TA431

TMC TA431 ADJUSTABLE PRECISION ZENER SHUNT REGULATOR TA 431 DESCRIPTION The TA431 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 36V with two external resistors. This device has typical dynamic output impedance of 0.2Ω. Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacement for zener diodes in many applications. FEATURE        Programmable output voltage to 36V Low dynamic output impedance 0.2Ωtypical Sink current capability of 1.0mA to 100mA Equivalent full-range temperature coefficient of 500ppm/℃ typical Temperature compensated for operation over full rated operating temperature range Low output noise voltage Fast turn on response EQUIVALENT CIRCUIT Q7 R6 12K Q6 800 R 4 R7 12K Q5 Q3 C2 CATHODE (V z ) V re f C1 R3 2.5K R5 640 Q4 Q2 Q1 R2 1K R1 3.3K ANODE (G N D ) ABSOLUTE MAXIMUM RATINGS 1 TMC Operating temperature range applies unless otherwise specified.) Characteristic Cathode Voltage Cathode Current Range (continuous) Reference Input Current Range Power Dissipation Operating Temperature Range Store temperature Range Symbol Vka Ika IREF PD Topr Tstg TA431 Value 37 -10~+150 10 770 0~+70 -65~+150 Unit V mA mA mW ℃ ℃ ELECTRICAL CHARACTERISTICS (Ta=25℃ unless otherwise specified) Parameter Reference Voltage Conditions Vz=VREF Ii=10mA Deviation of Reference Input Voltage Over Temperature Ratio of the Change in Reference Voltage to the Change in Cathode Voltage Reference Input Current Deviation of Reference Input Current Over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance 0.5% 1.0% 2.0% Vdev Symbol VREF Min 2.485 2.470 2.440 Typ 2.5 2.495 2.495 8.0 Max 2.51 2.52 2.55 17 mV Unit V Vz=VREF, Ii=10mA Iz=10mA Vz=VREF~10V Vz=10~36V ΔVREF/ ΔVz IREF - -1.4 -1.0 2.0 -2.7 -2.0 4.0 mV/V R1=10kΩ,R2=∞ I1=10mA R1=10kΩ,R2=∞I1=10mA μA ΔIREF/ ΔT - 0.4 1.2 μA Vz=VREF Vz=36V,VREF=0V Vz=VREF, Iz=1 to 100mA,fVREF 3.Test circuit for off-state current APPLICATION CIRCUIT V+ V+ VREF R1 R2 V o = ( 1+R 1/R 2 ) V E F R 0.01uF R1 R2 Vo = ( 1+R1/R2 ) REF V Vo Vo 30 1. Shunt Regulator V+ IN 2. Series Regulator LM7805OUT COM MON Vo V+ R1 IN R2 Vth=2.5V O UT V on=2V V o f f =V + GND Vo = ( 1+R1/R2 )REF V VoM IN = V EF+ 5 V R 3.Output Control of a Three Terminal Fixed Regulator 4.Single Supply Comparator with Temperature Compensated Threshold 5.Higher Current Shunt Regulator 6.Crow Bar 3 TMC V+ R1 Vo V+ R1 R2 TA431 Vo R2 Vo=(1+R1/R2)*VREF Vlimit=(1+R1/R2)*VREF CHARACTERISTIC CURVES Outline Drawing 4 TMC TA431 5