0
登录后你可以
  • 下载海量资料
  • 学习在线课程
  • 观看技术视频
  • 写文章/发帖/加入社区
会员中心
创作中心
发布
  • 发文章

  • 发资料

  • 发帖

  • 提问

  • 发视频

创作活动
LM317KCE3

LM317KCE3

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    TO-220-3

  • 描述:

    IC REG LIN POS ADJ 1.5A TO220-3

  • 数据手册
  • 价格&库存
LM317KCE3 数据手册
Product Folder Order Now Support & Community Tools & Software Technical Documents LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 LM317 3-Terminal Adjustable Regulator 1 Features 3 Description • The LM317 device is an adjustable three-terminal positive-voltage regulator capable of supplying more than 1.5 A over an output-voltage range of 1.25 V to 37 V. It requires only two external resistors to set the output voltage. The device features a typical line regulation of 0.01% and typical load regulation of 0.1%. It includes current limiting, thermal overload protection, and safe operating area protection. Overload protection remains functional even if the ADJUST terminal is disconnected. 1 • • • • Output voltage range adjustable from 1.25 V to 37 V Output current greater than 1.5 A Internal short-circuit current limiting Thermal overload protection Output safe-area compensation 2 Applications • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ATCA solutions DLP: 3D biometrics, hyperspectral imaging, optical networking, and spectroscopy DVR and DVS Desktop PCs Digital signage and still cameras ECG electrocardiograms EV HEV chargers: levels 1, 2, and 3 Electronic shelf labels Energy harvesting Ethernet switches Femto base stations Fingerprint and iris biometrics HVAC: heating, ventilating, and air conditioning High-speed data acquisition and generation Hydraulic valves IP phones: wired and wireless Intelligent occupancy sensing Motor controls: brushed DC, brushless DC, lowvoltage, permanent magnet, and stepper motors Point-to-point microwave backhauls Power bank solutions Power line communication modems Power over ethernet (PoE) Power quality meters Power substation controls Private branch exchanges (PBX) Programmable logic controllers RFID readers Refrigerators Signal or waveform generators Software-defined radios (SDR) Washing machines: high-end and low-end X-rays: baggage scanners, medical, and dental Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) LM317DCY SOT-223 (4) 6.50 mm × 3.50 mm LM317KCS TO-220 (3) 10.16 mm × 9.15 mm LM317KCT TO-220 (3) 10.16 mm × 8.59 mm LM317KTT TO-263 (3) 10.16 mm × 9.01 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Battery-Charger Circuit LM317 VI INPUT RS 0.2 W OUTPUT ADJUST R1 240 W R2 2.4 kW 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com Table of Contents 1 2 3 4 5 6 7 8 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Device Comparison Table..................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 5 7.1 7.2 7.3 7.4 7.5 7.6 5 5 5 5 6 7 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Typical Characteristics .............................................. Detailed Description .............................................. 9 8.1 Overview ................................................................... 9 8.2 Functional Block Diagram ......................................... 9 8.3 Feature Description................................................... 9 8.4 Device Functional Modes........................................ 10 9 Application and Implementation ........................ 11 9.1 Application Information............................................ 11 9.2 Typical Application .................................................. 11 9.3 System Examples ................................................... 12 10 Power Supply Recommendations ..................... 18 11 Layout................................................................... 