ZXRE250/ ZXRE252 VERY LOW CATHODE CURRENT ADJUSTABLE PRECISION SHUNT REGULATOR Description Pin Assignments 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. (Top View) ANODE 3 REF 2 CATHODE 1 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. SOT23 (Top View) 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 two grades with initial tolerances of 1% and 0.5% for the A and B grades respectively. NC 1 Leave floating or connect to pin 5 2 CATHODE 3 5 ANODE 4 REF SOT25 (Top View) Features • • • • • • • • • Minimum Cathode Current for Regulation: 40µA (typ) Temperature Range: -40°C to +125°C Reference Voltage Tolerance at +25°C ZXRE250A: 2.495V ± 1.0% 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 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Notes: ANODE 3 CATHODE 2 REF 1 SOT23 Applications • • • • Opto-Coupler Linearisers Shunt Regulators Improved Zener Variable Reference 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 1 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Absolute Maximum Ratings (Note 4) (@TA = +25°C, unless otherwise specified.) Symbol Parameter VKA IKA IREF TJ TST Cathode Voltage Continuous Cathode Current Reference Input Current Operating Junction Temperature Storage Temperature PD Power Dissipation (Notes 5 & 6) Notes: SOT23 SOT25 Rating Unit 40 150 -0.050 to +10 +150 -55 to +150 330 500 V mA mA °C °C mW mW 4. 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. 5. TJ, max = +150°C 6. Ratings apply to ambient temperature at +25°C. Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Symbol VKA IKA TA Parameter Cathode Voltage Cathode Current Operating Ambient Temperature Min Max Unit VREF 0.065 -40 36 100 +125 V mA °C Electrical Characteristics (@TA = +25°C, unless otherwise specified.) Symbol VREF VDEV ∆VREF ∆VKA IREF ∆IREF IKA(MIN) IKA(OFF) Parameter Test Conditions ZXRE250A Reference Voltage ZXRE250B TA = 0 to +70°C Deviation of Reference Voltage Over Full VKA = VREF, TA = -40 to +85°C Temperature Range (Note 7) IKA = 10mA TA = -40 to +125°C Ratio of the Change in Reference VKA = 10V to VREF Voltage to the Change in Cathode IKA = 10mA VKA = 36V to 10V Voltage VKA = VREF, IKA = 10mA Reference Input Current IKA = 10mA, R1 = 10KΩ, R2 = ∞ TA = 0 to +70°C IREF Deviation Over Full Temperature IKA = 10mA, R1 = TA = -40 to +85°C Range (Note 7) 10KΩ, R2 = ∞ TA = -40 to +125°C Minimum Cathode Current for Regulation VKA = VREF Off-State Current VKA = 36V, VREF = 0V |ZKA| Dynamic Output Impedance (Note 8) θJA SOT23 Thermal Resistance Junction to Ambient SOT25 Notes: VKA = VREF, f = 0Hz 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 - 1 0.8 0.8 0.8 40 0.05 4 1.2 2.5 2.5 65 0.5 µA µA µA µA µA µA - 0.2 0.5 Ω - 380 250 - °C/W °C/W 7. Deviation of VDEV, and ∆IREF are defined as the maximum variation of the values over the full temperature range. 8. Derivation of ZKA on following page. ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 2 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Electrical Characteristics (cont.) (@TA = +25°C, unless otherwise specified.) The average temperature coefficient of the reference input voltage αVREF is defined as: Vmax VDEV αVREF = X 106 VREF @ 25ºC ppm/ºC T2 – T1 Vmin Where: T2 – T1 = full temperature change. VDEV = Vmax - Vmin VREF can be positive or negative depending on whether the slope is α positive or negative. Note: 8. The dynamic output impedance, RZ, is defined as: ZKA = ∆VKA ∆IKA 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’ = ∆V ∆I ≈ ZKA 1+ R1 R2 Test Circuits Figure 2 Test Circuit for VKA > VREF Figure 1 Test Circuit for VKA = VREF Figure 3 Test Circuit for IOFF ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 3 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Typical Performance Characteristics 0.2 2600 IKA = 10mA R1 = 10KΩ R2 = ∞ IKA = 10mA V KA = VREF TA = 25 °C 2560 IREF Reference Current ( µA) V REF Reference Voltage (mV) 2580 2540 2520 2500 2480 2460 0.15 0.1 0.05 2440 2420 0 -55 2400 -55 -35 -15 5 25 45 65 85 105 125 TA Free Air Temperature ( °C) Reference Voltage vs. Free Air Temperature 150 -35 -15 5 25 45 65 85 105 125 TA Free Air Temperature ( °C) Reference Current vs. Free Air Temperature 200 V KA = VREF V KA = VREF TA = 25 °C TA = 25 °C IKA Cathode Current ( µA) IKA Cathode Current (mA) 100 50 0 100 IKMIN 0 -50 -100 -2 -1 0 1 2 V KA Cathode Voltage (V) C athode Current vs. C athode Voltage 3 -100 -2 0 1 2 V KA Cathode Voltage Cathode Current vs. C athode Voltage 3 -0.2 0.50 V KA = 36V 0.45 V KA = 3V t o 36V V REF = 0 -0.3 0.40 -0.4 0.35 dV REF/dV KA (mV/V) IKOFF Off-State Cathode Current ( µ A) -1 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 -1.0 -50 75 -25 0 25 50 100 125 TA Free Air Temperature (°C) Off-State Cathode Current vs. Free Air Temperature -50 ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 4 of 12 www.diodes.com 75 0 25 50 100 125 TA Free Air Temperature (C) R atio of Delta Reference Voltage to Delta Cathode Voltage vs. Free Air Temperature -25 February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Typical Performance Characteristics (cont.) 15 IKA = 10mA 380 IKA = 10mA V KA = VREF Vn - Equivalent Input Noise Voltage - µ V V N = Equivalent Input Noise Voltage nV/√Hz 400 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 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. 