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 0.2Ω 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 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 Internal Block Diagram CATHODE REFERENCE 2.5 Vref ANODE CATHODE (K) REFERENCE (R) ANODE (A) Rev. 1.0.7 ©2003 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 1000 mW -25 ~ +85 °C Reference Input Current Range Power Dissipation M, Z Suffix Package N Suffix Package Operating Temperature Range LM431xC TOPR LM431xI -40 ~ +85 °C TJ 150 °C TSTG -65 ~ +150 °C Junction Temperature Storage Temperature Range 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 = +25°C, unless otherwise specified) Parameter Symbol Conditions Reference Input Voltage VREF VKA = VREF, IKA =10mA Deviation of Reference Input Voltage OverTemperature ∆VREF/ ∆T VKA=VREF, IKA=10mA TMIN≤TA≤TMAX LM431A LM431B 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 - -0.5 IKA=10mA, R1=10kΩ,R2=∞ - Deviation of Reference Input Current Over Full Temperature Range IKA=10mA, R1=10kΩ,R2=∞ ∆IREF/∆T TA =Full Range - Minimum Cathode Current for Regulation IKA(MIN) VKA=VREF Off - Stage Cathode Current IKA(OFF) ∆VREF/ ∆VKA Reference Input Current IREF Dynamic Impedance 17 - -1.0 -2.7 -2.0 - -0.5 1.5 4 - 0.4 1.2 - 0.45 1.0 VKA=36V, VREF=0 - 0.05 VKA=VREF, IKA=1 to 100mA f ≥1.0kHz - 0.15 IKA =10mA ∆VKA=36V10V ZKA - 4.5 ∆VKA=10VVREF Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage LM431C - Unit V 4.5 17 mV - -1.0 -2.7 -2.0 - -0.5 -2.0 1.5 4 - 1.5 4 µA 0.4 1.2 0.4 1.2 µA - 0.45 1.0 - 0.45 1.0 mA 1.0 - 0.05 1.0 - 0.05 1.0 µA 0.5 - 0.15 0.5 - 0.15 0.5 Ω mV/V - - 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 VKA≥VREF LM431A/LM431B/LM431C Typical Performance Characteristics Figure 4. Cathode Current vs. Cathode Voltage Figure 6. Change In Reference Input Voltage vs. Cathode Voltage Figure 8. Small Signal Voltage Amplification vs. Frequency Figure 5. Cathode Current vs. Cathode Voltage Figure7. Dynamic Impedance Frequency Figure 9. Pulse Response 5 LM431A/LM431B/LM431C Typical Performance Characteristics (Continued) 140 A IK, CATHODE CURRENT(mA) 120 100 A VKA = Vref B VKA = 5.0 V @ IK = 10mA C VKA = 10 V @ IK = 10mA D VKA = 15 V @ IK = 10mA B C o TA = 25 C 80 60 40 D 20 0 100p 1n 10n 100n 1! CL, LOAD CAPACITANCE Figure 10. Stability Boundary Conditions 6 10! LM431A/LM431B/LM431C Typical Application R V O = V ref 1 + ------1- R 2 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 12. Output Control for Three--Te r- minal Fixed Regulator Figure 11. Shunt Regulator LM431A/B/C Figure 14. Current Limit or Current Source Figure 13. High Current Shunt Regulator LM431A/B/C Figure 15. Constant-Current Sink 7 LM431A/LM431B/LM431C Mechanical Dimensions Package Dimensions in millimeters 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] 8 (0.25) +0.10 0.38 –0.05 1.02 ±0.10 3.86MAX 3.60 ±0.20 (R2.29) +0.10 0.38 –0.05 LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package Dimensions in millimeters 8-SOP MIN #5 1.80 MAX 0.071 3.95 ±0.20 0.156 ±0.008 5.72 0.225 0~ 8° +0.10 0.15 -0.05 +0.004 0.006 -0.002 MAX0.10 MAX0.004 6.00 ±0.30 0.236 ±0.012 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 9 LM431A/LM431B/LM431C Mechanical Dimensions (Continued) Package Dimensions in millimeters #5 1.524 ±0.10 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 +0.10 0.25 –0.05 +0.004 0~15° 10 0.010 –0.002 3.30 ±0.30 0.130 ±0.012 0.33 0.013 MIN LM431A/LM431B/LM431C Ordering Information Product Number LM431CCZ LM431CCM LM431BCZ LM431BCM Output Voltage Tolerance 0.5% 1% LM431ACN LM431ACZ LM431CIZ LM431BIZ LM431BIM LM431AIZ LM431AIM Operating Temperature TO-92 8-SOP TO-92 8-SOP -25 ~ +85°C 8-DIP 2% LM431ACM LM431CIM Package TO-92 8-SOP 0.5% 1% 2% TO-92 8-SOP TO-92 8-SOP -40 ~ +85°C TO-92 8-SOP 11 LM431A/LM431B/LM431C 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 8/4/03 0.0m 001 Stock#DSxxxxxxxx 2003 Fairchild Semiconductor Corporation