TS431-Z Adjustable Precision Shunt Regulator SOT-23 TS431-Z Pin Definition: 1. Reference 2. Cathode 3. Anode TS431AR-Z Pin Definition: 1. Cathode 2. Reference 3. Anode General Description TS431 integrated circuits are three-terminal programmable shunt regulator diodes. These monolithic IC voltage references operate as a low temperature coefficient zener which is programmable from VREF to 36 volts with two external resistors. These devices exhibit a wide operating current range to 250mA with a typical dynamic impedance of 0.2. The characteristics of these references make them excellent replacements for zener diodes in many applications such as digital voltmeters, power supplies, and op amp circuitry. The 2.495V reference makes it convenient to obtain a stable reference from 5.0V logic supplies, and since The TS431 operates as a shunt regulator, it can be used as either a positive or negative stage reference. Features Programmable Output Voltage up to 36V TS431A - VREF 2.495V 1% tolerance TS431B - VREF 2.495V 0.5% tolerance Fast Turn-On Response Sink Current Capability: 200mA Low Dynamic Output Impedance: 0.2 (Typ) Min. Operating Cathode Current: 0.2mA (Typ) Halogen Free Ordering Information Part No. Package Packing TS431ACX-Z RFG SOT-23 3kpcs / 7" Reel TS431ARCX-Z RFG SOT-23 3kpcs / 7" Reel TS431BCX-Z RFG SOT-23 3kpcs / 7" Reel Note: "G" denotes for Halogen- and Antimony-free as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds Block Diagram Absolute Maximum Ratings (TA = 25oC unless otherwise noted) Parameter Symbol Limit Unit VKA 36 V IK +250 mA Reference Input Current Range IREF 10 mA Power Dissipation PD 0.25 Cathode Voltage Continuous Cathode Current Range Operating Temperature Range -20 ~ +85 TJ -40 ~ +125 o TSTG -40 ~ +125 o TOPER Junction Temperature Storage Temperature Range Thermal Resistance Junction to Ambient W o RJA 156 C C C o C/W 2 Note: RJA is measured with the PCB copper area of approximately 1 in (Multi-Layer) 1/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Electrical Characteristics (TA=25oC, unless otherwise specified) Parameter Symbol Reference TS431A voltage TS431B Deviation of reference input voltage VREF VREF Test Conditions Min 2.470 VKA =VREF, IK =10mA (Figure 1) 2.483 VKA = VREF, IK =10mA (Figure 1) o TA=-20~85 C Typ 2.495 Max 2.520 2.507 -- 6 20 Unit V mV Radio of change in Vref to VREF IKA =10mA, VKA = 10V to VREF -- -1.2 -2.0 change in cathode Voltage /VKA (Figure 2) VKA = 36V to 10V -- -1.0 -2.0 -- 1.5 3.5 A -- 0.4 1.2 A Reference Input current Deviation of reference input current, over temp. Off-state Cathode Current Dynamic Output Impedance Minimum operating cathode current IREF IREF R1=10K, R2= , IKA =10mA (Figure 2) R1=10K, R2= , IKA =10mA o TA=-20~85 C (Figure 2) mV/V IKA (off) VREF =0V (Figure 3), VKA =36V -- 0.1 1.0 A | ZKA | f<1KHz, VKA = VREF (Figure 1) -- 0.2 0.5 VKA = VREF (Figure 1) -- 0.2 0.5 mA IKA (min) * The deviation parameters VREF and IREF are defined as difference between the maximum value and minimum value obtained over the full operating ambient temperature range that applied. * The average temperature coefficient of the reference input voltage, VREF is defined as: Where: T2-T1 = full temperature change. VREF can be positive or negative depending on whether the slope is positive or negative. o o o o Example: Maximum VREF=2.496V at 30 C, minimum VREF =2.492V at 0 C, VREF =2.495V at 25 C, T=70 C VREF | = [4mV / 2495mV] * 106 / 70oC 23ppm/oC Because minimum VREF occurs at the lower temperature, the coefficient is positive. * The dynamic impedance ZKA is defined as: | ZKA | = VKA / IKA * When the device operating with two external resistors, R1 and R2, (refer to Figure 2) the total dynamic impedance of the circuit is given by: | ZKA | = v / i | ZKA | * ( 1 + R1 / R2) 2/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Test Circuits Figure 1: VKA = VREF Figure 2: VKA > VREF Figure 3: Off-State Current Additional Information - Stability When The TS431A/431B is used as a shunt regulator, there are two options for selection of CL, are recommended for optional stability: A) No load capacitance across the device, decouple at the load. B) Large capacitance across the device, optional decoupling at the load. The reason for this is that TS431A/431B exhibits instability with capacitances in the range of 10nF to 1uF (approx.) at light cathode current up to 3mA (typ). The device is less stable the lower the cathode voltage has been set for. Therefore while the device will be perfectly stable operating at a cathode current of 10mA (approx.) with a 0.1uF capacitor across it, it will oscillate transiently during start up as the cathode current passes through the instability region. Select a very low capacitance, or alternatively a high capacitance (10uF) will avoid this issue altogether. Since the user will probably wish to have local decoupling at the load anyway, the most cost effective method is to use no capacitance at all directly across the device. PCB trace/via resistance and inductance prevent the local load decoupling from causing the oscillation during the transient start up phase. Note: if the TS431A/431B is located right at the load, so the load decoupling capacitor is directly across it, then this capacitor will have to be 1nF or 10uF. 3/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Applications Examples (Continue) Figure 4: Voltage Monitor Figure 5: Output Control for Three Terminal Fixed Regulator Figure 6: Shunt Regulator Figure 7: High Current Shunt Regulator Figure 8: Series Pass Regulator Figure 9: Constant Current Source 4/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Applications Examples (Continue) Figure 10: TRIAC Crowbar Vin <Vref >Vref Figure 11: SCR Crowbar Vout V+ 0.74V Figure 12: Single-Supply Comparator with Temperature-Compensated Threshold Figure 13: Constant Current Sink Figure 14: Delay Timer 5/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Typical Performance Characteristics Figure 15: Small-Signal Voltage Gain and Phase Shirt vs. Frequency Figure 16: Reference Impedance vs. Frequency 6/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Typical Performance Characteristics (Continue) Figure 17: Stability Boundary Condition Figure 18: Pulse Response 7/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Electrical Characteristics Figure 19: Reference Voltage vs. Temperature Figure 20: IREF vs. Temperature Figure 21: IKA vs. VKA (uA) Figure 22: IKA vs. VKA (mA) 8/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator SOT-23 Mechanical Drawing Unit: Millimeters Marking Diagram Rx = Device Code R1 = TS431A (1%) RA = TS431AR (1%) R2 = TS431B (0.5%) Y = Year Code 2 = 2012, 3 = 2012, 4 = 2014 ............. W = Week Code 01 ~ 26 (A~Z) 27 ~ 52 (a ~ z) X = Internal ID Code 9/10 Version: C14 TS431-Z Adjustable Precision Shunt Regulator Notice Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, to any intellectual property rights is granted by this document. Except as provided in TSC's terms and conditions of sale for such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of TSC products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify TSC for any damages resulting from such improper use or sale. 10/10 Version: C14