5 - 2 5 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Typical Performance Characteristics (cont.) A V Small-Signal Voltage Amplification (dB) 70 IKA = 10mA TA = 25 °C 60 50 40 30 20 10 Test Circuit for Voltage Amplification 0 100 10M 10K 100K 1M f Frequency (Hz) Small-Signal Voltage Amplification vs. Frequency 1K 100.0 IKA = 10mA ZKA Reference Impedance (Ω ) TA = 25 °C 10.0 1.0 0.1 0.0 1K Test Circuit for Reference Impedance 100K 1M f Frequency (Hz) R eference Impedance vs. Frequency 10K ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 10M 6 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Typical Performance Characteristics (cont.) 6 TA = 25 °C Input Input and Output Voltage (V) 5 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 IKA - Cathode Current - mA 80 TA = 25 °C D D 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 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. 5 - 2 7 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Application Information V+ V+ VOUT VOUT R1 R1 VREF VREF R2 R2 VOUT = (1 + R1 R2 ) VREF VOUT = (1 + R1 R2 ) VREF Higher Current Shunt Regulator Shunt Regulator V+ ZSR*** V+ Out In Common VOUT 30Ω R1 0.01µF Rb VREF R1 R2 VOUT VREF R2 VOUT(min) = VREF + VREG VOUT = (1 + R1 R2 ) VREF VOUT = (1 + R1 R2 ) VREF Rb - Optional to provide minimum cathode current Output Control of a Three Terminal Fixed Regulator Series Regulator V+ R1B V+ R1A Output VREF VON ~ ~ 2V VOFF = V+ R2A VREF Output Input VTH= 2.5V R2B R1B Low Limit= (1 + R2B ) VREF R1A High Limit = (1 + R2A ) VREF Single Supply Comparator with Temperature Compensated Threshold ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 Over Voltage / Under Voltage Protection Circuit 8 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Ordering Information Part Number (Note 9) Package Code Packaging ZXRE250A(B)SA-7 ZXRE250A(B)W5-7 ZXRE252A(B)SA-7 SA W5 SA SOT23 SOT25 SOT23 Note: 7” Tape and Reel Quantity Part Number Suffix 3,000/Tape & Reel -7 3,000/Tape & Reel -7 3,000/Tape & Reel -7 Quantity NA NA NA Ammo Box Part Number Suffix NA NA NA 9. Suffix (B) denotes ZXRE250B (0.5% tolerance) device. Marking Information (1) SOT23 ( Top View ) 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 XX Y W X 1 2 Device ZXRE250ASA ZXRE250BSA ZXRE252ASA ZXRE252BSA (2) Package SOT23 SOT23 SOT23 SOT23 Identification Code DA DB FA FB SOT25 ( Top View ) 4 7 5 XX Y W X 1 ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 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 9 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Package Outline Dimensions (All dimensions in mm.) Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for the latest version. (1) Package type: SOT25 A SOT25 Dim Min Max Typ A 0.35 0.50 0.38 B 1.50 1.70 1.60 C 2.70 3.00 2.80 D 0.95 H 2.90 3.10 3.00 J 0.013 0.10 0.05 K 1.00 1.30 1.10 L 0.35 0.55 0.40 M 0.10 0.20 0.15 N 0.70 0.80 0.75 0° 8° α All Dimensions in mm B C H K J (2) M N L D Package Types: SOT23 All 7° H K1 GAUGE PLANE 0.25 J K a M A L C L1 B D F SOT23 Dim Min Max Typ A 0.37 0.51 0.40 B 1.20 1.40 1.30 C 2.30 2.50 2.40 D 0.89 1.03 0.915 F 0.45 0.60 0.535 G 1.78 2.05 1.83 H 2.80 3.00 2.90 J 0.013 0.10 0.05 K 0.890 1.00 0.975 K1 0.903 1.10 1.025 L 0.45 0.61 0.55 L1 0.25 0.55 0.40 M 0.085 0.150 0.110 a 8° All Dimensions in mm G ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 10 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 Suggested Pad Layout Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version. (1) Package type: SOT25 C2 Z C2 Dimensions Value (in mm) Z 3.20 G 1.60 X 0.55 Y 0.80 C1 G C1 C2 Y 2.40 0.95 X (2) Package Types: SOT23 Y Z C X ZXRE250/ ZXRE252 Document number: DS35228 Rev. 5 - 2 Dimensions Value (in mm) Z 2.9 X 0.8 Y 0.9 C 2.0 E 1.35 E 11 of 12 www.diodes.com February 2015 © Diodes Incorporated ZXRE250/ ZXRE252 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). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. 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LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. 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