AN431

Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS General Description The AN431 series ICs are three-terminal adjustable shunt regulators with guaranteed thermal stability over a full operation range. These ICs feature sharp turn-on characteristics, low temperature coefficient and low output impedance, which make them ideal substitutes for Zener diodes in applications such as switching power supply, charger and other adjustable regulators. The output voltage of these ICs can be set to any value between VREF (2.5V) and the maximum cathode voltage (36V). The AN431 precision reference is offered in two voltage tolerance: 0.5% and 1.0%. These ICs are available in SOT-23 package. AN431 Features · · · · · · · · Programmable Precise Output Voltage from 2.5V to 36V High Stability under Capacitive Load Low Temperature Deviation: 4.5mV Typical Low Equivalent Full-range Temperature Coefficient with 20PPM/oC Typical Low Dynamic Output Resistance: 0.15Ω Typical Sink Current Capacity from 1mA to 100mA Low Output Noise Wide Operating Range of -40 to 125oC Applications · · · · · Charger Voltage Adapter Switching Power Supply Graphic Card Precision Voltage Reference SOT-23 Figure 1. Package Type of AN431 Mar. 2007 Rev. 1. 7 1 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Pin Configuration N Package (SOT-23) ANODE AN431 3 1 2 CATHODE REF Figure 2. Pin Configuration of AN431 (Top View) Functional Block Diagram CATHODE 1 REF 2 + - VREF 3 ANODE Figure 3. Functional Block Diagram of AN431 Mar. 2007 Rev. 1. 7 2 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Ordering Information AN431 AN431 Circuit Type Voltage Tolerance A: 0.5% B: 1.0% Package E1: Lead-Free TR: Tape and Reel A: AN431 (40V) N: SOT-23 Package SOT-23 Temperature Range -40 to 125oC Voltage Tolerance 0.5% 1.0% Part Number AN431AN-ATRE1 AN431BN-ATRE1 Marking ID EB1 EB2 Packing Type Tape & Reel Tape & Reel BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Mar. 2007 Rev. 1. 7 3 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Absolute Maximum Ratings (Note 1) Parameter Cathode Voltage Cathode Current Range (Continuous) Reference Input Current Range Power Dissipation Junction Temperature Storage Temperature Range ESD (Human Body Model) Symbol VKA IKA IREF PD TJ TSTG ESD Value 40 -100 to 150 10 370 150 -65 to 150 2000 Unit V mA mA mW oC oC AN431 V Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods may affect device reliability. Recommended Operating Conditions Parameter Cathode Voltage Cathode Current Operating Ambient Temperature Range Symbol VKA IKA Min VREF 1.0 -40 Max 36 100 125 Unit V mA oC Mar. 2007 Rev. 1. 7 4 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Electrical Characteristics Operating Conditions: TA=25oC, unless otherwise specified. Parameter Reference Voltage 0.5% 1.0% Test Circuit 4 Symbol VREF Conditions VKA=VREF, IKA=10mA 0 to 70oC Deviation of Reference Voltage Over Full Temperature Range 4 ∆VREF VKA=VREF IKA=10mA -40 to 85oC -40 to 125oC Ratio of Change in Reference Voltage to the Change in Cathode Voltage Reference Current Deviation of Reference Current Over Full Temperature Range Minimum Cathode Current for Regulation Off-state Cathode Current ∆VREF ∆VKA IREF ∆IREF IKA (Min) IKA (Off) ZKA ∆VKA= 10V to VREF ∆VKA= 36V to 10V Min 2.487 2.475 Typ 2.500 2.500 4.5 4.5 4.5 -1.0 -0.5 0.7 0.4 Max 2.512 2.525 8 10 16 -2.7 mV/V -2.0 4 1.2 µA µA mV Unit V AN431 5 IKA=10mA 5 5 IKA=10mA, R1=10KΩ, R2=∞ IKA=10mA, R1=10KΩ R2=∞, TA=-40 to 125oC VKA=VREF VKA=36V, VREF=0 VKA=VREF, IKA=1 to 100mA, f ≤ 1.0kHz 4 0.4 1.0 mA µA Ω 6 0.05 1.0 Dynamic Impedance 4 0.15 0.5 Mar. 2007 Rev. 1. 7 5 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Electrical Characteristics (Continued) AN431 R1 VIN IKA VKA VREF Figure 4. Test Circuit 4 for VKA=VREF R3 VIN IKA R1 IREF VKA=VREF*(1+R1/R2)+ IREF*R1 VREF VKA R2 Figure 5. Test Circuit 5 for VKA>VREF VIN IOFF VKA Figure 6. Test Circuit 6 for IOFF Mar. 2007 Rev. 1. 