SS431/G Adjustable Precision Shunt Regulator FEATURES DESCRIPTION Low voltage operation (2.5V) The SS431 is a low-voltage three-terminal adjustable shunt Adjustable output voltage from VO = V REF to 18V regulator with a guaranteed thermal stability over the applicable Wide operating current range from 0.4mA to 100mA temperature range. The output voltage can be set to any value Low dynamic output impedance 0.5Ω max. between VREF (approximately 2.5V) to 18V with two external ESD rating is 5.5kV (per MIL-STD 883D) resistors (see application circuit). This device has a typical output Pb-free lead finish available. impedance of 0.2 ohms. Active output circuitry provides very sharp APPLICATIONS turn-on Linear Regulators characteristics, making this device an excellent replacement for Zener diodes in many applications. Adjustable Supplies The SS431 is characterized for operation from 0°C to 105°C, Switching Power Supplies and three package options (SOT-23, SOT-89, and TO-92) allow Battery Operated Computers the designer the opportunity to select the proper package for his Instrumentation application. The SS431 is available with a Pb-free lead finish - order as SS431Gxx. Computer Disk Drives PIN CONFIGURATION BLOCK DIAGRAM SOT-23 (Top view) Anode 2 Cathode 1 Reference Cathode Ref + 3 Vref SOT-89 (Top view) Anode 3 Cathode 2 Anode 1 Reference TO-92 (Top view) SYMBOL Cathode 3 Cathode 2 Anode 1 Reference Ref. Anode Rev.2.02 3/11/2004 www.SiliconStandard.com 1 of 7 SS431/G ABSOLUTE MAXIMUM RATINGS over ambient temp. range. Parameter Symbol Maximum Units !" θ " " # $ % ELECTRICAL CHARACTERISTICS ! !! !" ∆ ∆ # #$ #$ % ∆ & '& ∞ µ & '& ∞ $ $ µ (!" $ #)!" * + & $ µ ," & ≤'- $ $ Rev.2.02 3/11/2004 www.SiliconStandard.com 2 of 7 SS431/G TYPICAL PERFORMANCE CHARACTERISTICS !"#!$%& & Rev.2.02 3/11/2004 www.SiliconStandard.com !"#!$%& & 3 of 7 SS431/G TEST CIRCUITS APPLICATION INFORMATION Where: T2−T1=full temperature change. αVREF can be positive or negative depending on whether the slope is positive or negative. Example: VDEV= 7.0mV, VREF= 2495mV, T2−T1= 105°C, slope is negative. VMAX VDEV = VMAX-VMIN VMIN 7.0mV 106 2495mV αVREF = = −27ppm/°C 105 °C T1 TEMPERATURE T2 Deviation of reference input voltage, V DEV, 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, αVREF is defined as: ppm ∆VREF = °C Rev.2.02 3/11/2004 6 VMAX - VMIN 6 VDEV ± ± 10 10 REF REF V (at 25 C) V (at 25 ° C) ° = T2 − T1 T2 − T1 Note 4. The dynamic output impedance, Rz, is defined as: RZ = ∆VZ ∆IZ When the device is programmed with two external resistors, R1 and R2, (see Fig. 2), the dynamic output impedance of the overall circuit, is defined as: www.SiliconStandard.com rz = [ ] ∆V ≅ Rz 1+ R1 R2 ∆I 4 of 7 SS431/G APPLICATION EXAMPLES VIN R1 RCL IOUT VIN SS431 RS SS431 R1 IOUT=VREF/ RCL IOUT=VREF /RS Current Limiter or Current Source VIN RIN Constant-Current Sink VIN VOUT R3 FUSE R3 VOUT R1 R1 SS431 R2 SS431 R2 VOUT ≅ (1+R1/R2) x VREF VLIMIT ≅ (1+R1/R2) x VREF Higher-Current Shunt Regulator Crow Bar VIN R1A R3 R1B C1 SS431 Output turns ON when Low Limit <VIN < High Limit + SS431 R2A R2B R4 R5 VBE Low Limit≅ VREF ( 1+ R1B/ R2B )+ VBE High Limit ≅ VREF ( 1+ R1A/ R2A ) Over-Voltage/Under-Voltage Protection Circuit Rev.2.02 3/11/2004 www.SiliconStandard.com 5 of 7 SS431/G PHYSICAL DIMENSIONS SOT-23 ! + + ! ! " $%$ && && $%'$ $%$ %'$ %($ %* %$ %* %$ && $%$ $%$$ $%$ $%($ $%$ %$$ %)$ %*$ %*$ %*$ %*$ # $%$ && && $%)$ $%*$ %$ %$$ %'* %,$ %'* %,$ && SOT-89 Rev.2.02 3/11/2004 www.SiliconStandard.com 6 of 7 SS431/G PHYSICAL DIMENSIONS TO-92 ORDERING INFORMATION SS431(G)xBxx TR: Tape and Reel Packing Bandgap tolerance B = 1% Example: SS431GNBTR Package type N = SOT-23-3 T = TO-92 G = SOT-89 Lead finish option: G for Pb-free lead finish SS431 with 1% tolerance in SOT-23-3 with pb-free lead finish shipped on tape and reel Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. Rev.2.02 3/11/2004 www.SiliconStandard.com 7 of 7