ADJUSTABLE PRECISION ZENER SHUNT REGULATOR ZH431 Issue 2 - February 1998 DEVICE DESCRIPTION FEATURES The ZH431 is a three terminal adjustable s hu n t r e g u l a t or o f f e r i n g e xc el l e nt temperature stability and output current handling capability up to 30mA. The output voltage may be set to any chosen voltage between 2.5 and 36 volts by selection of two external divider resistors. • • • • • The devices can be used as a replacement for zener diodes in many applications r e qu i r i n g a n i mpr o ve me nt i n z e ner performance.They are also ideal for use in the feedback circuits of off line SMPUs as well as many general purpose regulator and reference applications where initial accuracy and low temperature coefficient are key requirements. • • • Surface mount SO8, SOT223,SOT23 and SOT89 packages TO92 package 2% and 1% tolerance Maximum temperature coefficient 55 ppm/°C Temperature compensated for operation over the full temperature range Programmable output voltage 50µA to 30mA current sink capability Low output noise APPLICATIONS • • • • • Note: ZH431 is not recommended for new designs. Refer to ZR431 Shunt regulator Series regulator Voltage monitor Over voltage/ under voltage protection Switch mode power supplies SCHEMATIC DIAGRAM VZ V ref Gnd 4-15 ZH431 ABSOLUTE MAXIMUM RATING Power Dissipation (Tamb=25°C, Tjmax=150°C) SOT23 330mW TO92 780mW SOT223 2W SO8 780mW SOT89 1.5W Cathode Voltage (VZ) 40V Cathode Current 50mA Operating Temperature -40 to 85°C Storage Temperature -55 to 125°C Recommended Operating Conditions Min Max Cathode Voltage Vref 36V Cathode Current 50µA 30mA ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):Tamb=25°C VALUE SYMBOL PARAMETER MIN Reference Voltage 2% Vref 1% TYP MAX UNITS CONDITIONS 2.45 2.50 2.55 V 2.475 2.50 2.525 IL=10mA (Fig1), VZ=Vref Deviation of Reference Input Voltage over Temperature Vdev 8.0 17 mV IL=10mA, VZ=Vref Ta=full range (Fig1) Ratio of the change in Reference Voltage to the Change in Cathode Voltage ∆Vref ∆VZ -0.7 -2.7 mV/V VZ from Vref to 10V IZ=10mA (Fig2) -0.6 -2.0 mV/V VZ from 10V to 36V IZ=10mA (Fig2) Reference Input Current Iref 0.15 1.0 µA R1=10k, R2=O/C, lL=10mA (Fig2) Deviation of Reference Input Current over Temperature ∆Iref 0.06 0.2 µA R1=10k, R2=O/C, IL=10mA Ta=full range (Fig2) Minimum Cathode Current for Regulation IZmin 21 50 µA VZ=Vref (Fig1) 0.75 Ω VZ=Vref (Fig1), f=0Hz Dynamic Output Impedance RZ Deviation of reference input voltage, Vdev, is defined as the maximum variation of the reference input voltage over the full temperature range. The average temperature coefficient of the reference input voltage, Vref is defined as: Vdev x 1000000 Vref (T1−T2) The dynamic output impedance, Rz, is defined as: ∆VZ RZ = ∆IZ When the device is programmed with two external resistors, R1 and R2, (fig 2) , the dynamic output impedance of the overall circuit, R’, is