PROGRAMMABLE PRECISION SHUNT REGULATOR FEATURES TL431/A/C TO-92 PKG z Programmable Output Voltage to 40V z Guaranteed 0.5% Reference Voltage Tolerance z Low (0.2Ω Typ.) Dynamic Output Impedance 3 T O P z Cathode Current Range(Continuous) – 100 ~ 150 mA z Equivalent Full Range Temperature Coefficient of 2 1 50PPM/℃ z Temperature Compensated For Operation Over Full Rate Operating Temperature Range z Low Output Noise Voltage z Fast Turn-on Response z TO-92, SOT-89 or SOT-23 3L Package SOT-23 PKG 2 TOP APPLICATION z z z z z z z Shunt Regulator Precision High-Current Series Regulator High-Current Shunt Regulator Crowbar Circuit PWM Converter With Reference Voltage Monitor Precision Current Limiter 1 3 SOT-89 PKG TOP 1 DESCRIPSION The TL431 is a three-terminal adjustable shunt regulator with specified thermal stability over applicable temperature VREF (Approx. 2.5V) and 40V with two external resistors. This device has a typical dynamic output impedance of 0.2Ω. Active output circuitry provides a very sharp turn-on characteristic, making this device excellent replacement for zener diodes in many applications. The TL431 is characterized for operation from -40℃ to +125℃. PIN 1. Reference 2 2. Anode 3 3. Cathode ORDERING INFORMATION Device Package TL431 TO-92(Bulk) TL431TA TO-92(Taping) TL431SF SOT-23 3L TL431F SOT-89 3L * Refer to the page 2 for detailed ordering Information, Absolute Maximum Ratings (Operating temperature range applies unless otherwise specified) CHARACTERISTIC SYMBOL MIN. MAX. UNIT VKA - 42 V IK -100 150 mA IREF -0.05 10 mA TJ -40 150 ℃ Operating Temperature Range TOPR -40 125 ℃ Storage Temperature Range TSTG -65 150 ℃ Cathode Voltage Cathode Current Range(Continuous) Reference Input Current Range Junction Temperature Range Dec. 2010 – Rev.1.5 -1- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C RECOMMENDED OPERATING CONDITIONS CHARACTERISTIC SYMBOL MIN. MAX. UNIT Cathode Voltage VKA VREF 40 V Cathode Current IK 0.5 100 mA Ordering Information VREF Package Tolerance TL431GC TL431GC TL431CTA TL431-C TL431GCTA TL431GC TL431A TL431-A TL431GA TL431GA TL431ATA TL431-A TL431GATA TL431GA TL431 TL431 TL431G TL431G TL431TA TL431 TL431GTA TL431G TL431CSF 431 TL431GCSF 431 TL431ASF 431 TL431GASF 431 TL431SF 431 TL431GSF 431 0.5% TL431CF 431 Reel 1% TL431AF 431 Reel 2% TL431F 431 Reel 1% 0.5% SOT-23 1% 2% SOT-89 Dec. 2010 – Rev.1.5 Supplied As TL431-C 2% 2.495V Package Marking TL431C 0.5% TO-92 Order No. -2- Bulk Tape Bulk Tape Bulk Tape Reel Reel Reel HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C Ordering Information (continued) Dec. 2010 – Rev.1.5 -3- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C PIN CONFIGURATION 2 Marking Side TOP TOP 1 3 1 2 3 1 2 3 TO-92 PKG SOT-23 PKG SOT-89 PKG PIN DESCRIPTION Pin No. TO-92 / SOT-23 / SOT-89 Name Function 1 Reference Reference Voltage 2 Anode Ground 3 Cathode Input Supply Voltage TL431 ELECTRICAL CHARACTERISTICS (TA=25℃, unless otherwise specified) CHARACTERISTIC Reference Input Voltage Deviation of Reference Input Voltage Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage Reference Input Current Deviation of Reference Input Current SYMBOL VREF ΔVREF/ΔT ΔVREF/ΔVKA TEST CONDITION MIN. TYP. MAX. TL431C 2.483 2.495 2.507 TL431A 2.470 2.495 2.520 TL431 2.440 2.495 2.550 8 20 ΔVKA=10V -VREF -1.4 -2.7 ΔVKA=36V-10V -1.0 -2.0 VKA =VREF, IK =10mA VKA = VREF, IK =10mA TA =Full Range IK =10mA UNIT V mV mV/V IREF IKA=10mA, R1=10㏀, R2=∞ 1.8 4.0 uA ΔIREF/ΔT IK =10mA, R1=10㏀, R2=∞ TA =Full Range 0.4 