18 11.1 Layout Guidelines ................................................. 18 11.2 Layout Example .................................................... 18 12 Device and Documentation Support ................. 19 12.1 12.2 12.3 12.4 12.5 Receiving Notification of Documentation Updates Support Resources ............................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 19 19 19 19 19 13 Mechanical, Packaging, and Orderable Information ........................................................... 19 4 Revision History Changes from Revision X (September 2016) to Revision Y Page • Added Device Comparison Table .......................................................................................................................................... 3 • Changed VIN to IOUT in Load Transient Response figures ...................................................................................................... 7 • Added missing caption to second y-axis in second Load Transient Response figure ........................................................... 7 • Changed VOUT and output impedance equations in Battery-Charger Circuit section........................................................... 14 Changes from Revision W (January 2015) to Revision X Page • Changed body size dimensions for KCS TO-220 Package on Device information table ...................................................... 1 • Changed body size dimensions for KTT TO-263 Package on Device information table ...................................................... 1 • Changed VO Output Voltage max value from 7 to 37 on Recommended Operating Conditions table .................................. 5 • Added min value to IO Output Current in Recommended Operating Conditions table .......................................................... 5 • Changed values in the Thermal Information table to align with JEDEC standards ............................................................... 5 • Added KCT package data to Thermal Information table ....................................................................................................... 5 • Deleted Section 9.3.6 "Adjusting Multiple On-Card Regulators with a Single Control" ....................................................... 14 • Updated Adjustsable 4-A Regulator Circuit graphic ............................................................................................................ 16 • Added Receiving Notification of Documentation Updates section and Community Resources section .............................. 19 Changes from Revision V (February 2013) to Revision W Page • Added Applications, Device Information table, Pin Functions table, ESD Ratings table, Thermal Information table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ..................................................................................................................... 1 • Deleted Ordering Information table. ....................................................................................................................................... 1 2 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 5 Device Comparison Table IOUT 1.5 A PARAMETER LM317 LM317-N LM317A LM317HV Input voltage range 4.25 - 40 4.25 - 40 4.25 - 40 4.25 - 60 UNIT V Load regulation accuracy 1.5 1.5 1 1.5 % dB PSRR (120 Hz) 64 80 80 65 Recommended operating temperature 0 to 125 0 to 125 –40 to 125 0 to 125 °C TO-220 (NDE) TJA 23.5 23.2 23.3 23 °C/W TO-200 (KCT) TJA 37.9 N/A N/A °C/W TO-252 TJA N/A 54 54 °C/W TO-263 TJA 38 41 N/A °C/W SOT-223 TJA 66.8 59.6 59.6 °C/W N/A 186 186 °C/W TO-92 TJA LM317M 0.5 A Input voltage range 3.75 - 40 Load regulation accuracy 1.5 % PSRR (120 Hz) 80 dB Recommended operating temperature -40 - 125 °C SOT-223 TJA 60.2 °C/W TO-252 TJA 56.9 °C/W LM317L