ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Description Pin Assignments ZXRE250 NEW PRODUCT The ZXRE250 and ZXRE252 are three terminal adjustable shunt regulators offering excellent temperature stability and output current handling capability up to 100mA. The output voltage may be set to any chosen voltage between 2.5 and 36 volts by selection of two external divider resistors. ZXRE250 has the same electrical specifications as the industry standard ‘431 except that it features a very low minimum cathode current for regulation. The typical value of 40µA makes the parts ideal for very low power applications. (Top View) ANODE 3 REF 2 CATHODE 1 SOT23 The devices can be used as a replacement for zener diodes in many applications requiring an improvement in zener performance. The ZXRE250/2 is available in 2 grades with initial tolerances of 1% and 0.5% for the A and B grades respectively. Features • • • • • • • • Minimum cathode current for regulation: 40μA (typ) Temperature range -40 to 125ºC Reference Voltage Tolerance at 25°C o ZXRE250A: 2.495V ± 1.0%. o ZXRE250B: 2.495V ± 0.5% Low Output Noise 0.2Ω Typical Output Impedance Sink Current Capability: 0.065mA to 100mA Adjustable Output Voltage: VREF to 36V SOT23 and SOT25: Available in “Green” Molding Compound (No Br, Sb) and Lead Free Finish/ RoHS Compliant (Note 1) (Top View) NC 1 Leave floating or connect to pin 5 2 CATHODE 3 5 ANODE 4 REF SOT25 ZXRE252 (Top View) ANODE 3 CATHODE 2 REF 1 SOT23 Applications • • • • Opto-Coupler Linearisers Shunt Regulators Improved Zener Variable Reference Notes: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at http://www.diodes.com/products/lead_free.html. ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 1 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Absolute Maximum Ratings (Note 2) Symbol Unit Cathode Voltage 40 V IKA Continuous Cathode Current 150 mA -0.050 to +10 mA TJ TST NEW PRODUCT Rating VKA IREF PD Notes: Parameter Reference Input Current +150 ° -55 to +150 ° Operating Junction Temperature Storage Temperature SOT23 SOT25 Power Dissipation (Notes 3, 4) C C 330 500 mW mW 2. Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may reduce device reliability. Unless otherwise stated voltages specified are relative to the ANODE pin. 3. TJ, max =150°C. 4. Ratings apply to ambient temperature at 25°C. Recommended Operating Conditions Symbol Min Max Unit Cathode Voltage VREF 36 V IKA Cathode Current 0.065 100 mA TA Operating Ambient Temperature -40 125 °C VKA Parameter ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 2 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Electrical Characteristics (TA = +25°C, unless otherwise noted) NEW PRODUCT Symbol Parameter VREF Reference voltage VDEV Deviation of reference voltage over full temperature range (Note 5) ΔVREF ΔVKA Ratio of the change in reference voltage to the change in cathode voltage Reference input current IREF IREF deviation over full temperature range (Note 5) ΔIREF IKA(MIN) IKA(OFF) |ZKA| θJA Notes: Test Conditions ZXRE250A VKA = VREF, IKA = 10mA ZXRE250B TA = 0 to 70 oC VKA = VREF, TA = -40 to 85 oC IKA = 10mA TA = -40 to 125 oC VKA = 10V to VREF IKA = 10mA VKA = 36V to 10V Minimum cathode current for regulation Off-state current Dynamic output impedance (Note 6) Thermal Resistance Junction to Ambient Min 2.470 2.482 Typ. 2.495 2.495 6 14 14 -1.4 Max 2.520 2.507 16 34 34 -2.7 Unit V V mV mV mV mV/V -1 -2 mV/V IKA = 10mA, R1 = 10KΩ, R2 = ∞ o TA = 0 to 70 C IKA = 10mA, R1 