LP2981AIM5-3.8/NOPB

Sample & Buy Product Folder Support & Community Tools & Software Technical Documents LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 LP2981-N Micropower 100-mA Ultralow Dropout Regulator in SOT-23 Package 1 Features 3 Description • • • • • • • • • • • • The LP2981-N is a 100-mA, fixed-output voltage regulator designed specifically to meet the requirements of battery-powered applications. 1 Operating Input Voltage Range: 2.1 V to 16 V Ultralow-Dropout Voltage Output Voltage Accuracy 0.75% (A Grade) Specified 100-mA Output Current < 1-μA Quiescent Current when Shutdown Low Ground Pin Current at All Load Currents High Peak Current Capability (300 mA Typical) Wide Supply Voltage Range (16 V Maximum) Fast Dynamic Response to Line and Load Low ZOUT Over Wide Frequency Range Overtemperature and Overcurrent Protection −40°C to 125°C Junction Temperature Range Dropout Voltage: Typically 200 mV at 100-mA load, and 7 mV at 1-mA load. Ground Pin Current: Typically 600 μA at 100-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: 0.75% tolerance output voltages available (A grade). 2 Applications • • • • Using an optimized Vertically Integrated PNP (VIP) process, the LP2981-N delivers unequaled performance in all specifications critical to batterypowered designs: Cellular Phones Palmtop and Laptop Computers Personal Digital Assistants (PDA) Camcorders, Personal Stereos, Cameras Assorted voltage options, from 2.5 V to 5 V, are available as standard products. Device Information(1) PART NUMBER LP2981-N 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. Typical Application VIN IN VOUT OUT COUT CIN GND ON/OFF ON/OFF NC Copyright © 2016, Texas Instruments Incorporated 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. LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 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 8 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics........................................... Typical Characteristics .............................................. Detailed Description ............................................ 14 7.1 Overview ................................................................. 14 7.2 Functional Block Diagram ....................................... 14 7.3 Feature Description................................................. 14 7.4 Device Functional Modes........................................ 15 8 Application and Implementation ........................ 16 8.1 Application Information............................................ 16 8.2 Typical Application ................................................. 16 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 Third-Party Products Disclaimer ........................... Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 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 M (September 2015) to Revision N • Page Changed update typical application drawing and change pin names from Vin, Vout to IN and OUT ................................... 1 Changes from Revision L (June 2015) to Revision M Page • Changed split out ESD values by specific pins ..................................................................................................................... 4 • Changed correct junction-to-case and junction-to-board values (typo from last format update) .......................................... 5 Changes from Revision K (April 2013) to Revision L Page • Changed "Nine" to "Assorted" ................................................................................................................................................ 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 text of NC pin description ....................................................................................................................................... 3 • Changed thermal value in footnote 3 .................................................................................................................................... 4 • Changed thermal values to TI measure ................................................................................................................................ 5 Changes from Revision J (January 2009) to Revision K • 2 Page Changed layout of National Data Sheet to TI format ........................................................................................................... 19 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 5 Pin Configuration and Functions DBV Package 5-Pin SOT-23 Top View Pin Functions PIN NO. 1 NAME TYPE IN I 2 GND — 3 ON/OFF I DESCRIPTION Input voltage pin Common ground (device substrate) Logic high enable input 4 NC — DO NOT CONNECT. Device pin 4 is reserved for post packaging test and calibration of the LP2989 VOUT accuracy. Device pin 2 must be left floating. Do not connect to any potential. Do not connect to ground. Any attempt to do pin continuity testing on device pin 2 is discouraged. Continuity test results will be variable depending on the actions of the factory calibration. Aggressive pin continuity testing (high voltage, or high current) on device pin 2 may activate the trim circuitry forcing VOUT to move out of tolerance. 