UTC431 LINEAR INTEGRATED CIRCUIT PROGRAMMABLE PRECISION REFERENCE DESCRIPTION The UTC431 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 26 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. 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 TO-92 1:Ref; 2:Anode; 3:Cathode BLOCK DIAGRAM CATHODE REFERENCE CATHODE (K) REFERENCE (R) ANODE(A) 2.5V Vref ANODE YOUW ANG ELECTRONICS CO.LTD 1 UTC431 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS (Operating temperature range applies unless otherwise specified)) CHARACTERISTICS SYMBOL VALUE UNITS VKA IKA Iref PD 37 -100~+150 0.05~+10 V mA mA 770 1000 0~70 -65~+150 °C mW mW °C °C Cathode Voltage Cathode Current Range(Continuous) Reference Input Current Range Power Dissipation D,Z Suffix Package N Suffix Package Operating temperature Storage temperature Temperature Topr Tstg 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 Symbol Vref Deviation of reference Input Voltage ∆Vref/∆T Over temperature(note 1) Ratio of Change in Reference Input ∆Vref/∆VKA 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 Iref ∆Iref/∆T IKA(min) IKA(OFF) ZKA Test conditions MIN VKA=VREF,IKA=10mA VKA=VREF,IKA=10mA TMIN≤TA≤TMAX ∆VKA=10V~VREF IKA=10mA ∆VKA=36V~10V IKA=10mA,R1=10k,R2=∞ IKA=10mA,R1=10kΩ,R2=∞TA= full Temperature VKA=VREF VKA=36V,VREF=0 VKA=VREF,IKA=1 to 100mA f≤1.0kHz TYP MAX UNIT 2.440 2.495 2.550 V 4.5 17 mV -1.0 -2.7 mV/V -0.5 1.5 0.4 -2.0 4 1.2 µA µA 0.45 1.0 mA 0.05 0.15 1.0 0.5 µA Ω NoteTMIN=0°C,TMAX=+70°C YOUW ANG ELECTRONICS CO.LTD 2 UTC431 LINEAR INTEGRATED CIRCUIT TEST CIRCUITS VKA INPUT INPUT VKA IKA INPUT IKA VKA IKA(OFF) R1 IREF UTC431 UTC431 VREF R2 UTC431 VREF VKA=VREF*(1+R1/R2)+IREF*R1 Fig 8 Test Circuit for VKAVREF Fig 7 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 R2 UTC431 UTC431 UTC431 Vo=(1+R1/R2)*VREF Vo=(1+R1/R2)*VREF Fig 10 Shutdown Regulator Vo Vo OUT Vo=(1+R1/R2)*VREF Fig 11 Output Control of a Three -Terminal Fixed Regulator Fig 12 Higher-current Shunt Regulator Vi Io Vi Vo Io Vo RCL Rs Rs UTC431 UTC431 IO=VREF/RS Fig 13 Constant-current Sink RS=VREF/RCL Fig 14 Current Limiting or Current Source YOUW ANG ELECTRONICS CO.LTD 3 UTC431 LINEAR INTEGRATED CIRCUIT TYPICAL PERFORMANCE CHARACTERISTICS Fig 1 Cathode Current Vs Cathode Voltage Fig 2 Cathode Current Vs Cahode Voltage 800 125 Ta=25k VKA=VREF Ta=25k VKA=VREF 600 Cathode Current (µA) Cathode Current (mA) 100 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 Input and Output Voltage (V) -15 -20 -25 -30 5 4 3 2 1 0 -40 0 5 10 15 20 25 30 35 40 0 1 Cathode Voltage (V) 4 5 6 7 Fig 6 Small Signal Voltage Amplification Vs Frequency Ta=25k 60 Voltage Amplification (dB) Impedance (Ω) 3 70 2 Ta=25k IKA=1mA~100mA IKA=0mA to 100mA 10 2 Time (µs) Fig 5 Dynamic Impedance Vs Frequency 10 3 6 -35 10 2 Ta=25k 7 IKA=100mA Ta=25k -10 1 Fig 4 Pulse Response -5 Change In Reference INput Voltage (mV) 0 Cathode Voltage (V) 1 0 Ta=25k IKA=10mA 50 40 30 20 10 0 -1 10 10 3 10 4 10 5 10 6 10 7 -10 3 10 Frequency (Hz) 10 4 10 5 10 6 10 7 Frequency (Hz) YOUW ANG ELECTRONICS CO.LTD 4