1.2 uA 0.5 mA Minimum Cathode Current for Regulation IK(MIN) VKA= VREF Off-State Cathode Current IK(OFF) VKA=36V, VREF=0 0.17 0.90 uA VKA= VREF, IK =1mA~100mA f ≤ 1kHz 0.27 0.50 Ω Dynamic Impedance Dec. 2010 – Rev.1.5 ZKA -4- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C TEST CIRCUITS < Fig 1. Test circuit for VKA = VREF > < Fig 2. Test circuit for VKA ≥ VREF > < Fig 3. Test circuit for IKA(OFF) > Dec. 2010 – Rev.1.5 -5- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C The deviation parameters ΔVREF/ΔT and ΔIREF/ΔT are defined as the differences between the maximum and minimum values obtained over the recommended temperature range. The average full-range temperature coefficient of the reference voltage, αVREF, is defined as : VI(dev) ) × 10 6 VREF at 25℃ αVREF (ppm/ ℃) = ΔTA ( Where : ΔTA is the recommended operating free-air temperature range of the device. αVREF can be positive or negative, depending on whether minimum VREF or maximum VREF, respectively, occurs at the lower temperature. Example : Maximum VREF=2496mV at 30℃, maximum VREF=2492mV at 0℃, VREF=2495mV at 25℃, ΔTA=70℃ for TL431C. 4mV ) × 10 6 2495mV = ≈ 23ppm/ ℃ 70℃ ( αVREF Because minimum VREF occurs at the lower temperature, the coefficient is positive. Calculating Dynamic Impedance The dynamic impedance is defined as : Z KA = ΔVKA ΔIKA When the device is operating with two external resistors, the total dynamic impedance of the circuit is given by: Z' = ΔV ≈ Z KA (1 + R1/R2 ) ΔI Dec. 2010 – Rev.1.5 -6- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C TYPICAL OPERATING CHARACTERISTICS Reference Voltage vs. Ambient Temperature Pulse Response Cathode Current vs. Cathode Voltage Cathode Current vs. Cathode Voltage AV-Small Signal Voltage Amplification (dB) Small Signal Voltage Amplification vs. Frequency 60 Output IKA = 10mA TA = 25°C 50 15kΩ 40 IKA 232Ω 10µF 30 20 8.25kΩ 10 0 1k 10k 100k 1000k 10000k < Fig 4. TEST Circuit for Voltage Amplification > Frequency, f [Hz] Dec. 2010 – Rev.1.5 -7- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C TYPICAL OPERATING CHARACTERISTICS (continued) Stability Boundary Conditions 100 150Ω 90 R1 IKA-Cathode Current (mA) 80 C 70 CL A B 60 R2 50 STABLE STABLE 40 30 B < Fig 5. TEST Circuit > A 20 D 10 0 0 1 10 100 1000 10000 100000 A VKA = VREF, R1= 0Ω, R2 = ∞ B VKA = 5.0V, R1=10kΩ, R2 = 10kΩ C VKA = 10.0V, R1=10kΩ, R2 = 3.3kΩ D VKA = 15.0V, R1=10kΩ, R2 = 2KΩ CL-Load Capacitance (nF) Dec. 2010 – Rev.1.5 -8- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C APPLICATION INFORMATION 1. Shunt Regulator Note A : R Should provide cathode current 1mA to the TL431 at minimum VI(BATT) 2. Precision High-Current Series Regulator Note A : R Should provide cathode current≥1mA to the TL431 at minimum VI(BATT) 3. Output Control of a Three-Terminal Fixed Regulator Dec. 2010 – Rev.1.5 -9- HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C 4. High-Current Shunt Regulator 5. Precision 5-V 1.5A Regulator 6. Efficient 5-V Precision Regulator NOTE A : RB Should provide cathode current≥1mA to the TL431. Dec. 2010 – Rev.1.5 - 10 - HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C 7. PWM Converter With Reference 8. Voltage Monitor NOTE A : R3 and R4 are selected to provide the desired LED intensity and cathode current ≥1mA to the TL431 at the available VI(BATT). 9. Delay Timer Dec. 2010 – Rev.1.5 - 11 - HTC PROGRAMMABLE PRECISION SHUNT REGULATOR TL431/A/C 10. Precision Current Limiter 11. Precision Constant-Current Sink Dec. 2010 – Rev.1.5 - 12 - HTC