LM317L-N 3.75 - 40 4.25 - 40 Load regulation accuracy 1 1.5 % PSRR (120 Hz) 62 80 dB Recommended operating temperature –40 to 125 –40 to 125 °C SOT-23 TJA 167.8 N/A °C/W SO-8 TJA N/A 165 °C/W DSBGA TJA N/A 290 °C/W TO-92 TJA N/A 180 °C/W Input voltage range 0.1 A V V Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 3 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com 6 Pin Configuration and Functions DCY Package 3-Pin SOT-223 Top View 1 OUTPUT 2 INPUT 3 4 OUTPUT ADJUST KCS or KCT Package 3-Pin TO-220 Top View OUTPUT 3 INPUT 2 OUTPUT 1 ADJUST Not to scale Not to scale OUTPUT KTT Package 3-Pin TO-263 Top View 3 INPUT 2 OUTPUT 1 ADJUST Not to scale Pin Functions PIN I/O DESCRIPTION TO-263, TO-220 SOT-223 ADJUST 1 1 I Output voltage adjustment pin. Connect to a resistor divider to set VO INPUT 3 3 I Supply input pin OUTPUT 2 2, 4 O Voltage output pin NAME 4 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 7 Specifications 7.1 Absolute Maximum Ratings over virtual junction temperature range (unless otherwise noted) (1) MIN VI – VO Input-to-output differential voltage TJ Tstg (1) MAX UNIT 40 V Operating virtual junction temperature 150 °C Lead temperature 1,6 mm (1/16 in) from case for 10 s 260 °C 150 °C Storage temperature –65 Stresses beyond 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-rated conditions for extended periods may affect device reliability. 7.2 ESD Ratings MAX V(ESD) (1) (2) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) 2500 Charged device model (CDM), per JEDEC specification JESD22-C101 (2) 1000 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 7.3 Recommended Operating Conditions VO Output voltage VI – VO Input-to-output differential voltage IO Output current TJ Operating virtual junction temperature MIN MAX 1.25 37 UNIT V V 3 40 0.01 1.5 A 0 125 °C 7.4 Thermal Information LM317 DCY (SOT-223) KCS (TO-220) KCT (TO-220) KTT (TO-263) 4 PINS 3 PINS 3 PINS 3 PINS 66.8 23.5 37.9 38.0 °C/W RθJC(top) Junction-to-case (top) thermal resistance 43.2 15.9 51.1 36.5 °C/W RθJB Junction-to-board thermal resistance 16.9 7.9 23.2 18.9 °C/W ψJT Junction-to-top characterization parameter 3.6 3.0 13.0 6.9 °C/W ψJB Junction-to-board characterization parameter 16.8 7.8 22.8 17.9 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance NA 0.1 4.2 1.1 °C/W THERMAL METRIC (1) Rθ(JA) (1) Junction-to-ambient thermal resistance UNIT For more information about traditional and new thermal metrics, see the Semiconductor and IC package thermal metrics application report. Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 5 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com 7.5 Electrical Characteristics over recommended ranges of operating virtual junction temperature (unless otherwise noted) TEST CONDITIONS (1) PARAMETER Line regulation (2) VI – VO = 3 V to 40 V CADJ (3) = 10 μF, TJ = 25°C Load regulation IO = 10 mA to 1500 mA TJ = 0°C to 125°C Thermal regulation 20-ms pulse, MIN TYP MAX TJ = 25°C 0.01 0.04 TJ = 0°C to 125°C 0.02 0.07 25 mV 0.1 0.5 %VO VO ≤ 5 V VO ≥ 5 V 20 70 mV VO ≥ 5 V 0.3 1.5 %VO 0.03 0.07 %VO/W 50 100 μA 0.2 5 μA 1.25 1.3 V TJ = 25°C Change in ADJUST terminal current VI – VO = 2.5 V to 40 V, PD ≤ 20 W, IO = 10 mA to 1500 mA Reference voltage VI – VO = 3 V to 40 V, PD ≤ 20 W, IO = 10 mA to 1500 mA Output-voltage temperature stability TJ = 0°C to 125°C 0.7 Minimum load current to maintain regulation VI – VO = 40 V 3.5 VI – VO ≤ 15 V, PD < PMAX (4) VI – VO ≤ 40 V, PD < PMAX (4), RMS output noise voltage f = 10 Hz to 10 kHz, (% of VO) Ripple rejection VO = 10 V, Long-term stability TJ = 25°C (1) (2) (3) (4) 6 1.2 TJ = 25°C 1.5 2.2 0.15 0.4 TJ = 25°C f = 120 Hz %/V VO ≤ 5 V ADJUST terminal current Maximum output current UNIT %VO 10 A 0.003 CADJ = 0 μF (3) %VO 57 CADJ = 10 μF (3) 62 dB 64 0.3 mA 1 %/1k hr Unless otherwise noted, the following test conditions apply: |VI – VO| = 5 V and IOMAX = 1.5 A, TJ = 0°C to 125°C. Pulse testing techniques are used to maintain the junction temperature as close to the ambient temperature as possible. Line regulation is expressed here as the percentage change in output voltage per 1-V change at the input. CADJ is connected between the ADJUST terminal and GND. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA) / θJA. Operating at the absolute maximum TJ of 150°C can affect reliability. Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 7.6 Typical Characteristics 1.4 10.01 TA = 25°C TA = –40°C 1.2 10.005 TA = –40°C 1 0.8 10 V OUT – V V OUT – V TA = 25°C 9.995 TA = 125°C 0.6 0.4 TA = 125°C 0.2 9.99 0 9.985 -0.2 VOUT = VREF VOUT = 10 V Nom -0.4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 9.98 IOUT – A IOUT – A Figure 2. Load Regulation Figure 1. Load Regulation 0 -0.5 10.8 -0.5 -1 10.6 -1 10.4 -1.5 11 10.8 10 -3 9.8 -3.5 9.6 -4 -4.5 Load Current – A 10.2 10.4 -2 10.2 VOUT -2.5 10 -3 9.8 -3.5 9.6 9.4 -4 9.4 9.2 -4.5 Tim e – µs -68 1.28 -66 1.275 -64 V IN – V 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 V IN = 15 V V OUT = 10 V f = 120 Hz TA = 25°C 0.6 40 35 -50 30 1.24 25 -52 20 1.245 15 -54 10 1.25 5 70 -56 0.5 TA = 125°C -58 0.4 1.26 -60 0.3 TA = 25°C 0.2 1.265 -62 0 TA = –40°C 0.1 Ripple Rejection – dB 1.285 0 30 Figure 4. Load Transient Response 1.27 V OUT – V 40 Tim e – µs Figure 3. Load Transient Response 1.255 20 0 10 -10 -30 9 -20 60 -5 70 40 50 20 30 0 10 -10 -30 -20 9 9.2 CADJ = 10 µF CADJ = 0 µF -5 50 VOUT V OUT Deviation – V Load Current – A -2 -2.5 10.6 IOUT IOUT -1.5 VOUT Deviation ̶ V 11 60 0 IOUT – A Figure 5. Line Regulation Figure 6. Ripple Rejection vs Output Current Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 7 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com -75 -90 -70 -80 -65 -70 Ripple Rejection – dB Ripple Rejection – dB Typical Characteristics (continued) -60 -55 -50 V IN – V OUT = 15 V IOUT = 500 m A f = 120 Hz TA = 25°C -45 -40 10 15 20 25 30 35 V OUT – V -60 CADJ = 10 µF -50 -40 -30 -10 100 100 1k 1000 10k 10000 100k 100000 1M 1000000 Frequency – Hz Figure 7. Ripple Rejection vs Output Voltage 8 CADJ = 0 µF -20 -35 5 V IN = 15 V V OUT = 10 V IOUT = 500 m A TA = 25°C Figure 8. Ripple Rejection vs Frequency Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 8 Detailed Description 8.1 Overview The LM317 device is an adjustable three-terminal positive-voltage regulator capable of supplying up to 1.5 A over an output-voltage range of 1.25 V to 37 V. It requires only two external resistors to set the output voltage. The device features a typical line regulation of 0.01% and typical load regulation of 0.1%. It includes current limiting, thermal overload protection, and safe operating area protection. Overload protection remains functional even if the ADJUST terminal is disconnected. The LM317 device is versatile in its applications, including uses in programmable output regulation and local oncard regulation. Or, by connecting a fixed resistor between the ADJUST and OUTPUT terminals, the LM317 device can function as a precision current regulator. An optional output capacitor can be added to improve transient response. The ADJUST terminal can be bypassed to achieve very high ripple-rejection ratios, which are difficult to achieve with standard three-terminal regulators. 8.2 Functional Block Diagram Input Iadj + 1.25 V Adj. Over Temp & Over Current Protection Output 8.3 Feature Description 8.3.1 NPN Darlington Output Drive NPN Darlington output topology provides naturally low output impedance and an output capacitor is optional. 3-V headroom is recommended (VI – VO) to support maximum current and lowest temperature. 