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LP2982IM5X-3.8

LP2982IM5X-3.8

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    SOT23-5

  • 描述:

    IC REG LDO 3.8V 50MA SOT23-5

  • 数据手册
  • 价格&库存
LP2982IM5X-3.8 数据手册
Sample & Buy Product Folder Support & Community Tools & Software Technical Documents LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 LP2982 50-mA Micropower Ultra-Low-Dropout LDO in SOT-23 Package 1 Features 3 Description • • • • • • • • • • • • • The LP2982 is a 50-mA, fixed-output voltage LDO designed to provide ultra-low dropout and lower noise in battery-powered applications. 1 2.1-V to 16-V Input Voltage Ultra-Low-Dropout Voltage Ensured 50-mA Output Current Typical Dropout Voltage 180 mV at 80 mA Requires Minimum External Components < 1 μA Quiescent Current When Shut Down Low Ground Pin Current at All Loads Output Voltage Accuracy 1% (A Grade) High Peak Current Capability (150 mA Typical) Wide Supply Voltage Range (16 V Maximum) Low ZOUT 0.3 Ω Typical (10 Hz to 1 MHz) Overtemperature and Overcurrent Protection −40°C to +125°C Junction Temperature Range Using an optimized vertically integrated PNP (VIP) process, the LP2982 delivers unequaled performance in all specifications critical to battery-powered designs: Dropout Voltage: Typically 120 mV at 50 mA load, and 7 mV at 1 mA load. Ground Pin Current: Typically 375 μA at 50 mA load, and 80 μA at 1 mA load. Sleep Mode: Less than 1-μA quiescent current when ON/OFF pin is pulled low. Precision Output: 1% tolerance output voltages available (A grade). 2 Applications • • • • Low Noise: By adding an external bypass capacitor, output noise can be reduced to 30 μV (typical). Cellular Phones Palmtop and Laptop Computers Personal Digital Assistants (PDA) Camcorders, Personal Stereos, Cameras Device Information(1) PART NUMBER LP2982 PACKAGE BODY SIZE (NOM) SOT-23 (5) 2.90 mm × 1.60 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Simplified Schematic IN VIN OUT CIN ON/OFF ON VOUT COUT ON/OFF BYPASS OFF GND CBYPASS 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. LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 6.6 4 4 4 5 5 7 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Typical Characteristics .............................................. Detailed Description ............................................ 13 7.1 Overview ................................................................. 13 7.2 Functional Block Diagram ....................................... 13 7.3 Feature Description................................................. 13 7.4 Device Functional Modes........................................ 14 8 Application and Implementation ........................ 15 8.1 Application Information............................................ 15 8.2 Typical Application ................................................. 15 9 Power Supply Recommendations...................... 20 10 Layout................................................................... 20 10.1 Layout Guidelines ................................................. 20 10.2 Layout Example .................................................... 20 11 Device and Documentation Support ................. 21 11.1 11.2 11.3 11.4 11.5 11.6 Third-Party Products Disclaimer ........................... Documentation Support ........................................ Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 21 21 21 21 21 21 12 Mechanical, Packaging, and Orderable Information ........................................................... 21 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision J (April 2013) to Revision K Page • Deleted TM symbol from VIP - no longer trademarked; changed word in title from "Regulator" to "LDO" ........................... 1 • Added Pin Configuration and Functions section, ESD Ratings 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 • Changed update typical application drawing and change pin names from Vin, Vout to IN and OUT; remove last paragraph of Description beginning "Four output voltage versions..." ................................................................................... 1 • Deleted Lead temperature row from Abs Max; this information is in the POA; remove "(survival)" and "(operating)" from rows in Abs Max table ................................................................................................................................................... 4 • Added "ON/OFF input voltage" to ROC table ........................................................................................................................ 4 • Changed VIN – VO to "VDO" .................................................................................................................................................... 