SSPPXX33994400 11AA LLooww DDrrooppoouutt VVoollttaaggee RReegguullaattoorr February 2012 Rev. 1.0.0 GENERAL DESCRIPTION APPLICATIONS The SPX3940 is a 1A, accurate voltage Power Supplies regulator with a low drop out voltage of LCD Monitors 280mV (typical) at 1A. Portable Instrumentation These regulators are specifically designed for low voltage applications that require a low Medical and Industrial Equipments dropout voltage and a fast transient response. They are fully fault protected against over- FEATURES current, reverse battery, and positive and negative voltage transients. Guaranteed 1.5A Peak Current The SPX3940 is offered in 3-pin SOT223 and 1% Output Accuracy SPX3940A TO-263 packages. For a 3A version, refer to Low Quiescent Current the SPX29300 data sheet. Low Dropout Voltage of 280mV at 1A Extremely Tight Load and Line Regulation Extremely Fast Transient Response Reverse-battery Protection Internal Thermal Protection Internal Short Circuit Current Limit Replacement for LM3940 Standard SOT223 & TO-263 packages TYPICAL APPLICATION DIAGRAM Fig. 1: SPX3940 Application Diagram Fixed Output Linear Regulator Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 SSPPXX33994400 11AA LLooww DDrrooppoouutt VVoollttaaggee RReegguullaattoorr ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS These are stress ratings only and functional operation of Input Voltage V .................................................... 16V IN the device at these ratings or any other above those Junction Temperature Range ....................-40C to 125C indicated in the operation sections of the specifications Packages Thermal Resistance below is not implied. Exposure to absolute maximum SOT-223 Junction to Case (at T ) ..................... 15C/W A rating conditions for extended periods of time may affect SOT-223 Junction to Ambient ........................62.3C/W reliability. TO-263 Junction to Case (at T ) ......................... 3C/W A 1 Input Voltage V ................................................... 20V IN TO-263 Junction to Ambient ..........................31.4C/W Storage Temperature .............................. -65C to 150C Lead Temperature (Soldering, 5 sec) ..................... 260C Note 1: Maximum positive supply voltage of 20V must be of limited duration (<100ms) and duty cycle (<1%). The maximum continuous supply voltage is 16V. ELECTRICAL SPECIFICATIONS Specifications with standard type are for an Operating Ambient Temperature of T = 25C only limits applying over the full A Operating Junction 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 T = 25C, and are provided A for reference purposes only. Unless otherwise indicated, V = V +1V, I = 10mA, C = 6.8F, C = 10F, T = 25C. IN IN OUT IN OUT A Parameter Min. Typ. Max. Units Conditions 1.8V version 1.8 1.818 1.782 Output Voltage - SPX3940A (1%) V 1.8 1.845 1.755 I =10mA OUT 10mAI 1A, 6VV 16V 1.764 1.8 1.836 OUT IN Output Voltage - SPX3940 (2%) V 1.737 1.8 1.863 2.5V version 2.5 2.525 2.475 Output Voltage - SPX3940A (1%) V 2.437 2.5 2.563 I =10mA OUT 10mAI 1A, 6VV 16V 2.450 2.5 2.550 OUT IN Output Voltage - SPX3940 (2%) V 2.412 2.5 2.588 3.3V version 3.3 3.333 3.267 Output Voltage - SPX3940A (1%) V 3.217 3.3 3.383 I =10mA OUT 10mAI 1A, 6VV 16V 3.234 3.3 3.366 OUT IN Output Voltage - SPX3940 (2%) V 3.184 3.3 3.416 5.0V version 4.950 5.0 5.050 Output Voltage - SPX3940A (1%) V 4.875 5.0 5.125 IOUT=10mA 10mAI 1A, 6VV 16V 4.900 5.0 5.100 OUT IN Output Voltage - SPX3940 (2%) V 5.0 5.175 4.825 All Voltage Options Line Regulation 0.2 1.0 % I =10mA, (V +1V)V 16V OUT OUT IN Load Regulation 0.3 1.5 % V = V +1V,10mAI 1A IN OUT OUT - Output Voltage 20 100 ppm/C temperature Coefficient 2 70 200 mV I =100mA OUT Dropout Voltage (except 1.8V version) 280 550 mV I =1A OUT 12 25 mA I =750mA, V = V +1V OUT IN OUT 3 Ground Current 18 mA I =1A OUT I Ground Pin Current at GNDDO 1.2 mA V = 0.1V less than specified V I =10mA, IN OUT OUT Dropout 4 Current Limit 2.2 A V = 0V 1.5 OUT 10Hz-100KHz, I =100mA, C =10F 400 V L L RMS Output Noise Voltage 260 V 10Hz-100KHz, I =100mA, C =33F RMS L L 2012 Exar Corporation 2/11 Rev. 1.0.0