defined as: R1 R’=Rz (1+ ) R2 Vref (ppm ⁄ °C)= Vmax Vmin Vdev = Vmax - Vmin T1 Temperature T2 4-16 ZH431 TYPICAL CHARACTERISTICS 200 Change in Reference Voltage (mV) 5 Reference Current (nA) Vref= Vz Iz= 10mA 180 160 140 120 100 -40 -20 0 20 40 80 60 Temperature (°C) 26 Vref= Vz 24 22 20 18 16 14 12 -40 -20 0 20 40 80 60 -5 -10 -15 -20 -25 0 5 10 15 20 25 30 40 35 Cathode Voltage (V) Change in Vref v Cathode Voltage Dynamic Impedance (Ohms) Minimum Cathode Current (uA) Reference Current v Temperature 0 100 1mA 10 Vref=Vz 10mA 1 0.1 0.01 100 Temperature (°C) 1k 10k 100k 1M Frequency (Hz) Dynamic Impedance v Frequency Cathode Current v Temperature 2.52 2.0 Power Dissipation (W) Iz= 10mA Reference Voltage (V) 2.51 2.50 2.49 2.48 2.47 -40 -20 0 20 40 60 SOT223 1.0 SOT89 S08/T092 SOT23 0 25 80 50 75 Ambient Temperature (°C) Temperature (°C) Power Dissipation Derating Reference Voltage v Temperature 4-17 100 ZH431 TYPICAL CHARACTERISTICS VZ 70 50 Open Loop Gain (dB) IZ 15k 60 230Ω 9µF 40 + 30 8k25 20 - 10 0 100 10k 1k 100k 1M IZ = 10mA, TA = 25°C Frequency (Hz) Gain v Frequency Test Circuit for Open Loop Voltage Gain 220Ω Input Monitor 3.0 VZ REPETITIVE PULSE Voltage Swing (V) 2.0 SINGLE PULSE Pulse Generator 1.0 50Ω 0 5 INPUT 0 TA = 25°C 0 0.05 0.1 0.15 0.2 0.25 Time (µs) Pulse Response Test Circuit for Pulse Response Input 30 Cathode Current (mA) 25 VZ IZ 20 Unstable 15 150 10k Stable Stable 10 5 0 10p 100p 1000p 0.01µ 0.1µ 1µ Load Capacitance (F) Stability Boundary Conditions Vref < VZ < 40, IZ = 10mA, TA = 25°C Test Circuit for Stability Boundary Conditions 4-18 ZH431 DC TEST CIRCUITS IL Input Fig 1 – Test Circuit for Vz=Vref Fig 2 – Test Circuit for Vz>Vref 4-19 ZH431 APPLICATION CIRCUITS V+ Vout V+ Vout R1 R1 Vref Vref R2 Vout = R2 R1 1+ Vref Vout = R2 1+ R1 Vref R2 SHUNT REGULATOR HIGHER CURRENT SHUNT REGULATOR V+ ZSR*** V+ Vout Out In Common 30 R1 0.01µF Vref R1 R2 Vout Vref R2 Vout MIN = Vref + Vreg Vout = 1+ R1 Vref R2 Vout = 1+ R1 Vref R2 OUTPUT CONTROL OF A THREE TERMINAL FIXED REGULATOR SERIES REGULATOR V+ V+ R1A OUTPUT R1B Vref INPUT V on 2V Vref V off = V+ R2A V TH = 2.5V R2B Low limit = High limit = SINGLE SUPPLY COMPARATOR WITH TEMPERATURE COMPENSATED THRESHOLD 1+ R1B Vref R2B 1+ R1A Vref R2A OVER VOLTAGE / UNDER VOLTAGE PROTECTION CIRCUIT 4-20 OUTPUT ZH431 CONNECTION DIAGRAMS SO8 Package Suffix – N8 SOT223 Package Suffix – G Top View Top View – Pin 4 floating or connected to pin 2 SOT23 Package Suffix – F TO92 Package Suffix – C Top View Bottom View SOT89 ORDERING INFORMATION Part Number Package Tol. % Part Mark ZH431C01 TO92 1.0 ZH43101 ZH431C02 TO92 2.0 ZH43102 ZH431G01 SOT223 1.0 ZH43101 ZH431G02 SOT223 2.0 ZH43102 ZH431F01 SOT23 1.0 43H ZH431F02 SOT23 2.0 43G ZH431Z01 SOT89 1.0 43H ZH431Z02 SOT89 2.0 43G ZH431N801 SO8 1.0 ZH43101 ZH431N802 SO8 2.0 ZH43102 Package Suffix – Z Top View – Pin 4 floating or connected to pin 2 4-21