5 OUT O Regulated output voltage Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 3 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 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 (survival) −0.3 16 V Input supply voltage (operating) 2.1 16 V Shutdown input voltage (survival) −0.3 16 V Output voltage (survival) (4) −0.3 9 V IOUT (survival) Short-circuit protected Input-output voltage (survival) (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, please 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 175.7°C/W. Exceeding the maximum allowable power dissipation will cause 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 LP2980-N 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 will turn 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) MIN MAX UNIT Operating junction temperature −40 125 °C Input supply voltage (operating) 2.1 16 V 4 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 6.4 Thermal Information LP2981-N THERMAL METRIC (1) DBV (SOT-23) UNIT 5 PINS RθJA Junction-to-ambient thermal resistance, High-K 175.7 °C/W RθJC(top) Junction-to-case (top) thermal resistance 78.0 °C/W RθJB Junction-to-board thermal resistance 30.8 °C/W ψJT Junction-to-top characterization parameter 2.8 °C/W ψJB Junction-to-board characterization parameter 30.3 °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance N/A °C/W (1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. 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. (1) PARAMETER TEST CONDITIONS ΔVO ΔVO/ΔVIN Output voltage line regulation MIN TYP −1.25 1.25 −2 2 1 mA < IL < 100 mA –40°C ≤ TJ ≤ 125°C −2.5 2.5 −3.5 3.5 VO(NOM) + 1 V ≤ VIN ≤ 16 V 0.007 VO(NOM) + 1 V ≤ VIN ≤ 16 V –40°C ≤ TJ ≤ 125°C 1 7 10 70 100 IL = 1 mA, –40°C ≤ TJ ≤ 125°C 3 7 10 70 100 250 15 IL = 0 mA, –40°C ≤ TJ ≤ 125°C 95 80 IL = 1 mA, –40°C ≤ TJ ≤ 125°C 110 200 IL = 25 mA, –40°C ≤ TJ ≤ 125°C 300 80 600 IL = 100 mA, –40°C ≤ TJ ≤ 125°C 800 110 170 200 550 IL = 100 mA 95 125 170 IL = 25 mA 250 375 65 125 IL = 1 mA mV 150 200 375 65 %/V 5 150 200 0.014 1 15 IL = 25 mA IL = 0 mA (3) 3 %VNOM 0.032 5 IL = 100 mA, –40°C ≤ TJ ≤ 125°C (2) 0.007 0.032 IL = 100 mA (1) 0.014 UNIT MAX 1 IL = 25 mA, –40°C ≤ TJ ≤ 125°C Ground pin current TYP 0.75 IL = 1 mA IGND MIN −1 IL = 0 mA, –40°C ≤ TJ ≤ 125°C Dropout voltage (3) MAX −0.75 IL = 0 mA VIN – VO LP2981I-XX (2) 1 mA < IL < 100 mA IL = 1 mA Output voltage tolerance LP2981AI-XX (2) 300 550 600 1500 μA 800 1500 VON/OFF < 0.3 V 0.01 0.8 0.01 0.8 VON/OFF < 0.15 V –40°C ≤ TJ ≤ 125°C 0.05 2 0.05 2 Minimum and maximum limits are ensured through test, design, or statistical correlation over the junction temperature (TJ) range of –40°C to 125°C, unless otherwise stated. Typical values represent the most likely parametric norm at TA = 25°C, and are provided for reference purposes only. Limits are 100% production tested at 25°C. Limits over the operating 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: LP2981-N 5 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 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.(1) PARAMETER TEST CONDITIONS LP2981AI-XX (2) MIN TYP High = O/P ON VON/OFF ON/OFF input voltage (4) (4) 6 Peak output current 1.6 Low = O/P OFF 0.5 0.5 0.01 0.01 5 –1 400 μA 5 15 150 UNIT 0.15 –1 VON/OFF = 5 V MAX V 0.15 VON/OFF = 0 V –40°C ≤ TJ ≤ 125°C VOUT ≥ VO(NOM) − 5% TYP 1.4 1.6 VON/OFF = 5 V –40°C ≤ TJ ≤ 125°C IO(PK) MIN 1.4 VON/OFF = 0 V ON/OFF input current MAX High = O/P ON –40°C ≤ TJ ≤ 125°C Low = O/P OFF –40°C ≤ TJ ≤ 125°C ION/OFF LP2981I-XX (2) 15 150 mA The ON/OFF inputs must be properly driven to prevent misoperation. For details, see Operation With ON/OFF Control. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 Electrical Characteristics (continued) Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 1 mA, COUT = 1 μF, VON/OFF = 2 V.(1) PARAMETER en Output noise voltage (RMS) ΔVO/ΔVIN Ripple rejection IO(MAX) (5) Short-circuit current TEST CONDITIONS LP2981AI-XX (2) MIN TYP LP2981I-XX (2) MAX MIN TYP MAX UNIT BW = 300 Hz to 50 kHz COUT = 10 μF 160 160 μV ƒ = 1 kHz, COUT = 10 μF 63 63 dB 150 150 mA RL = 0 Ω (steady state) (5) See related curve(s) in Typical Characteristics section. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 7 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 www.ti.com 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. 5-V Output Voltage vs Temperature Figure 2. 3.3-V Output Voltage vs Temperature Figure 3. 3-V Output Voltage vs Temperature Figure 4. 5-V Dropout Characteristics Figure 5. 3.3-V Dropout Characteristics 8 Submit Documentation Feedback Figure 6. 