8.3.2 Overload Block Over-current and over-temperature shutdown protects the device against overload or damage from operating in excessive heat. 8.3.3 Programmable Feedback Op amp with 1.25-V offset input at the ADJUST terminal provides easy output voltage or current (not both) programming. For current regulation applications, a single resistor whose resistance value is 1.25 V/IO and power rating is greater than (1.25 V)2/R should be used. For voltage regulation applications, two resistors set the output voltage. Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 9 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com 8.4 Device Functional Modes 8.4.1 Normal Operation The device OUTPUT pin will source current necessary to make OUTPUT pin 1.25 V greater than ADJUST terminal to provide output regulation. 8.4.2 Operation With Low Input Voltage The device requires up to 3-V headroom (VI – VO) to operate in regulation. The device may drop out and OUTPUT voltage will be INPUT voltage minus drop out voltage with less headroom. 8.4.3 Operation at Light Loads The device passes its bias current to the OUTPUT pin. The load or feedback must consume this minimum current for regulation or the output may be too high. See the Electrical Characteristics table for the minimum load current needed to maintain regulation. 8.4.4 Operation In Self Protection When an overload occurs the device shuts down Darlington NPN output stage or reduces the output current to prevent device damage. The device will automatically reset from the overload. The output may be reduced or alternate between on and off until the overload is removed. 10 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 9.1 Application Information The flexibility of the LM317 allows it to be configured to take on many different functions in DC power applications. 9.2 Typical Application D1 1N4002 Input VI Output LM317 R1 240 W Adjust Ci 0.1 µF VO Vref = 1.25 V IAdj D2 1N4002 CO 1.0 µF CADJ R2 Figure 9. Adjustable Voltage Regulator 9.2.1 Design Requirements • R1 and R2 are required to set the output voltage. • CADJ is recommended to improve ripple rejection. It prevents amplification of the ripple as the output voltage is adjusted higher. • Ci is recommended, particularly if the regulator is not in close proximity to the power-supply filter capacitors. A 0.1-µF or 1-µF ceramic or tantalum capacitor provides sufficient bypassing for most applications, especially when adjustment and output capacitors are used. • CO improves transient response, but is not needed for stability. • Protection diode D2 is recommended if CADJ is used. The diode provides a low-impedance discharge path to prevent the capacitor from discharging into the output of the regulator. • Protection diode D1 is recommended if CO is used. The diode provides a low-impedance discharge path to prevent the capacitor from discharging into the output of the regulator. 9.2.2 Detailed Design Procedure VO is calculated as shown in Equation 1. IADJ is typically 50 µA and negligible in most applications. VO = VREF (1 + R2 / R1) + (IADJ × R2) (1) Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 11 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com Typical Application (continued) 9.2.3 Application Curves 20 10.10 20 10.12 CADJ = 0 µF 10.08 19 18 10.06 18 17 10.04 VOUT 10.10 V IN Change – V VIN 16 V OUT – V V IN Change – V VOUT 10.02 10.08 10.06 17 10.04 VIN V OUT – V 19 CADJ = 10 µF 16 10.02 10.00 Tim e – µs 65 55 45 35 25 15 5 -5 -15 9.98 -25 65 55 45 35 25 14 15 9.98 5 14 -5 15 -15 10.00 -25 15 Tim e – µs Figure 10. Line-Transient Response Figure 11. Line-Transient Response 9.3 System Examples 9.3.1 0-V to 30-V Regulator Circuit æ R + R3 ö VOUT = VREF ç 1 + 2 ÷ - 10 V R1 ø è Here, the voltage is determined by LM317 +35 V INPUT OUTPUT ADJUST VO R1 120 W −10 V C1 0.1 µF R3 680 W R2 3 kW Figure 12. 