X431 LINEAR INTEGRATED CIRCUIT PROGRAMMABLE PRECISION REFERENCE DESCRIPTION 1 The X431 is 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.These devices have provides a very sharp turn-on characteristic, making these devices excellent replacement for zener diodes in many applications. TO-92 1 FEATURE *Programmable output Voltage to 36V *Low dynamic output impedance 0.2Ω *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 SOT-23-3 1:Ref; 2:Anode; 3:Cathode BLOCK DIAGRAM CATHODE REFERENCE CATHODE (K) REFERENCE (R) ANODE(A) 2.5V Vref ANODE 2005.06.06 V1.1 1 LINEAR INTEGRATED CIRCUIT X431 ABSOLUTE MAXIMUM RATINGS (Operating temperature range applies unless otherwise specified)) CHARACTERISTICS SYMBOL Cathode Voltage Cathode Current Range(Continuous) Reference Input Current Range Power Dissipation VKA IKA Iref PD Operating temperature Storage temperature Temperature Topr Tstg VALUE UNITS 37 -100~+150 0.05~+10 TO-92 770 SOT-23-3 370 0~70 -65~+150 °C V mA mA mW °C °C RECOMMENDED OPERATING CONDITIONS Characteristic Cathode Voltage Cathode Current Symbol Min VKA IKA VREF 1.0 Typ Max Unit 36 100 V mA ELECTRICAL CHARACTERISTICS(Ta=25°C,unless otherwise specified) Characteristic Reference Input Voltage 1 0.5% 1% 2% Reference Input Voltage 2* 0.5% 1% 2% Deviation of reference Input Voltage Over temperature(note 1) Ratio of Change in Reference Input Voltage to the Change in Cathode Voltage Reference Input Current Deviation of Reference Input Current Over Ful l Temperature Range Minimum cathode current for regulation Off-state cathode Current Dynamic Impedance ： Symbol Test conditions MIN Vref VKA=VREF,IKA=10mA Vref VKA=VREF,IKA=10mA ∆Vref/∆T VKA=VREF,IKA=10mA TMIN≤TA≤TMAX ∆VKA=10V~VREF IKA=10mA ∆Vref/∆VKA TYP MAX UNIT 2.488 2.50 2.512 2.475 2.50 2.525 2.450 2.50 2.550 2.483 2.495 2.507 2.470 2.495 2.520 2.445 2.495 2.545 4.5 17 mV -1.0 -2.7 mV/V V V Iref ∆Iref/∆T ∆VKA=36V~10V IKA=10mA,R1=10k ,R2=∞ IKA=10mA,R1=10kΩ,R2=∞ TA= full Temperature -0.5 1.5 0.4 -2.0 4 1.2 µA µA IKA(min) VKA=VREF 0.45 1.0 mA IKA(OFF) ZKA VKA=36V,VREF=0 VKA=VREF,IKA=1 to 100mA f≤1.0kHz 0.05 0.15 1.0 0.5 µA Ω Ω , Note TMIN=0°C,TMAX=+70°C *In order to match the special request of customer 2005.06.06 V1.1 2 X431 LINEAR INTEGRATED CIRCUIT TEST CIRCUITS VKA INPUT INPUT VKA IKA INPUT IKA VKA IKA(OFF) R1 IREF X431 X431 VREF R2 X431 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) TYPICAL APPLICATION Vi Vi Vo IN Vi UTC7805 COMMON R1 R1 VREF R1 VREF VREF R2 R2 Fig 10 Shutdown Regulator Io X431 Vo=(1+R1/R2)*VREF Vo=(1+R1/R2)*VREF Vi R2 X431 X431 Vo Vo OUT Vo=(1+R1/R2)*VREF Fig 11 Output Control of a Three -Terminal Fixed Regulator Fig 12 Higher-current Shunt Regulator Io Vi Vo Vo RCL Rs Rs X431 X431 IO=VREF/RS Fig 13 Constant-current Sink RS=VREF/RCL Fig 14 Current Limiting or Current Source 2005.06.06 V1.1 3 X431 LINEAR INTEGRATED CIRCUIT TYPICAL PERFORMANCE CHARACTERISTICS Fig 1 Cathode Current Vs Cathode Voltage 125 ℃ Ta=25 VKA=VREF ℃ Ta=25 VKA=VREF 600 Cathode Current (µA) Cathode Current (mA) 100 Fig 2 Cathode Current Vs Cahode Voltage 800 75 50 25 0 -25 400 IKA(min) 200 -50 0 -75 -100 -2 -200 -1 0 1 2 -2 3 -1 Cathode Voltage (V) Fig 3 Change in Reference Input Voltage Vs Cathode voltage 0 Ta=25 7 IKA=100mA Ta=25 Input and Output Voltage (V) ℃ -10 -15 -20 -25 -30 4 3 2 0 5 10 15 20 25 30 35 40 0 1 Cathode Voltage (V) 2 3 4 5 6 7 Time (µs) Fig 5 Dynamic Impedance Vs Frequency Fig 6 Small Signal Voltage Amplification Vs Frequency 70 2 ℃ ℃ Ta=25 IKA=1mA~100mA ℃ 60 Voltage Amplification (dB) Ta=25 IKA=0mA to 100mA Impedance (Ω) ℃ 1 0 10 3 5 -40 10 2 6 -35 10 1 Fig 4 Pulse Response -5 Change In Reference INput Voltage (mV) 0 Cathode Voltage (V) 1 0 Ta=25 IKA=10mA 50 40 30 20 10 0 -1 10 10 3 10 4 10 5 10 6 10 -10 3 10 7 Frequency (Hz) 10 4 10 5 10 6 10 7 Frequency (Hz) 2005.06.06 V1.1 4 X431 LINEAR INTEGRATED CIRCUIT PACKAGE DIMENSIONS TO-92 SOT-23-3 2005.06.06 V1.1 5