Bay Linear Inspire the Linear Power LM317 3-Terminal 1.5Amp Adjustable Voltage Regulator Description Features The Bay Linear LM317 are monolithic integrated circuit in TO- 220, TO-252, SOT-223 and D2PAK packages intended for use as positive adjustable voltage regulators. They are designed to supply more than 1.5A of load current with an output voltage adjustable over a 1.2 to 37V range. The nominal output voltage is selected by means of only a resistive divider, making the device exceptionally easy to use and eliminating the stocking of many fixed regulators. * * * * * * * * Output Current of 1.5A Output Voltage Tolerance of 5% Adjustable Output 1.2V to 37V 0.1% Load & Line Regulation Internal Short-Circuit Limited Current Limit Offer in plastic TO-252, TO-220, SOT-223 & TO-263 Direct Replacement for LM317 Applications * * Packaging Information Post regulator for switching DC/DC converter Bias supply for analog circuits Ordering Information Device Package Type Output LM317T LM317N LM317S LM317D TO-220 SOT-223 TO-263 TO-252 1.5 Amp 1.0 Amp 1.5 Amp 1.5 Amp TO-263-3 (S) ( Bay Linear 1 2 3 1. ADJ 2. Output 3. Input SOT-223 Vs. TO-252 Package Top View Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com LM317 Absolute Maximum Rating Parameter LM317 Power Dissipation Input Voltage Differential Operating Free-Air, Case, Virtual Junction Temp. Storage Temperature Range Lead temperature 1.6 mm from case for sec. Unit Internally Limited +40V, -0.3V 0 to 150 -65 to 150 260 V C Electrical Characteristics (LM317) Parameter Reference Voltage Symbol Conditions Line Regulation VO 3V(VIN-VOUT) 40V 10mAIOUTIMAX, PPMAX 3V(VIN-VOUT) 40V (Note 4) Load Regulation VO 10mAIOUT IMAX (Note 4) Ripple Rejection RR VI = 10V,, f=120Hz CADJ=0F VI = 10V,, f=120Hz CADJ=10F 20ms Thermal Regulation Adjustment Pin Current Adjustment Pin Current Change Temperature Stability Long Term Stability RMS Output Noise % of VOUT Minimum Load Current Maximum Load Current Bay Linear, Inc VO MIN TYP MAX UNIT 1.20 1.25 1.30 V 0.01 0.02 0.1 0.3 65 0.02 0.05 0.3 1 %/V 66 10mAIOUTIMAX, 3V(VIN-VOUT) 40V TMINTJTMAX TJ=125C, 1000 hrs 10Hzf10KHz 80 dB 0.03 50 0.07 100 %W A 0.2 5 A 1 0.3 0.003 1 % % % 3.5 5 mA (VIN-VOUT) =40V (VIN-VOUT) 15V PDPMAX (VIN-VOUT) 40V PDPMAX % % dB 1.5 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 2.2 A 0.4 A www.baylinear.com LM317 Application Notes: The LM317 provides an internal reference voltage of 1.25V between the output and adjustments terminals. This is used to set a constant current flow across an external resistor divider show below, giving an output voltage VO of: VO = VREF ( 1 + R 2 R 1 ) + IADJ R2 The device was designed to minimize the term IADJ ( 100 m A max) and to maintain it very constant with line and load changes. Usually, the error term IADJ V R2 can be neglected. To obtain the previous requirement, all the regulator quiescent current is returned to the output terminal, imposing a minimum load current condition. If the load is insufficient, the output voltage will rise. Since the LM317 is a floating regulator and " sees" only the input- tooutput differential voltage, supplies of very high voltage with respect to ground can be regulated as long as the maximum input- to- output differential is not exceeded. Furthermore, programmable regulator are easily obtainable and, by connecting a fixed resistor between the adjustment and output, the device can be used as a precision current regulator. In order to optimise the load regulation, the current set resistor R1 show below should be tied as close as possible to the regulator, while the ground terminal of R2 should be near the ground of the load to provide remote ground sensing. Performance may be improved with added capacitance as follow: to improve the ripple rejection of about 15 dB ( CADJ). An 1F tantalium ( or 25 FAluminium electrolitic) capacitor on the output to improve transient response. In additional to external capacitors, it is good practice to add protection diodes, as shown in below. D1 protect the device against input short circuit, while D2 protect against output short circuit for capacitance discharging. An input bypass capacitor of 0.1F An adjustment terminal to ground 10F capacitor Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations, computer simulations and/ or initial prototype evaluation. Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges. The application circuit examples are only to explain the representative applications of the devices and are not intended to guarantee any circuit design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any industrial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different applications. Customer's technical experts must validate all operating parameters including " Typical" for each customer application. LIFE SUPPORT AND NUCLEAR POLICY Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without the specific written consent of Bay Linear President. Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com