5 Changes from Revision I (April 2013) to Revision J • 2 Page Changed layout of National Semiconductor Data Sheet to TI format .................................................................................. 18 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 5 Pin Configuration and Functions DBV Package 5-Pin SOT-23 Top View Pin Descriptions PIN NUMBER NAME TYPE 1 IN Input 2 GND — 3 ON/OFF Input 4 BYPASS Input/Output 5 OUT Output DESCRIPTION Input voltage Common ground (device substrate) Logic high enable input Bypass capacitor for low noise operation Regulated output voltage Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 3 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) (2) Operating junction temperature Power dissipation (3) MIN MAX UNIT −40 125 °C Internally limited Input supply voltage −0.3 16 V Shutdown input voltage −0.3 16 V −0.3 9 V Output voltage (4) IOUT Short-circuit protected Input-output voltage (5) −0.3 16 V Storage temperature –65 150 °C (1) (2) (3) (4) (5) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. If Military/Aerospace-specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and specifications. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, RθJA, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using P(MAX) = (TJ(MAX) – TA) / RθJA. The value of RθJA for the SOT-23 package is 169°C/W. Exceeding the maximum allowable power dissipation causes excessive die temperature, and the regulator will go into thermal shutdown. If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2982 output must be diode-clamped to ground. The output PNP structure contains a diode between the IN and OUT pins that is normally reverse-biased. Reversing the polarity from VIN to VOUT turns on this diode (see Reverse Current Path). 6.2 ESD Ratings VALUE V(ESD) (1) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) Pins 1, 2 and 5 ±2000 Pins 3 and 4 ±1000 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) Operating junction temperature Input supply voltage ON/OFF input voltage 4 Submit Documentation Feedback MIN MAX UNIT −40 125 °C 2.1 16 V 0 16 V Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 6.4 Thermal Information LP2982 THERMAL METRIC (1) DBV (SOT-23) UNIT 5 PINS RθJA Junction-to-ambient thermal resistance, High-K (2) 175.7 °C/W RθJC(top) Junction-to-case (top) thermal resistance 121.8 °C/W RθJB Junction-to-board thermal resistance 29.5 °C/W ψJT Junction-to-top characterization parameter 16.1 °C/W ψJB Junction-to-board characterization parameter 29.0 °C/W (1) (2) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. Thermal resistance value RθJA is based on the EIA/JEDEC High-K printed circuit board defined by: JESD51-7 - High Effective Thermal Conductivity Test Board for Leaded Surface Mount Packages. 6.5 Electrical Characteristics Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 1 mA, COUT = 1 μF, VON/OFF = 2 V. PARAMETER TEST CONDITIONS IL = 1 mA ΔVO ΔVO/ΔVIN Output voltage tolerance Output voltage line regulation 1 mA < IL < 50 mA 1 mA < IL < 50 mA –40°C ≤ TJ ≤ 125°C VO(NOM) + 1 V ≤ VIN ≤ 16 V LP2982AI-XX (1) MIN TYP −1.5 1.5 −2 2 −2 2 −3.5 3.5 0.007 VO(NOM) + 1 V ≤ VIN ≤ 16 V –40°C ≤ TJ ≤ 125°C IL = 10 mA, –40°C ≤ TJ ≤ 125°C 120 IL = 80 mA, –40°C ≤ TJ ≤ 125°C IL = 0 mA, –40°C ≤ TJ ≤ 125°C IL = 1 mA, –40°C ≤ TJ ≤ 125°C IL = 10 mA, –40°C ≤ TJ ≤ 125°C IL = 50 mA, –40°C ≤ TJ ≤ 125°C IL = 80 mA, –40°C ≤ TJ ≤ 125°C (1) (2) 120 225 95 110 220 600 750 mV 150 225 180 225 325 65 95 125 80 110 170 140 220 460 375 1200 525 VON/OFF < 0.15 V –40°C ≤ TJ ≤ 125°C 150 60 90 460 375 VON/OFF < 0.3 V 15 40 170 140 IL = 80 mA 60 %/V 5 125 80 IL = 50 mA 10 325 65 IL = 10 mA 7 225 180 IL = 1 mA 3 90 IL = 50 mA, –40°C ≤ TJ ≤ 125°C IL = 0 mA 10 0.014 1 15 40 IL = 80 mA 3 %VNOM 0.032 5 7 IL = 50 mA 0.007 0.032 1 IL = 10 mA 0.014 UNIT MAX 1 IL = 1 mA, –40°C ≤ TJ ≤ 125°C Ground pin current TYP 1.5 IL = 1 mA IGND MIN −1 IL = 0 mA, –40°C ≤ TJ ≤ 125°C Dropout voltage (2) MAX −1.5 IL = 0 mA VDO LP2982I-XX (1) 600 μA 1200 525 1400 750 1400 0.01 0.8 0.01 0.8 0.1 2 0.1 2 Temperature range are ensured through correlation using statistical quality control (SQC) methods. The limits are used to calculate average outgoing quality level (AOQL). Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1-V differential. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 5 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Electrical Characteristics (continued) Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 1 mA, COUT = 1 μF, VON/OFF = 2 V. PARAMETER TEST CONDITIONS LP2982AI-XX (1) MIN High = O/P ON VON/OFF ON/OFF input voltage (3) TYP MIN Low = O/P OFF 1.6 0.55 0.55 0.01 0.01 5 VON/OFF = 5 V –40°C ≤ TJ ≤ 125°C Peak output current VOUT ≥ VO(NOM) − 5% en Output noise voltage (RMS) BW = 300 Hz to 50 kHz COUT = 10 μF –2 μA 5 15 150 UNIT 0.15 –2 VON/OFF = 5 V MAX V 0.15 VON/OFF = 0 V –40°C ≤ TJ ≤ 125°C IO(PK) TYP 1.4 1.6 VON/OFF = 0 V ON/OFF input current MAX 1.4 High = O/P ON –40°C ≤ TJ ≤ 125°C Low = O/P OFF –40°C ≤ TJ ≤ 125°C ION/OFF LP2982I-XX (1) 15 100 100 mA 30 30 μV ΔVO/ΔVIN Ripple rejection ƒ = 1 kHz, COUT = 10 μF 45 45 dB IO(MAX) RL = 0 Ω (steady state) (4) 150 150 mA (3) (4) 6 Short-circuit current The ON/OFF inputs must be properly driven to prevent misoperation. For details, see Operation With ON/OFF Control. See related curve(s) in Typical Characteristics section. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 6.6 Typical Characteristics Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 1. Output Voltage vs Temperature Figure 2. Output Voltage vs Temperature Figure 3. Output Voltage vs Temparature Figure 4. Dropout Characteristics Figure 5. Dropout Characteristics Figure 6. Dropout Characteristics Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 7 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Typical Characteristics (continued) Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 7. Dropout Voltage vs Temperature Figure 8. Dropout Voltage vs Load Current Figure 9. GND Pin Current vs Temperature Figure 10. GND Pin Current vs Load Current Figure 12. Input Current vs VIN Figure 11. Input Current vs VIN 8 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 Typical Characteristics (continued) Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 13. Line Transient Response Figure 14. Line Transient Response Figure 15. Load Transient Response Figure 16. Load Transient Response Figure 17. Load Transient Response Figure 18. Load Transient Response Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 9 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Typical Characteristics (continued) Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 19. Short-Circuit Current Figure 20. Instantaneous Short-Circuit Current vs Temperature Figure 21. Short-Circuit Current Figure 22. Instantaneous Short Circuit Current vs Output Voltage Figure 23. Output Impedance vs Frequency 10 Submit Documentation Feedback Figure 24. Output Impedance vs Frequency Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 Typical Characteristics (continued) Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 25. ON/OFF Pin Current VsvON/OFF Figure 26. ON/OFF Threshold vs Temperature Figure 27. Input-to-Output Leakage vs Temperature Figure 28. Output Reverse Leakage vs Temperature Figure 30. Output Noise Density Figure 29. Output Noise Density Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 11 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Typical Characteristics (continued) Unless otherwise specified: TA = 25°C, VIN = VO(NOM) + 1 V, COUT = 4.7 μF, CIN = 1 μF, all voltage options, ON/OFF pin tied to VIN. Figure 31. Output Noise Density Figure 32. Ripple Rejection Figure 34. Turnon Waveform Figure 33. Turnon Waveform Figure 35. Turnon Waveform 12 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 7 Detailed Description 7.1 Overview The LP2982 is a 50-mA, fixed-output voltage regulator designed specifically to meet the requirements of batterypowered applications. Available in assorted output voltages (refer to the package option addendum (POA) at the back of this datasheet for the available voltage and package options), the device has an output tolerance of 1% for the A grade (1.5% for the non-A version). Using a VIP process, the LP2982 contains these features to facilitate battery-powered designs: • Fixed 5-V, 3.3-V, and 3-V output versions • Very high-accuracy 1.23-V reference • Low-dropout voltage, typical dropout of 120 mV at a 50-mA load current and 7 mV at 1-mA load • Low ground current, typically 375 μA at 50-mA load and 80 μA at 1-mA load • A sleep-mode feature is available, allowing the regulator to consume only 1 µA (typical) when the ON/OFF pin is pulled low. • Overtemperature protection and overcurrent protection circuitry is designed to safeguard the device during unexpected conditions. 7.2 Functional Block Diagram 7.3 Feature Description 7.3.1 Multiple Voltage Options To meet the different application requirements, the LP2982 provides multiple fixed output options (see POA). 7.3.2 High-Accuracy Output Voltage With special careful design to minimize all contributions to the output voltage error, the LP2982 distinguishes itself as a very high-accuracy output voltage micropower LDO. This includes a tight initial tolerance (1% typical), extremely good line regulation (0.007%/V typical), and a very low output voltage temperature coefficient, making the device an ideal low-power voltage reference. 