3-V Dropout Characteristics Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 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 7. Dropout Voltage vs Temperature Figure 8. Dropout Voltage vs Load Current Figure 9. Ground Pin Current vs Temperature Figure 10. Ground Pin Current vs Load Current Figure 11. Input Current vs VIN Figure 12. Input Current vs VIN Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 9 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 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. 10 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: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 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 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 Figure 24. Ripple Rejection Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 11 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 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. 12 Figure 25. Output Noise Density Figure 26. Output Impedance vs Frequency Figure 27. Input-to-Output Leakage vs Temperature Figure 28. Output Reverse Leakage vs Temperature Figure 29. Turnon Waveform Figure 30. Turnoff Waveform Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 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 31. ON/OFF Pin Current vs VON/OFF Figure 32. ON/OFF Threshold vs Temperature Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 13 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 www.ti.com 7 Detailed Description 7.1 Overview The LP2981-N is a 100-mA, fixed-output voltage regulator designed specifically to meet the requirements of battery-powered applications. Available in assorted output voltages from 2.5 V to 5 V, the device has an output tolerance of 0.75% for the A grade (1.25% for the non-A version). Using a VIP process, the LP2981-N contains these features to facilitate battery-powered designs: • Fixed 5-V, 3.6-V, 3.3-V, 3-V, and 2.5-V output versions • Very high-accuracy 1.23-V reference • Low-dropout voltage, typical dropout of 200 mV at 100-mA load current and 7 mV at 1-mA load • Low ground current, typically 600 μA at 100-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 LP2981-N provides multiple fixed output options from 2.5 V to 5 V. 7.3.2 High-Accuracy Output Voltage With special careful design to minimize all contributions to the output voltage error, the LP2981-N distinguishes itself as a very high-accuracy output voltage micropower LDO. This includes a tight initial tolerance (0.75% typical), extremely good line regulation (0.007%/V typical), and a very low output voltage temperature coefficient, making the part an ideal low-power voltage reference. 14 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 Feature Description (continued) 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-FET is fully on in the ohmic region of operation and is characterized by the classic RDS(ON) of the FET. 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. 7.3.4 Low Ground Current LP2981-N uses a vertical PNP process which allows for quiescent currents that are considerably lower than those associated with traditional lateral PNP regulators, typically 600 μA at 100-mA load and 80 μA at 1-mA load. 7.3.5 Sleep Mode When pulling the ON/OFF pin to low level, LP2981-N will enter 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 LP2981-N 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 LM2981-N 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. Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 15 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 www.ti.com 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 LP2981-N is a linear voltage regulator operating from 2.1 V to 16 V on the input and regulates voltages between 2.5 V to 5 V with 0.75% accuracy and 100-mA maximum output current. Efficiency is defined by the ratio of output voltage to input voltage because the LP2981-N 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 VIN IN VOUT OUT COUT CIN GND ON/OFF ON/OFF NC Copyright © 2016, Texas Instruments Incorporated *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). ***Do not make connections to this pin. Figure 33. LP2981-N Typical Application 8.2.1 Design Requirements PARAMETER DESIGN REQUIREMENT Input voltage 5 V ±10%, provided by the DC-DC converter switching at 1 MHz Output voltage 3.3 V ±5% Output current 100 mA (maximum), 1 mA (minimum) RMS noise, 300 Hz to 50 kHz < 1 mVRMS PSRR at 1 kHz > 40 dB 8.2.2 Detailed Design Procedure 8.2.2.1 External Capacitors Like any low-dropout regulator, the external capacitors used with the LP2981-N must be carefully selected to assure regulator loop stability. 16 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 8.2.2.1.1 Input Capacitor An input capacitor with a value ≥ 1 μF is required with the LP2981-N (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 LP2981-N 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 36, Figure 37, Figure 38, and Figure 39). 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 should be located not more than 0.5 inches from the OUT pin of the LP2981-N and returned to a clean analog ground. 