TA = -40 to 85 oC = 10KΩ, R2 = ∞ TA = -40 to 125 oC 1 0.8 0.8 0.8 4 1.2 2.5 2.5 μA μA μA μA VKA = VREF 40 65 μA 0.05 0.2 380 250 0.5 0.5 μA Ω o C/W o C/W VKA = 36V, VREF = 0V VKA = VREF, f = 0Hz SOT23 SOT25 5. Deviation of VDEV, and ΔIREF are defined as the maximum variation of the values over the full temperature range. The average temperature coefficient of the reference input voltage αVREF is defined as: Vmax VDEV X 106 VREF @ 25ºC αVREF = ppm/ºC T2 – T1 Vmin Where: T2 – T1 = full temperature change. αVREF can be positive or negative depending on whether the slope is VDEV = Vmax - Vmin positive or negative. Notes: 6. The dynamic output impedance, RZ, is defined as: ZKA = ΔVKA ΔIKA T1 Temperature T2 When the device is programmed with two external resistors R1 and R2, the dynamic output impedance of the overall circuit, is defined as: Z’ = ΔV ΔI ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 ≈ ZKA 1+ R1 R2 3 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR NEW PRODUCT Test Circuits Figure 1. Test circuit for VKA = VREF Figure 2. Test circuit for VKA > VREF Figure 3. Test circuit for IOFF ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 4 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Typical Performance Characteristics 2600 0.2 IKA = 10mA TA = 25 °C 2560 IREF Reference Current ( μA) V REF Reference Voltage (mV) R1 = 10KΩ R2 = ∞ IKA = 10mA V KA = VREF 2540 2520 2500 2480 2460 0.15 0.1 0.05 2440 2420 2400 -55 -35 0 -55 -15 5 25 45 65 85 105 125 TA Free Air Temperature ( °C) Reference Voltage vs. Free Air Temperature -35 -15 5 25 45 65 85 105 125 TA Free Air Temperature ( °C) Reference Current vs. Free Air Temperature 200 150 V KA = VREF V KA = VREF TA = 25 °C TA = 25 °C IKA Cathode Current ( μA) 100 IKA Cathode Current (mA) NEW PRODUCT 2580 50 0 100 IKMIN 0 -50 -100 -2 0 1 2 V KA Cathode Voltage (V) Cathode Current vs. Cathode Voltage -1 ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 3 -100 -2 5 of 14 www.diodes.com 0 1 2 V KA Cathode Voltage Cathode Current vs. Cathode Voltage -1 3 May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Typical Performance Characteristics (cont.) 0.50 -0.2 V KA = 36V V REF = 0 0.40 -0.4 0.35 dV REF/dV KA (mV/V) IKOFF Off-State Cathode Current (μ A) V KA = 3V t o 36V -0.3 0.30 0.25 0.20 0.15 -0.5 -0.6 -0.7 -0.8 0.10 -0.9 0.05 0.00 -75 -25 0 25 50 75 100 125 TA Free Air Temperature (°C) Off-State Cathode Current vs. Free Air Temperature -50 -1.0 -50 75 0 25 50 100 125 TA Free Air Temperature (C) Ratio of Delta Reference Voltage to Delta Cathode Voltage vs. Free Air Temperature -25 400 V N = Equivalent Input Noise Voltage nV/√Hz NEW PRODUCT 0.45 380 IKA = 10mA V KA = VREF TA = 25°C 360 340 320 300 280 260 240 220 200 10 100 1K 10K 100K f- Frequency (Hz) Equivalent Input Noise Voltage vs. Frequency ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 6 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Typical Performance Characteristics (cont.) Vn - Equivalent Input Noise Voltage - μ V NEW PRODUCT 15 IKA = 10mA V KA = VREF 10 TA = 25 °C 5 0 -5 -10 -15 0 1 2 3 4 5 6 7 8 9 10 Time (Seconds) Equivalent Input Noise Voltage Over A 10-S Period Figure 4. Test circuit for noise input voltage ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 7 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Typical Performance Characteristics (cont.) A V Small-Signal Voltage Amplification (dB) IKA = 10mA TA = 25 °C 60 50 40 30 20 10 0 100 10M 10K 100K 1M f Frequency (Hz) Small-Signal Voltage