SPX431A Precision Adjustable Shunt Regulator April 2009 Rev. 2.0.0 GENERAL DESCRIPTION APPLICATIONS The SPX431A is a three-terminal adjustable shunt voltage regulator providing a highly accurate bandgap reference. The SPX431A acts as an open-loop error amplifier with a 2.5V temperature compensation reference. The SPX431A has thermal stability, wide operating current of 150mA and broad temperature range of -40C to 125C, making it suitable for a variety of applications which require a low-cost, high performance solution. The SPX431A tolerance of 0.5% is proven to be sufficient to overcome all other errors in the system to virtually eliminate the need for trimming in the power supply manufacturer's assembly line and contribute a significant cost savings. The output voltage may be adjusted to any value between VREF and 36 volts with two external resistors. The SPX431A is available in RoHS compliant, lead free TO-92 and SOT89 packages. * Charger * Switching Power Supplies * Graphic Cards * Monitors, VCRs, TVs FEATURES * 0.5% Precise Output Voltage - Adjustable up to 36V * Wide Operating Current - 1mA to 150mA * Low Temperature Coefficient at 30ppm/C * Extended Temperature Range - -40C to +125C * Improved Replacment for TL431 * RoHS Compliant, Lead Free TO-92 and SOT-89 Packages TYPICAL APPLICATION DIAGRAM Fig. 1: SPX431A Application Diagram Exar Corporation 48720 Kato Road, Fremont CA 94538, USA www.exar.com Tel. +1 510 668-7000 - Fax. +1 510 668-7001 SPX431A Precision Adjustable Shunt Regulator ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Cathode-Anode Reverse Breakdown Volt. VKA ............. 36V Operating Cathode Current (cont.) IKA ................ <100mA Ambient Temperature Range ....................-40C to 125C Cathode-Anode Reverse Breakdown Volt. VKA ............. 37V Operating Cathode Current (cont.) IKA ................... 150mA Reference Input Current Range IREF .........................10mA Power Dissipation SOT-89-TO-92 (Cont. 25C) PD .. 770mW Junction Temperature .......................................... 150C Storage Temperature TSTG........................ -65C to 150C ESD Rating (HBM - Human Body Model) .................... 2kV ELECTRICAL SPECIFICATIONS Specifications with standard type are for an Operating Ambient Temperature of TA = 25C only; limits applying over the full Operating Ambient Temperature range are denoted by a "*". Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TA = 25C, and are provided for reference purposes only. Parameter Min. Typ. Max. Units 2.493 2.503 2.515 V VREF with temperature TC 4.5 8 mV VREF with temperature TC 4.5 16 mV Reference Voltage Ratio of change in VREF to Cathode Voltage VREF / VKA -2.7 -1.0 -2 -0.4 Conditions Test circuit 1 VKA=VREF, IKA=10mA Test circuit 1 VKA=VREF, IKA=10mA, 0C TA 70C * Test circuit 1 VKA=VREF, IKA=10mA Test circuit 2 VREF VKA 10V, IKA=10mA mV/V Test circuit 2 10V VKA 36V, IKA=10mA Test circuit 2 IKA=10mA, R1=10k, R2= Reference Input Current IREF 0.7 4 A IREF Temperature Deviation IREF 0.4 1.2 A Minimum IKA for Regulation IKA(MIN) 0.4 1 mA Test circuit 1 VKA=VREF Off State Leakage IKA(OFF) 40 250 nA Test circuit 3 VKA=0, VREF=36V 0.15 0.5 Test circuit 1 fZ1KHz, IKA=1 to 100mA Dynamic Outout Impedance ZKA (c) 2009 Exar Corporation 2/11 * Test circuit 2 IKA=10mA, R1=10k, R2= Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator BLOCK DIAGRAM Fig. 2: SPX431A Block Diagram PIN ASSIGNEMENT 3-pin SOT89 (M1) 3-pin TO-92 (N) Fig. 3: SPX431A Pin Assignement ORDERING INFORMATION Part Number Temperature Range Marking Package Packing Quantity Note 1 SPX431AM1-L/TR -40CTA+125C SOT89 2.5K/Tape & Reel RoHS Compliant Lead Free SPX431AN-L/TR -40CTA+125C TO-92 2K/Tape & Reel RoHS Compliant Lead Free Note 2 Ammo Pack "YY" = Year - "WW" = Work Week - "X" = Lot Number (c) 2009 Exar Corporation 3/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator TYPICAL PERFORMANCE CHARACTERISTICS All data taken at TA = 25C, unless otherwise specified - Schematic and BOM from Application Information section of this datasheet. Fig. 4: Cathode Current vs Cathode Voltage Fig. 5: Reference Voltage vs Ambient Temperature Fig. 6: Low Current Operating Characteristics Fig. 7: Reference Input Current vs Ambient Temperature Fig. 8: Reference Voltage to Cathode Voltage Ratio (c) 2009 Exar Corporation 4/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator Fig. 9: Test Circuit for Gain vs Frequency Responce Fig. 10: Small Signal Gain vs Frequency Fig. 11: Test Circuit for Pulse Response Fig. 12: Pulse Response Fig. 13: Test Circuit for Stability Fig. 14: Stability Boundary Conditions (c) 2009 Exar Corporation 5/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator Fig. 15: Test Circuit for Dynamic Output Impedance Fig. 16: Dynamic Output Impedance Fig. 17: Off State Leakage (c) 2009 Exar Corporation 6/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator TYPICAL APPLICATION SCHEMATICS Fig. 18: Shunt Regulator VOUT=(1+R1/R2)VREF Fig. 19: Constant Current Sink ISINK=VREF/R1 Fig. 20: Reference Amplifier for Isolated Feedback in Offline DC-DC Coinverters Fig. 21: Precision High Current Series Regulator VOUT=(1+R1/R2)VREF Fig. 22: High Current Shunt Regulator VOUT=(1+R1/R2)VREF Fig. 23: Single Supply Comparator with Temperature Compensated Threshold (c) 2009 Exar Corporation 7/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator TEST CIRCUITS TEST CIRCUIT 1 Test circuit for VKA=VREF TEST CIRCUIT 2 Test circuit for VKA > VREF TEST CIRCUIT 3 Test circuit for IKOFF (c) 2009 Exar Corporation 8/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator PACKAGE SPECIFICATION SOT-89 Unit: mm (inch) (c) 2009 Exar Corporation 9/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator TO-92 Unit: mm (inch) (c) 2009 Exar Corporation 10/11 Rev. 2.0.0 SPX431A Precision Adjustable Shunt Regulator REVISION HISTORY Revision 2.0.0 Date 04/15/09 Description Reformat of Datasheet Updated ordering part numbers Updated application and block diagram FOR FURTHER ASSISTANCE Email: customersupport@exar.com Exar Technical Documentation: http://www.exar.com/TechDoc/default.aspx? EXAR CORPORATION HEADQUARTERS AND SALES OFFICES 48720 Kato Road Fremont, CA 94538 - USA Tel.: +1 (510) 668-7000 Fax: +1 (510) 668-7030 www.exar.com NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. or its in all Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. (c) 2009 Exar Corporation 11/11 Rev. 2.0.0