8.2.2.2 Capacitor Characteristics 8.2.2.2.1 Tantalum Tantalum capacitors are the best choice for use with the LP2981-N. Most good quality tantalums can be used with the LP2981-N, 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 below for important information on ceramic capacitors). 8.2.2.2.2 Ceramic Ceramic capacitors are not recommended for use at the output of the LP2981-N. This is because the ESR of a ceramic can be low enough to go below the minimum stable value for the LP2981-N. 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 should 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 LP2981-N. 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 50x 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 LP2981-N 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 34). Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 17 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 www.ti.com LP2981-N VIN VOUT PNP GND Figure 34. LP2981-N 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. 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 35), to limit the reverse voltage across the LP2981-N to 0.3 V (see Absolute Maximum Ratings). SCHOTTKY DIODE LP2981-N VIN VOUT PNP GND Figure 35. Adding External Schottky Diode Protection 8.2.2.4 ON and OFF Input Operation The LP2981-N 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). 18 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 2016 The ON/OFF signal may come from either a totem-pole output, or an open-collector output with pullup resistor to the LP2981-N input voltage or another logic supply. The high-level voltage may exceed the LP2981-N 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 will not operate correctly if a slow-moving signal is applied to the ON/OFF input. 8.2.3 Application Curves Figure 36. 5-V, 3.3-μF ESR Curves Figure 37. 5-V, 10-μF ESR Curves Figure 38. 3-V, 3.3-μF ESR Curves Figure 39. 3-V, 10-μF ESR Curves Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N 19 LP2981-N SNOS773N – MARCH 2000 – REVISED APRIL 2016 www.ti.com 9 Power Supply Recommendations The LP2981-N is designed to operate from an input voltage supply range between 2.1 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 Input Capacitor VOUT IN GND OUT Output Capacitor Ground ON/OFF ON/OFF NC Figure 40. LP2981-N Layout Example 20 Submit Documentation Feedback Copyright © 2000–2016, Texas Instruments Incorporated Product Folder Links: LP2981-N LP2981-N www.ti.com SNOS773N – MARCH 2000 – REVISED APRIL 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 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. 11.3 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 11.4 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. 11.5 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: LP2981-N 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) LP2981AIM5-2.5/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0CA LP2981AIM5-3.0/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L05A LP2981AIM5-3.3 LIFEBUY SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L04A LP2981AIM5-3.3/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L04A Samples LP2981AIM5-3.6/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0JA Samples LP2981AIM5-5.0 LIFEBUY SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L03A LP2981AIM5-5.0/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L03A LP2981AIM5X-3.0/NOPB LIFEBUY SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L05A LP2981AIM5X-3.3/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L04A Samples LP2981AIM5X-3.6/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0JA Samples LP2981AIM5X-5.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L03A Samples LP2981IM5-2.5 NRND SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L0CB LP2981IM5-2.5/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0CB LP2981IM5-3.0/NOPB LIFEBUY SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L05B LP2981IM5-3.3 NRND SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L04B LP2981IM5-3.3/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L04B Samples LP2981IM5-3.6/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0JB Samples LP2981IM5-5.0 NRND SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L03B LP2981IM5-5.0/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L03B Samples LP2981IM5X-3.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L05B Samples Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 10-Dec-2022 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) LP2981IM5X-3.3/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L04B Samples LP2981IM5X-3.6/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L0JB Samples LP2981IM5X-5.0 NRND SOT-23 DBV 5 3000 Non-RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 L03B LP2981IM5X-5.0/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 L03B (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