ADJUSTABLE PRECISION ZR431 ZENER SHUNT REGULATOR ISSUE 5 DECEMBER 2002 DEVICE DESCRIPTION FEATURES The ZR431 is a three terminal adjustable Surface mount SOT223 and SOT23 packages shunt regulator offering excellent temperature stability and output current TO92 package handling capability up to 100mA. The output 2%, 1 % and 0.5% tolerance voltage may be set to any chosen voltage between 2.5 and 20 volts by selection of two Max. temperature coefficient 55 ppm/C external divider resistors. Temperature compensated for operation over the full temperature range The devices can be used as a replacement Programmable output voltage for zener diodes in many applications requiring an improvement in zener 50 A to 100mA current sink capability performance. Low output noise APPLICATIONS Shunt regulator Series regulator Voltage monitor Over voltage/ under voltage protection Switch mode power supplies SCHEMATIC DIAGRAM V Z V ref G nd 4-189 78ZR431 ABSOLUTE MAXIMUM RATING Cathode Voltage (V ) 20V Power Dissipation (T =25C,T =150C) Z amb jmax Cathode Current 150mA SOT23 330mW Operating Temperature -40 to 85C TO92 780mW Storage Temperature -55 to 125C SOT223 2W Recommended Operating Conditions Min Max Cathode Voltage Vref 20V Cathode Current 50 A 100mA ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):T =25C amb VALUE SYMBOL PARAMETER UNITS CONDITIONS MIN TYP MAX Reference Voltage 2% V 2.45 2.50 2.55VI =10mA (Fig1), V =V ref L Z ref 1% 2.475 2.50 2.525 (1) 0.5% 2.487 2.50 2.513 Deviation of Reference Input V 8.0 17 mV I =10mA, V =V dev L Z ref Voltage over Temperature T =full range (Fig1) a Ratio of the change in -1.85 -2.7 mV/V V from V to 10V V ref Z ref Reference Voltage to the I =10mA (Fig2) Z V Z Change in Cathode -1.0 -2.0 mV/V V from 10V to 20V Z Voltage I =10mA (Fig2) Z Reference Input Current I 0.12 1.0 A R1=10k, R2=O/C, l =10mA ref L (Fig2) Deviation of Reference I 0.04 0.2 A R1=10k, R2=O/C, I =10mA L ref Input Current over T =full range (Fig2) a Temperature Minimum Cathode I 35 50 V =V (Fig1) A Zmin Z ref Current for Regulation Off-state Current I 0.1 A V =20V, V =0V (Fig3) Zoff Z ref Dynamic Output Impedance R 0.75 V =V (Fig1), f=0Hz Z Z ref (1) 0.5% SOT23 only. For definitions of reference voltage temperature coefficient and dynamic output impedance see NOTES following DC TEST CIRCUITS 4-190 78