7.3.3 Ultra-Low-Dropout Voltage Generally speaking, the dropout voltage often refers to the voltage difference between the input and output voltage (VDO = VIN – VOUT), where the main current pass element (PNP) is fully on and is characterized by the classic VCE(SAT) of the transistor. VDO indirectly specifies a minimum input voltage above the nominal programmed output voltage at which the output voltage is expected to remain within its accuracy boundary. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 13 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com Feature Description (continued) 7.3.4 Low Ground Current The LP2982 uses a vertical PNP process which allows for quiescent currents that are considerably lower than those associated with traditional lateral PNP regulators, typically 375 μA at 50-mA load and 80 μA at 1-mA load. 7.3.5 Sleep Mode When pulling the ON/OFF pin to a low level (VON/OFF < 0.15 V), LP2982 enters sleep mode, and less than 1-μA quiescent current is consumed. This function is designed for the application which needs a sleep mode to effectively enhance battery life cycle. 7.3.6 Short-Circuit Protection (Current Limit) The internal current-limit circuit is used to protect the LDO against high-load current faults or shorting events. The LDO is not designed to operate in a steady-state current limit. During a current-limit event, the LDO sources constant current. Therefore, the output voltage falls when load impedance decreases. If a current limit occurs and the resulting output voltage is low, excessive power may be dissipated across the LDO resulting in a thermal shutdown of the output. A foldback feature limits the short-circuit current to protect the regulator from damage under all load conditions. If OUT is forced below 0 V before EN goes high, and the load current required exceeds the foldback current limit, the device may not start up correctly. 7.3.7 Thermal Protection The LP2982 contains a thermal shutdown protection circuit to turn off the output current when excessive heat is dissipated in the LDO. The thermal time-constant of the semiconductor die is fairly short, and thus the output cycles on and off at a high rate when thermal shutdown is reached until the power dissipation is reduced. The internal protection circuitry of the LM2982 is designed to protect against thermal overload conditions. The circuitry is not intended to replace proper heat sinking. Continuously running the device into thermal shutdown degrades its reliability. 7.4 Device Functional Modes 7.4.1 Operation with VOUT(TARGET) + 1 V ≤ VIN < 16 V The device operates if the input voltage is equal to, or exceeds, VOUT(TARGET) + 0.6 V. At input voltages below the minimum VIN requirement, the device does not operate correctly, and output voltage may not reach target value. 7.4.2 Operation With ON/OFF Control If the voltage on the ON/OFF pin is less than 0.15 V, the device is disabled, and the shutdown current does not exceed 1 μA. Raising ON/OFF above 1.4 V initiates the start-up sequence of the device. 14 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 8 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. 8.1 Application Information The LP2982 is a linear voltage regulator operating from 2.1 V to 16 V on the input and regulates voltages between 3 V to 5 V with 1% accuracy and 50-mA maximum output current. Efficiency is defined by the ratio of output voltage to input voltage because the LP2982 is a linear voltage regulator. To achieve high efficiency, the dropout voltage (VIN – VOUT) must be as small as possible, thus requiring a very-low-dropout LDO. Successfully implementing an LDO in an application depends on the application requirements. If the requirements are simply input voltage and output voltage, compliance specifications (such as internal power dissipation or stability) must be verified to ensure a solid design. If timing, start-up, noise, power supply rejection ratio (PSRR), or any other transient specification is required, then the design becomes more challenging. 8.2 Typical Application IN VIN VOUT OUT CIN COUT (Tantalum) 1 µF ON/OFF 2.2 µF (5-V device) 4.7 µF (3-V and 3.3-V devices) ON/OFF BYPASS ON CBYPASS OFF GND 0.01 µF ON/OFF input must be actively terminated. Tie to VIN if this function is not to be used. Minimum output capacitance is shown to insure stability over full load current range. More capacitance provides superior dynamic performance and additional stability margin (see Capacitor Characteristics). Figure 36. LP2982 Typical Application 8.2.1 Design Requirements PARAMETER DESIGN REQUIREMENT Input voltage 5 V ±10% Output voltage 3.3 V ±3.5% Output current 50 mA Ambient temperature 85°C 8.2.2 Detailed Design Procedure 8.2.2.1 External Capacitors Like any low-dropout regulator, the external capacitors used with the LP2982 must be carefully selected to assure regulator loop stability. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 15 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com 8.2.2.1.1 Input Capacitor An input capacitor with a value ≥ 1 μF is required with the LP2982 (amount of capacitance can be increased without limit). This capacitor must be located a distance of not more than 0.5 inches from the input pin of the LP2982 and returned to a clean analog ground. Any good quality ceramic or tantalum can be used for this capacitor. 8.2.2.1.2 Output Capacitor The output capacitor must meet both the requirement for minimum amount of capacitance and equivalent series resistance (ESR) value. Curves are provided which show the allowable ESR range as a function of load current for various output voltages and capacitor values (refer to Figure 40 and Figure 41). NOTE Important: The output capacitor must maintain its ESR in the stable region over the full operating temperature range to ensure stability. Also, capacitor tolerance and variation with temperature must be considered to ensure the minimum amount of capacitance is provided at all times. This capacitor must be located not more than 0.5 inches from the OUT pin of the LP2982 and returned to a clean analog ground. IN VIN VOUT OUT COUT (MLCC) CIN 1 µF ON/OFF ON 2.2 µF (5-V device) 4.7 µF (3-V and 3.3-V devices) RESR ON/OFF BYPASS CBYPASS 1Ÿ OFF GND 0.01 µF Figure 37. Typical Application With Ceramic COUT Series R 8.2.2.1.3 Bypass Capacitor The 0.01-μF capacitor connected to the bypass pin to reduce noise must have very low leakage. The current flowing out of the bypass pin comes from the bandgap reference, which is used to set the output voltage. This capacitor leakage current causes the output voltage to decline by an amount proportional to the current. Typical values are −0.015%/nA at −40°C, −0.021%/nA at 25°C, and −0.035%/nA at 125°C. This data is valid up to a maximum leakage current of about 500 nA, beyond which the bandgap is so severely loaded that it can not function. Care must be taken to ensure that the capacitor selected does not have excessive leakage current over the operating temperature range of the application. A high-quality ceramic capacitor which uses either NPO or COG type dielectric material typically has very low leakage. Small surface mount polypropylene or polycarbonate film capacitors also have extremely low leakage, but are slightly larger than ceramics. 16 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 8.2.2.2 Capacitor Characteristics 8.2.2.2.1 Tantalum Tantalum capacitors are the best choice for use with the LP2982. Most good quality tantalums can be used with the LP2982, but check the manufacturer's data sheet to be sure the ESR is in range. It is important to remember that ESR increases at lower temperatures and a capacitor that is near the upper limit for stability at room temperature can cause instability when it gets cold. In applications which must operate at very low temperatures, it may be necessary to parallel the output tantalum capacitor with a ceramic capacitor to prevent the ESR from going up too high (see Ceramic for important information on ceramic capacitors). 8.2.2.2.2 Ceramic TI does not recommend use of ceramic capacitors at the output of the LP2982. This is because the ESR of a ceramic can be low enough to go below the minimum stable value for the LP2982. A 2.2-μF ceramic was measured and found to have an ESR of about 15 mΩ, which is low enough to cause oscillations. If a ceramic capacitor is used on the output, a 1-Ω resistor must be placed in series with the capacitor. 8.2.2.2.3 Aluminum Because of large physical size, aluminum electrolytics are not typically used with the LP2982. They must meet the same ESR requirements over the operating temperature range, more difficult because of their steep increase at cold temperature. An aluminum electrolytic can exhibit an ESR increase of as much as 50× when going from 20°C to −40°C. Also, some aluminum electrolytics are not operational below −25°C because the electrolyte can freeze. 8.2.2.3 Reverse Current Path The internal PNP power transistor used as the pass element in the LP2982 has an inherent diode connected between the regulator output and input. During normal operation (where the input voltage is higher than the output) this diode is reverse biased (see Figure 38). VIN VOUT PNP GND Figure 38. LP2982 Reverse Current Path However, if the input voltage is more than a VBE below the output voltage, this diode will turn ON and current will flow into the regulator output. In such cases, a parasitic SCR can latch which will allow a high current to flow into the VIN pin and out the ground pin, which can damage the part. The internal diode can also be turned on if the input voltage is abruptly stepped down to a voltage which is a VBE below the output voltage. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 17 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com In any application where the output voltage may be higher than the input voltage, an external Schottky diode must be connected from VIN to VOUT (cathode on VIN, anode on VOUT; see Figure 39), to limit the reverse voltage across the LP2982 to 0.3 V (see Absolute Maximum Ratings). SCHOTTKY DIODE VIN VOUT PNP GND Figure 39. Adding External Schottky Diode Protection 8.2.2.4 ON/OFF Input Operation The LP2982 is shut off by pulling the ON/OFF input low, and turned on by driving the input high. If this feature is not to be used, the ON/OFF input should be tied to VIN to keep the regulator on at all times (the ON/OFF input must not be left floating). To ensure proper operation, the signal source used to drive the ON/OFF input must be able to swing above and below the specified turnon/turnoff voltage thresholds which specify an ON or OFF state (see Electrical Characteristics). The ON/OFF signal may come from either a totem-pole output, or an open-collector output with pullup resistor to the LP2982 input voltage or another logic supply. The high-level voltage may exceed the LP2982 input voltage, but must remain within the Absolute Maximum Ratings for the ON/OFF pin. It is also important that the turnon/turnoff voltage signals applied to the ON/OFF input have a slew rate which is greater than 40 mV/μs. NOTE IMPORTANT: The regulator shutdown function does not operate correctly if a slow-moving signal is applied to the ON/OFF input. 8.2.2.5 Power Dissipation Knowing the device power dissipation and proper sizing of the thermal plane connected to the tab or pad is critical to ensuring reliable operation. Device power dissipation depends on input voltage, output voltage, and load conditions and can be calculated with Equation 1. PD(MAX) = (VIN(MAX) – VOUT) × IOUT (1) Power dissipation can be minimized, and greater efficiency can be achieved, by using the lowest available voltage drop option that is greater than the dropout voltage (VDO). However, keep in mind that higher voltage drops result in better dynamic (that is, PSRR and transient) performance. On the LP2982 SOT-23 (DBV) package, the primary conduction path for heat is through the five leads to the PCB. The ground pin (pin 2) is attached directly to the back side of the die and should be accorded extra copper area on the PCB. The maximum allowable junction temperature (TJ(MAX)) determines maximum power dissipation allowed (PD(MAX)) for the device package. Power dissipation and junction temperature are most often related by the junction-to-ambient thermal resistance (RθJA) of the combined PCB and device package and the temperature of the ambient air (TA), according to Equation 2 or Equation 3: 18 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 TJ(MAX) = TA(MAX) + (RθJA × PD(MAX)) PD = (TJ(MAX) – TA(MAX)) / RθJA (2) (3) Unfortunately, this RθJA is highly dependent on the heat-spreading capability of the particular PCB design, and therefore varies according to the total copper area, copper weight, and location of the planes. The RθJA recorded in Thermal Information is determined by the specific EIA/JEDEC JESD51-7 standard for PCB and copperspreading area and is to be used only as a relative measure of package thermal performance. For a welldesigned thermal layout, RθJA is actually the sum of the package junction-to-board thermal resistance (RθJB) plus the thermal resistance contribution by the PCB copper area acting as a heat sink. 8.2.2.6 Estimating Junction Temperature The EIA/JEDEC standard recommends the use of psi (Ψ) thermal characteristics to estimate the junction temperatures of surface mount devices on a typical PCB board application. These characteristics are not true thermal resistance values, but rather package specific thermal characteristics that offer practical and relative means of estimating junction temperatures. These psi metrics are determined to be significantly independent of copper-spreading area. The key thermal characteristics (ΨJT and ΨJB) are given in Thermal Information and are used in accordance with Equation 4 or Equation 5. TJ(MAX) = TTOP + (ΨJT × PD(MAX)) where • • PD(MAX) is explained in Equation 3 TTOP is the temperature measured at the center-top of the device package. TJ(MAX) = TBOARD + (ΨJB × PD(MAX)) (4) where • • PD(MAX) is explained in Equation 3. TBOARD is the PCB surface temperature measured 1 mm from the device package and centered on the package edge. (5) For more information about the thermal characteristics ΨJT and ΨJB, see Semiconductor and IC Package Thermal Metrics (SPRA953); for more information about measuring TTOP and TBOARD, see Using New Thermal Metrics (SBVA025); and for more information about the EIA/JEDEC JESD51 PCB used for validating RθJA, see the TI Application Report Thermal Characteristics of Linear and Logic Packages Using JEDEC PCB Designs (SZZA017). These application notes are available at www.ti.com. 8.2.3 Application Curves Figure 40. 