www.fairchildsemi.com TL431/TL431A Programmable Shunt Regulator Features Description • • • • The TL431/TL431A are three-terminal adjustable regulator series with a guaranteed thermal stability over applicable temperature ranges. The output voltage may be set to 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 circuitry provides a very sharp turn-on characteristic, making these devices excel lent replacement for zener diodes in many applications. Programmable Output Voltage to 36 Volts Low Dynamic Output Impedance 0.2Ω 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 1 1.Cathode 2.3.4.5.7.NC 6.Anode 8.Ref 8-SOP 1 1. Cathode 2. 3. 6. 7. Anode 8. Ref 4. 5. NC Rev. 1.0.4 ©2011 Fairchild Semiconductor Corporation TL431/TL431A Internal Block Diagram + - 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 mW TOPR -25 ~ +85 °C TJ 150 °C TSTG -65 ~ +150 °C Reference Input Current Range Power Dissipation D, LP Suffix Package P Suffix Package Operating Temperature Range 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 TL431/TL431A Electrical Characteristics (TA = +25°C, unless otherwise specified) Parameter Reference Input Voltage Symbol Conditions TL431 Min. TL431A Typ. Max. Min. Typ. Max. 2.440 2.495 2.550 2.470 2.495 2.520 Unit VREF VKA=VREF, IKA=10mA Deviation of Reference Input Voltage OverTemperature (Note 1) V ΔVREF/ ΔT VKA=VREF, IKA=10mA TMIN≤TA≤TMAX - 4.5 17 - 4.5 17 Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage ΔVREF/ ΔVKA IKA =10mA ΔVKA=10VVREF - - 1.0 -2.7 - -1.0 -2.7 ΔVKA=36V10V - -0.5 -2.0 - -0.5 -2.0 Reference Input Current IREF IKA=10mA, R1=10KΩ,R2=∞ - 1.5 4 - 1.5 4 μA Deviation of Reference Input Current Over Full Temperature Range ΔIREF/ΔT IKA=10mA, R1=10KΩ,R2=∞ TA =Full Range - 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 mA Off - Stage Cathode Current IKA(OFF) VKA=36V, VREF=0 - 0.05 1.0 - 0.05 1.0 μA Dynamic Impedance (Note 2) ZKA VKA=VREF, IKA=1 to 100mA f ≥1.0KHz - 0.15 0.5 - 0.15 0.5 Ω mV mV/V • TMIN= -25 °C, TMAX= +85 °C 3 TL431/TL431A Test Circuits TL431/A Figure 1. Test Circuit for VKA=VREF TL431/A Figure 3. Test Circuit for lKA(OFF) 4 TL431/A Figure 2. Test Circuit for VKA≥VREF TL431/TL431A 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 TL431/TL431A Typical Application R1 V O = V ref ⎛⎝ 1 + -------⎞⎠ R2 R1 V O = ⎛⎝ 1 + -------⎞⎠ V ref R2 R1 V O = ⎛⎝ 1 + -------⎞⎠ V ref R2 MC7805/LM7805 TL431/A TL431/A TL431/A Figure 10. Shunt Regulator Figure 11. Output Control for ThreeTermianl Fixed Regulator TL431/A Figure 13. Current Limit or Current Source 6 Figure 12. High Current Shunt Regulator TL431/A Figure 14. Constant-Current Sink TL431/TL431A 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 TL431/TL431A Mechanical Dimensions (Continued) Package #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° 8 0.010 –0.002 3.30 ±0.30 0.130 ±0.012 0.33 MIN 0.013 TL431/TL431A 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 9 TL431/TL431A Ordering Information Product Number TL431ACLP TL431ACD Output Voltage Tolerance 1% TL431CLP TL431CP Package TO-92 8-SOP TO-92 2% TL431CD Operating Temperature -25 ~ + 85oC 8-DIP 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 2/22/11 0.0m 001 Stock#DS400301 © 2011 Fairchild Semiconductor Corporation