TL431 LINEAR INTEGRATED CIRCUIT PROGRAMMABLE PRECISION REFERENCE SOP-8 DESCRIPTION The Contek TL431 is a three-terminal adjustable regulator with a guaranteed thermal stability over applicable temperature ranges. The output voltage may be set to any value between Vref(approximately 2.5V) and 36 V with two external resistors. It provides very wide applications, including shunt regulator, series regulator, switching regulator, voltage reference and others. 1 TO-92 1 FEATURES SOT-89 *Programmable output Voltage to 36V. *Low dynamic output impedance 0.2W *Sink current capability of 1.0 to 100mA. *Equivalent full-range temperature coefficient of 50ppm/ C typical for operation over full rated operating temperature range. SOP-8 1: Cathode 2,3,6,7: Anode 8:Ref. 4,5: N.C. TO-92 1: Ref; 2:Anode; 3:Cathode SOT-89 1: Ref; 2:Anode; 3:Cathode BLOCK DIAGRAM Contek CATHODE REFERENCE CATHODE (K) REFERENCE (R) ANODE(A) 2.5V Vref ANODE Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 1 TL431 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS (Operating temperature range applies unless otherwise specified)) PARAMETER SYMBOL VALUE UNIT VKA IKA Iref 37 -100 ~ +150 0.05 ~ +10 V mA mA PD 500 300 350 -20 ~ +85 -65 ~ +150 mW mW Cathode Voltage Cathode Current Range(Continuous) Reference Input Current Range Power Dissipation TO-92 SOP-8 SOT-89 Operating Junction Temperature Storage Temperature Temperature Topr Tstg RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN VKA IKA VREF Cathode Voltage Cathode Current MAX UNIT 36 V mA 10 ELECTRICAL CHARACTERISTICS(Ta=25 PARAMETER TYP C C SYMBOL Reference Input Voltage Vref Deviation of reference Input Voltage Over temperature(note 1) Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage DVref/DT Reference Input Current Deviation of Reference Input Current Over Full Temperature Range Minimum Cathode Current for Regulation Off-State Cathode Current Dynamic Impedance Iref DIref/DT C, unless otherwise specified) TEST CONDITIONS VKA=VREF,IKA=10mA MIN IKA(OFF) ZKA MAX UNIT V 4.5 17 mV -1.0 -2.7 -2.0 mV/V -0.5 1.5 0.4 4 1.2 mA mA 0.45 1.0 mA 0.05 0.15 1.0 0.5 mA W VKA=VREF,IKA=10mA TMIN<=TA<=TMAX VKA=10V~VREF VKA=36V~10V DVref /DVKA IKA=10mA IKA(min) TYP 2.440 2.495 2.550 IKA=10mA,R1=10kW,R2= IKA=10mA,R1=10kW,R2= TA=full Temperature VKA=VREF VKA=36V,V REF=0 VKA=VREF,IKA=1 to 100mA f1.0kHz Note:TMIN=0 C,TMAX=+70 C Remark: Reference voltage of =-1% tolerance is also available per customer s request. Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 2 TL431 LINEAR INTEGRATED CIRCUIT TYPICAL PERFORMANCE CHARACTERISTICS Fig 1 Cathode Current Vs Cathode Voltage Fig 2 Cathode Current Vs Cathode Voltage 800 125 Ta=25 C V KA =V REF Ta=25 C V KA =V REF 600 Cathode Current (mA) Cathode Current (mA) 100 75 50 25 0 -25 400 IKA(min) 200 -50 0 -75 -100 -2 -1 0 1 2 3 -200 -2 -1 Cathode Voltage (V) Fig 3 Change in Reference Input Voltage Vs Cathode voltage 0 -15 -20 -25 -30 0 5 10 15 20 25 30 35 4 3 2 0 40 0 1 2 4 5 6 7 Fig 6 Small Signal Voltage Amplification Vs Frequency 70 2 60 Voltage Amplification (dB) ) Impedance ( 3 Time ( m s) Ta=25 C I KA =0mA to 100mA 10 C 1 Fig 5 Dynamic Impedance Vs Frequency 10 3 5 Cathode Voltage (V) 10 2 6 -35 -40 Ta=25 7 I KA =100mA Ta=25 C -10 1 (V) Fig 4 Pulse Response Input and Output Voltage (V) Change In Reference INput Voltage (mV) -5 0 Cathode Voltage 1 0 Ta=25 C I KA =10mA 50 40 30 20 10 0 10 -1 10 3 10 4 10 Frequency 5 (Hz) 10 6 10 7 -10 10 3 10 4 10 5 Contek Microelectronics Co.,Ltd. CONTEK 10 6 10 7 Frequency (Hz) http://www.contek-ic.com E-mail:sales@contek-ic.com 3 TL431 LINEAR INTEGRATED CIRCUIT TEST CIRCUIT VKA INPUT INPUT VKA IKA VKA INPUT IKA IKA(OFF) R1 IREF ContekTL431 R2 VREF Contek TL431 Contek TL431 VREF VKA=VREF*( 1+R1/R2)+IREF* R1 Fig 7 Test Circuit For VKA=VREF Fig 8 Test Circuit for VKA >= VREF Fig 9 Test Circuit For IKA(OFF) APPLICATION CIRCUIT Vi Vo Vi IN Contek7805 Vi COMMON R1 R1 VREF R1 VREF VREF R2 R2 R2 Contek TL431 Contek TL431 Contek TL431 Vo=(1+R1/R2)*VREF Vo=(1+R1/R2)*VREF Vo=(1+R1/R2)*VREF Fig 10 Shutdown Regulator Fig 11 Output Control of a Three -Terminal Fixed Regulator Vi Io Vo Vo Vo OUT Fig 12 Higher-current Shunt Regulator Io Vi Vo RCL Rs Rs Contek TL431 IO=VREF/RS Contek TL431 Fig 13 Constant-current Sink RS=VREF/RCL Fig 14 Current Limiting or Current Source Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 4