5-V, 2.2-μF ESR Curves Figure 41. 3-V, 4.7-μF ESR Curves Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 19 LP2982 SNVS128K – MARCH 2000 – REVISED JUNE 2016 www.ti.com 9 Power Supply Recommendations The LP2982 is designed to operate from an input voltage supply range between between VOUT(NOM) + 1 V and 16 V. The input voltage range provides adequate headroom for the device to have a regulated output. This input supply must be well regulated. If the input supply is noisy, additional input capacitors with low ESR can help improve the output noise performance. 10 Layout 10.1 Layout Guidelines For best overall performance, place all circuit components on the same side of the circuit board and as near as practical to the respective LDO pin connections. Place ground return connections to the input and output capacitors, and to the LDO ground pin as close to each other as possible, connected by a wide, component-side, copper surface. The use of vias and long traces to create LDO circuit connections is strongly discouraged and negatively affects system performance. This grounding and layout scheme minimizes inductive parasitics, and thereby reduces load-current transients, minimizes noise, and increases circuit stability. A ground reference plane is also recommended and is either embedded in the PCB itself or located on the bottom side of the PCB opposite the components. This reference plane serves to assure accuracy of the output voltage, shield noise, and behaves similar to a thermal plane to spread (or sink) heat from the LDO device. In most applications, this ground plane is necessary to meet thermal requirements. 10.2 Layout Example VIN Ground CIN IN OUT GND ON/ OFF COUT CBYPASS VOUT Ground BYPASS Figure 42. LP2982 Layout Example 20 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 LP2982 www.ti.com SNVS128K – MARCH 2000 – REVISED JUNE 2016 11 Device and Documentation Support 11.1 Third-Party Products Disclaimer TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE. 11.2 Documentation Support 11.2.1 Related Documentation For additional information, see the following: • TI Application Report Semiconductor and IC Package Thermal Metrics (SPRA953) • TI Application Report Using New Thermal Metrics (SBVA025) • TI Application Report Thermal Characteristics of Linear and Logic Packages Using JEDEC PCB Designs (SZZA017) 11.3 Community Resources The following links connect to TI community resources. Linked contents are 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. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.4 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 11.5 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 11.6 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 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 © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2982 21 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2022 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) Samples (4/5) (6) LP2982AIM5-3.0/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L20A LP2982AIM5-3.3/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L19A Samples LP2982AIM5-5.0/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L18A Samples LP2982AIM5X-3.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L20A Samples LP2982AIM5X-3.3/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L19A Samples LP2982AIM5X-5.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L18A Samples LP2982IM5-3.0/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L20B LP2982IM5-3.3/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L19B Samples LP2982IM5-5.0/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L18B Samples LP2982IM5X-3.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L20B Samples LP2982IM5X-3.3/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L19B Samples LP2982IM5X-5.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L18B Samples (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
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