7 6 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Performance Characteristics AN431 2.510 VKA=VREF 2.505 Reference Voltage (V) IKA=10mA 1.5 R1=10K,R2= ∞ IKA=10mA Reference Current (µA) 1.0 2.500 2.495 0.5 2.490 2.485 -60 -40 -20 0 20 40 60 o 80 100 120 140 0.0 -60 -40 -20 0 20 40 60 80 0 100 120 140 Ambient Temperature ( C) Ambient Temperature ( C) Figure 7. Reference Voltage vs. Ambient Temperature Figure 8. Reference Current vs. Ambient Temperature 150 VKA=VREF TA=25 C 0 800 600 Cathode Current (µA) 400 200 0 -200 VKA=VREF TA=25 C 0 Cathode Current (mA) 100 50 0 -50 -100 -2 -1 0 1 2 3 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 Cathode Voltage (V) Cathode Voltage (V) Figure 9. Cathode Current vs. Cathode Voltage Figure 10. Cathode Current vs. Cathode Voltage Mar. 2007 Rev. 1. 7 7 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Performance Characteristics (Continued) AN431 2.0 1.8 VKA=36V VREF=0 -0.9 VKA=3.5V to 36V Off-state Cathode Current (µA) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -40 -1.0 ∆VREF / ∆VKA (mV/V) -1.1 -1.2 -1.3 -1.4 -20 0 20 40 60 o 80 100 120 -40 -20 0 20 40 60 o 80 100 120 Ambient Temperature ( C) Ambient Temperature ( C) Figure 11. Off-state Cathode Current vs. Ambient Temperature Figure 12. Ratio of Delta Reference Voltage to the Ratio of Delta Cathode Voltage 70 60 50 Output TA=25 C IKA=10mA 0 15K 10µF I KA 242 Voltage Gain (dB) 40 30 20 10 0 -10 1k 8.2K 10k 100k 1M GND Small Signal Frequency (Hz) Figure 13. Small Signal Voltage Gain vs. Frequency Mar. 2007 Rev. 1. 7 8 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Performance Characteristics (Continued) AN431 Output IKA=10mA Reference Impedance (Ω) 10 1K IKA 50 TA=25 C o 1 GND 0.1 1K 10K 100K 1,000K Frequency (Hz) Figure 14. Reference Impedance vs. Frequency 100 90 80 VKA=VREF VKA= 5V VKA=10V VKA=15V Stable Stable R1 (10K) IKA 150 Cathode Current (mA) 70 60 50 40 30 20 10 0 0.001 R2 0.01 0.1 1 10 Load Capacitance (µF) Figure 15. Stability Boundary Conditions vs. Load Capacitance Mar. 2007 Rev. 1. 7 9 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Performance Characteristics (Continued) AN431 5 Input Input and Output Voltage (V) 4 Output 220 3 2 Output Pulse Generator f=100KHz 50 1 GND 0 0 2 4 6 Time (µS) Figure 16. Pulse Response of Input and Output Voltage Mar. 2007 Rev. 1. 7 10 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Application R3 VIN R1 V OUT AN431 VOUT=(1+R1/R2)*VREF V REF R2 AN431 Figure 17. Shunt Regulator VIN R1 R4 R2 VREF VOUT VOUT=(1+R2/R3)*VREF AN431 R3 Figure 18. High Current Shunt Regulator R2 V IN I OUT R1 IOUT=VREF/R2 + IKA AN431 Figure 19. Current Source or Current Limit Mar. 2007 Rev. 1. 7 11 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Typical Application (Continued) AN431 VIN R1 8.2K AZ1117 Adjust R2 250 AN431 R3 250 VOUT 5V, 1A Figure 20. Precision 5V 1A Regulator C1 R2 680 R5 R1 3 R3 R4 VOUT U2 C2 Q1 2 AN431 COMP PWM Controller VFB 4 PS521 Figure 21. PWM Converter with Reference Mar. 2007 Rev. 1. 7 12 BCD Semiconductor Manufacturing Limited Data Sheet ADJUSTABLE PRECISION SHUNT REGULATORS Mechanical Dimensions SOT-23 Unit: mm(inch) AN431 Mar. 2007 Rev. 1. 7 13 BCD Semiconductor Manufacturing Limited http://www.bcdsemi.com IMPORTANT NOTICE BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifications herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or other rights nor the rights of others. MAIN SITE BCD Semiconductor Manufacturing Limited - Wafer Fab Shanghai SIM-BCD Semiconductor Manufacturing Limited 800, Yi Shan Road, Shanghai 200233, China Tel: +86-21-6485 1491, Fax: +86-21-5450 0008 BCD Semiconductor Manufacturing Limited - IC Design Group Advanced Analog Circuits (Shanghai) Corporation 8F, Zone B, 900, Yi Shan Road, Shanghai 200233, China Tel: +86-21-6495 9539, Fax: +86-21-6485 9673 REGIONAL SALES OFFICE Shenzhen Office Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd. 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