0-V to 30-V Regulator Circuit 12 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 System Examples (continued) 9.3.2 Adjustable Regulator Circuit With Improved Ripple Rejection C2 helps to stabilize the voltage at the adjustment pin, which helps reject noise. Diode D1 exists to discharge C2 in case the output is shorted to ground. LM317 VI INPUT VO OUTPUT ADJUST R1 240 W D1 1N4002 C1 0.1 µF C3 1 µF R2 5 kW C2 10 µF Figure 13. Adjustable Regulator Circuit with Improved Ripple Rejection 9.3.3 Precision Current-Limiter Circuit This application limits the output current to the ILIMIT in the diagram. LM317 VI INPUT 1.2 R1 Ilimit OUTPUT R1 ADJUST Figure 14. Precision Current-Limiter Circuit 9.3.4 Tracking Preregulator Circuit This application keeps a constant voltage across the second LM317 in the circuit. R2 720 Ω ADJUST VI INPUT R1 240 Ω OUTPUT LM317 LM317 INPUT OUTPUT VO R3 120 Ω ADJUST C1 0.1 µF C2 1 µF Output Adjust R4 1 kΩ Figure 15. Tracking Preregulator Circuit Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 13 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com System Examples (continued) 9.3.5 1.25-V to 20-V Regulator Circuit With Minimum Program Current Because the value of VREF is constant, the value of R1 determines the amount of current that flows through R1 and R2. The size of R2 determines the IR drop from ADJUSTMENT to GND. Higher values of R2 translate to higher VOUT. æ R + R3 ö VOUT = VREF ç 1 + 2 ÷ - 10 V R1 ø è (2) (R1 + R2 )min = VoIreg(min) (3) LM317 INPUT VI OUTPUT ADJUST VO R1 1.2 kΩ R2 20 kΩ Figure 16. 1.25-V to 20-V Regulator Circuit With Minimum Program Current 9.3.6 Battery-Charger Circuit The series resistor limits the current output of the LM317, minimizing damage to the battery cell. R2 · § V OUT 1.25 V u ¨ 1 R1 ¸¹ © IOUT(short) = 1.25V RS (4) (5) § Output Impedance RS u ¨1 © R2 · R1 ¸¹ (6) LM317 VI INPUT RS 0.2 W OUTPUT ADJUST R1 240 W R2 2.4 kW Figure 17. Battery-Charger Circuit 14 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 System Examples (continued) 9.3.7 50-mA Constant-Current Battery-Charger Circuit The current limit operation mode can be used to trickle charge a battery at a fixed current. ICHG = 1.25 V ÷ 24 Ω. VI should be greater than VBAT + 4.25 V. (1.25 V [VREF] + 3 V [headroom]) LM317 VI INPUT 24 Ω OUTPUT ADJUST Figure 18. 50-mA Constant-Current Battery-Charger Circuit 9.3.8 Slow Turn-On 15-V Regulator Circuit The capacitor C1, in combination with the PNP transistor, helps the circuit to slowly start supplying voltage. In the beginning, the capacitor is not charged. Therefore output voltage starts at VC1+ VBE + 1.25 V = 0 V + 0.65 V + 1.25 V = 1.9 V. As the capacitor voltage rises, VOUT rises at the same rate. When the output voltage reaches the value determined by R1 and R2, the PNP will be turned off. LM317 VI INPUT OUTPUT VO = 15 V R1 240 Ω ADJUST D1 1N4002 R3 50 kΩ R2 2.7 kΩ 2N2905 C1 25 µF Figure 19. Slow Turn-On 15-V Regulator Circuit 9.3.9 AC Voltage-Regulator Circuit These two LM317s can regulate both the positive and negative swings of a sinusoidal AC input. LM317 VI INPUT OUTPUT ADJUST 480 Ω 12 VI(PP) 120 Ω 480 Ω ADJUST VI INPUT 120 Ω 6 VO(PP) 2 W (TYP) OUTPUT LM317 Figure 20. AC Voltage-Regulator Circuit Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 15 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com System Examples (continued) 9.3.10 Current-Limited 6-V Charger Circuit As the charge current increases, the voltage at the bottom resistor increases until the NPN starts sinking current from the adjustment pin. The voltage at the adjustment pin drops, and consequently the output voltage decreases until the NPN stops conducting. LM317 INPUT VI+ OUTPUT ADJUST R1 240 W R2 1.1 kW R3 VI− Figure 21. Current-Limited 6-V Charger Circuit 9.3.11 Adjustable 4-A Regulator Circuit This application keeps the output current at 4 A while having the ability to adjust the output voltage using the adjustable (1.5 kΩ in schematic) resistor. LM317 VI INPUT 0.2 Ω OUTPUT ADJUST LM317 INPUT 0.2 Ω OUTPUT ADJUST 4.5 V to 25 LM317 INPUT V 0.2 Ω OUTPUT ADJUST 5 kΩ 100 Ω TL084 + 2N2905 5 kΩ _ 150 Ω 200 pF 1.5 k Ω Figure 22. Adjustable 4-A Regulator Circuit 16 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 System Examples (continued) 9.3.12 High-Current Adjustable Regulator Circuit The NPNs at the top of the schematic allow higher currents at VOUT than the LM317 can provide, while still keeping the output voltage at levels determined by the adjustment pin resistor divider of the LM317. TIP73 2N2905 VI 500 W 5 kW 22 W LM317 INPUT VO OUTPUT ADJUST 120 W 1N4002 10 µF 47 µF 10 µF Figure 23. High-Current Adjustable Regulator Circuit Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 17 LM317 SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 www.ti.com 10 Power Supply Recommendations The LM317 is designed to operate from an input voltage supply range between 1.25 V to 37 V greater than the output voltage. If the device is more than six inches from the input filter capacitors, an input bypass capacitor, 0.1 μF or greater, of any type is needed for stability. 11 Layout 11.1 Layout Guidelines • • • TI recommends that the input terminal be bypassed to ground with a bypass capacitor. The optimum placement is closest to the input terminal of the device and the system GND. Take care to minimize the loop area formed by the bypass-capacitor connection, the input terminal, and the system GND. For operation at full rated load, TI recommends to use wide trace lengths to eliminate I × R drop and heat dissipation. 11.2 Layout Example OUTPUT Ground COUT R2 Power INPUT OUTPUT R1 ADJ/GND Cadj High Frequency Bypass Capacitor 0.1μF 10μF High Input Bypass Capacitor Ground Figure 24. Layout Example 18 Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 LM317 www.ti.com SLVS044Y – SEPTEMBER 1997 – REVISED APRIL 2020 12 Device and Documentation Support 12.1 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 12.2 Support Resources TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight from the experts. Search existing answers or ask your own question to get the quick design help you need. Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. 12.3 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 12.4 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 12.5 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Submit Documentation Feedback Copyright © 1997–2020, Texas Instruments Incorporated Product Folder Links: LM317 19 PACKAGE OPTION ADDENDUM www.ti.com 13-Aug-2021 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LM317DCY ACTIVE SOT-223 DCY 4 80 RoHS & Green SN Level-2-260C-1 YEAR 0 to 125 L3 LM317DCYG3 ACTIVE SOT-223 DCY 4 80 RoHS & Green SN Level-2-260C-1 YEAR 0 to 125 L3 LM317DCYR ACTIVE SOT-223 DCY 4 2500 RoHS & Green SN Level-2-260C-1 YEAR 0 to 125 L3 LM317DCYRG3 ACTIVE SOT-223 DCY 4 2500 RoHS & Green SN Level-2-260C-1 YEAR 0 to 125 L3 LM317KCS ACTIVE TO-220 KCS 3 50 RoHS & Green SN N / A for Pkg Type 0 to 125 LM317 LM317KCSE3 ACTIVE TO-220 KCS 3 50 RoHS & Green SN N / A for Pkg Type 0 to 125 LM317 LM317KCT ACTIVE TO-220 KCT 3 50 RoHS & Non-Green SN N / A for Pkg Type 0 to 125 LM317 LM317KTTR ACTIVE DDPAK/ TO-263 KTT 3 500 RoHS & Green SN Level-3-245C-168 HR 0 to 125 LM317 LM317KTTRG3 ACTIVE DDPAK/ TO-263 KTT 3 500 RoHS & Green SN Level-3-245C-168 HR 0 to 125 LM317 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
LM317KCE3 价格&库存

很抱歉,暂时无法提供与“LM317KCE3”相匹配的价格&库存,您可以联系我们找货

免费人工找货