 150 TSTG C Recommended Operating Conditions Parameter 2 Symbol Min Typ Max Unit Cathode Voltage VKA VREF - 36 V Cathode Current IKA 1.0 - 100 mA LM431A/LM431B/LM431C Electrical Characteristics (TA = +25C, unless otherwise specified) Parameter Symbol Reference Input Voltage VREF VKA=VREF, IKA=10mA VREF/ T VKA=VREF, IKA=10mA TMINTATMAX VREF/ VKA VKA=10VVREF Deviation of Reference Input Voltage OverTemperature Ratio of Change in Reference Input Voltage Conditions LM431A LM431B LM431C 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 - 10 - 2.7 - - 4.5 17 - 1.0 - 2.7 - - 4.5 17 - 1.0 - 2.7 IKA =10mA to the Change in Cathode Voltage Unit V mV mV/V VKA=36V10V - -0.5 -2.0 - -0.5 -2.0 - -0.5 -2.0 IKA=10mA, R1=10K,R2= - 1.5 4 - 1.5 4 - 1.5 4 A Deviation of Reference Input Current Over Full Temperature Range IKA=10mA, R1=10K,R2= IREF/T TA =Full Range - 0.4 1.2 0.4 1.2 0.4 1.2 A 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 A VKA=VREF, IKA=1 to 100mA f 1.0KHz - 0.15 0.5 - 0.15 0.5 - 0.15 0.5 Reference Input Current Dynamic Impedance IREF ZKA - - Note1 * LM431XC : TMIN= -25 C, TMAX= +85 C * LM431XI : TMIN= -40 C, TMAX= +85 C 3 LM431A/LM431B/LM431C Test Circuits LM431A/B/C LM431A/B/C Figure 1. Test Circuit for VKA=VREF LM431A/B/C Figure 3. Test Circuit for lKA(OFF) 4 Figure 2. Test Circuit for VKAVREF LM431A/LM431B/LM431C Typical Perfomance Characteristics Figure 1. Cathode Current vs. Cathode Voltage Figure 2. Cathode Current vs. Cathode Voltage Figure 3. Change In Reference Input Voltage vs. Cathode Voltage Figure 4. Dynamic Impedance Frequency Figure 5. Small Signal Voltage Amplification vs. Frequency Figure 6. Pulse Response 5 LM431A/LM431B/LM431C Typical Application R V O = V ref 1 + ------1- R2 R V O = 1 + ------1- V ref R 2 R V O = 1 + ------1- V ref R 2 LM7805/MC7805 LM431A/B/C LM431A/B/C LM431A/B/C Figure 10. Shunt Regulator Figure 11. Output Control for ThreeTermianl Fixed Regulator LM431A/B/C Figure 13. Current Limit or Current Source 6 Figure 12. High Current Shunt Regulator LM431A/B/C Figure 14. Constant-Current Sink LM431A/LM431B/LM431C Mechanical Dimensions Package TO-92 +0.25 4.58 0.20 4.58 -0.15 14.47 0.40 0.46 0.10 1.27TYP [1.27 0.20] 1.27TYP [1.27 0.20] +0.10 0.38 -0.05 (0.25) +0.10 0.38 -0.05 1.02 0.10 3.86MAX 3.60 0.20 (R2.29) 7 LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package 8-SOP MIN #5 6.00 0.30 0.236 0.012 8 0~ +0.10 0.15 -0.05 +0.004 0.006 -0.002 MAX0.10 MAX0.004 1.80 MAX 0.071 3.95 0.20 0.156 0.008 5.72 0.225 0.41 0.10 0.016 0.004 #4 1.27 0.050 #8 5.13 MAX 0.202 #1 4.92 0.20 0.194 0.008 ( 0.56 ) 0.022 1.55 0.20 0.061 0.008 0.1~0.25 0.004~0.001 0.50 0.20 0.020 0.008 8 LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package 1.524 0.10 #5 0.060 0.004 #4 0.018 0.004 #8 2.54 0.100 9.60 MAX 0.378 #1 9.20 0.20 0.362 0.008 ( 6.40 0.20 0.252 0.008 0.46 0.10 0.79 ) 0.031 8-DIP 5.08 MAX 0.200 7.62 0.300 3.40 0.20 0.134 0.008 3.30 0.30 0.130 0.012 0.33 0.013 MIN +0.10 0.25 -0.05 +0.004 0~15 0.010 -0.002 9 LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package 1.30 0.10 0.40 0.03 2.40 0.10 0.45~0.60 0.20 MIN SOT-23F 0.03~0.10 0.38 REF 0.40 0.03 +0.05 0.12 -0.023 0.96~1.14 0.97REF 2.90 0.10 0.95 0.03 0.95 0.03 1.90 0.03 10 0.508REF LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package 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 11 LM431A/LM431B/LM431C Ordering Information Product Number Output Voltage Tolerance Package LM431CCZ TO-92 LM431CCM 8-SOP LM431CCML 0.5% SOT-89 LM431CCMF SOT-23F LM431BCZ TO-92 LM431BCM LM431BCML 1% 8-SOP SOT-89 LM431BCMF SOT-23F LM431ACN 8-DIP LM431ACZ TO-92 LM431ACM 2% SOT-89 LM431ACMF SOT-23F LM431CIM LM431BIZ LM431BIM LM431AIZ LM431AIM 0.5% 1% 2% -25 ~ + 85 oC 8-SOP LM431ACML LM431CIZ Operating Temperature TO-92 8-SOP TO-92 8-SOP -40 ~ + 85 oC TO-92 8-SOP 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. 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 THE PRESIDENT 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, and (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 a significant injury of the user. 2. A critical component in 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. www.fairchildsemi.com 6/29/01 0.0m 001 Stock#DSxxxxxxxx 2001 Fairchild Semiconductor Corporation