Amplification vs. Frequency 1K Test circuit for voltage amplification 100.0 IKA = 10mA TA = 25 °C ZKA Reference Impedance (Ω ) NEW PRODUCT 70 10.0 1.0 0.1 Test circuit for reference impedance 0.0 1K 100K 1M f Frequency (Hz) Reference Impedance vs. Frequency 10K ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 10M 8 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Typical Performance Characteristics (cont.) 6 TA = 25 °C Input Input and Output Voltage (V) 4 3 Out put 2 Test Circuit for Pulse Response 1 0 0 1 2 3 4 5 6 7 t Time (μs) Pulse Response 8 9 10 100 90 TA = 25 °C D D 80 IKA - Cathode Current - mA NEW PRODUCT 5 C C A B 70 Stable Stable Stable 60 50 B Test Circuit for Curve A 40 30 20 10 A VKA = V REF B V KA = 5V C V KA = 10V D V KA = 15V 0 0.00001 0.0001 0.001 0.01 0.1 1 C L -Load Capacitance - uF Stability Boundary Conditions 10 Test circuit for curves B, C, D Test Circuit for Curves B, C, D The device is stable under all conditions with a load capacitance not exceeding 50pF. The device is stable under all conditions with a load capacitance between 5nF and 20nF. The device is stable under all conditions with a load capacitance exceeding 300nF. With a cathode current not exceeding 5mA, the device is stable with any load capacitance. ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 9 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Applications Information NEW PRODUCT Higher Current Shunt Regulator Shunt Regulator Output Control of a Three Terminal Fixed Regulator Series Regulator Single Supply Comparator with Temperature Compensated Threshold ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 Over Voltage / Under Voltage Protection Circuit 10 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Ordering Information ZXRE25 X X XX - 7 NEW PRODUCT Pinout variation 0: Standard pinout Tolerance A: ±1.0% Package SA: SOT23 2: Reversed pinout in SOT23 B: ±0.5% W5: SOT25 Packing 7: Tape & Reel 7” Tape and Reel Ammo Box Device (Note 7) Package Code Packaging (Note 5) Quantity Part Number Suffix Quantity Part Number Suffix ZXRE250A(B)SA-7 ZXRE250A(B)W5-7 ZXRE252A(B)SA-7 SA W5 SA SOT23 SOT25 SOT23 3000/Tape & Reel 3000/Tape & Reel 3000/Tape & Reel -7 -7 -7 NA NA NA NA NA NA Notes: 7. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at http://www.diodes.com/datasheets/ap02001.pdf. 8. Suffix (B) denotes ZXRE250B (0.5% tolerance) device. ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 11 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Marking Information (1) SOT23 ( Top View ) 3 NEW PRODUCT XX Y W X 1 2 XX : Identification code Y : Year 0~9 W : Week : A~Z : 1~26 week; a~z : 27~52 week; z represents 52 and 53 week X : A~Z : Green Device Package Identification Code ZXRE250ASA ZXRE250BSA ZXRE252ASA ZXRE252BSA SOT23 SOT23 SOT23 SOT23 DA DB FA FB (2) SOT25 ( Top View ) 4 7 5 XX Y W X 1 2 3 XX : Identification code Y : Year 0~9 W : Week : A~Z : 1~26 week; a~z : 27~52 week; z represents 52 and 53 week X : A~Z : Green Device Package Identification Code ZXRE250AW5 ZXRE250BW5 SOT25 SOT25 DA DB ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 12 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Package Outline Dimensions (All Dimensions in mm) NEW PRODUCT (1) Package type: SOT25 (2) Package Types: SOT23 ZXRE250/ZXRE252 Document number: DS35228 Rev. 3 - 2 13 of 14 www.diodes.com May 2011 © Diodes Incorporated ZXRE250/ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 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