LM2705_07 NSC | Alldatasheet

Document overview

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Technical content

Features

■ 150mA, 0.7Ω, internal switch ■ Uses small surface mount components ■ Adjustable output voltage up to 20V ■ 2.2V to 7V input range ■ Input undervoltage lockout ■ 0.01µA shutdown current ■ Small 5-Lead SOT-23 package

Applications

■ LCD Bias Supplies ■ White LED Back-Lighting ■ Handheld Devices ■ Digital Cameras ■ Portable Applications Typical Application Circuit 20039701 FIGURE 1. Typical 20V Application

TJmax = 125°C, θJA = 220°C/W (Note 2)

Ordering Information

Order Number Package Type NSC Package Drawing Top Mark Supplied As LM2705MF-ADJ SOT23-5 MA05B S59B 1000 Units, Tape and Reel LM2705MFX-ADJ SOT23-5 MA05B S59B 3000 Units, Tape and Reel Pin Descriptions/Functions Pin Name Function 1 SW Power Switch input. 2 GND Ground. 3 FB Output voltage feedback input. 4 SHDN Shutdown control input, active low. 5 VIN Analog and Power input. SW(Pin 1): Switch Pin. This is the drain of the internal NMOS power switch. Minimize the metal trace area connected to this pin to minimize EMI. GND(Pin 2): Ground Pin. Tie directly to ground plane. FB(Pin 3): Feedback Pin. Set the output voltage by selecting values for R1 and R2 using: Connect the ground of the feedback network to an AGND plane which should be tied directly to the GND pin. SHDN(Pin 4): Shutdown Pin. The shutdown pin is an active low control. Tie this pin above 1.1V to enable the device. Tie this pin below 0.3V to turn off the device. VIN(Pin 5): Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. www.national.com 2 LM2705

Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN 7.5V SW Voltage 21V FB Voltage 2V SHDN Voltage 7.5V Maximum Junction Temp. TJ (Note 2) 150°C Lead Temperature (Soldering 10 sec.) 300°C Vapor Phase (60 sec.) 215°C Infrared (15 sec.) 220°C ESD Ratings (Note 3) Human Body Model Machine Model (Note 4) 2kV 200V Operating Conditions Junction Temperature (Note 5) −40°C to +125°C Supply Voltage 2.2V to 7V SW Voltage Max. 20.5V

Electrical Characteristics

Specifications in standard type face are for TJ = 25°C and those in boldface type apply over the full Operating Temperature Range (TJ = −40°C to +125°C). Unless otherwise specified VIN =2.2V. Symbol Parameter Conditions Min (Note 5) Typ (Note 6) Max (Note 5) Units IQ Device Disabled FB = 1.3V 40 70 µADevice Enabled FB = 1.2V 235 300 Shutdown SHDN = 0V 0.01 2.5 VFB FeedbackTrip Point 1.189 1.237 1.269 V ICL Switch Current Limit 110 100 150 175 180 mA IB FB Pin Bias Current FB = 1.23V (Note 7) 30 120 nA VIN Input Voltage Range 2.2 7.0 V RDSON Switch RDSON 0.7 1.6 Ω TOFF Switch Off Time 400 ns ISD SHDN Pin Current SHDN = VIN, TJ = 25°C 0 80 nASHDN = VIN, TJ = 125°C 15 SHDN = GND 0 IL Switch Leakage Current VSW = 20V 0.05 5 µA UVP Input Undervoltage Lockout ON/OFF Threshold 1.8 V VFB Hysteresis Feedback Hysteresis 8 mV SHDN Threshold SHDN low 0.7 0.3 VSHDN High 1.1 0.7 θJA SOT23-5 Thermal Resistance 220 °C/W Note 1: Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to be functional, but device parameter specifications may not be guaranteed. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, θJA, and the ambient temperature, TA. See the Electrical Characteristics table for the thermal resistance. The maximum allowable power dissipation at any ambient temperature is calculated using: PD (MAX) = (TJ(MAX) − TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature. Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each pin. Note 4: ESD susceptibility using the machine model is 150V for SW pin. Note 5: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are 100% production tested or guaranteed through statistical analysis. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL). Note 6: Typical numbers are at 25°C and represent the most likely norm. Note 7: Feedback current flows into the pin. 3 www.national.com LM2705

Typical Performance Characteristics Enable Current vs VIN (Part Switching) 20039705 Disable Current vs VIN (Part Not Switching) 20039706 Efficiency vs Load Current 20039724 Efficiency vs Load Current 20039725 SHDN Threshold vs VIN 20039713 Switch Current Limit vs VIN 20039737 www.national.com 4 LM2705

FB Trip Point and FB Pin Current vs Temperature 20039723 Output Voltage vs Load Current 20039727 Off Time vs Temperature 20039741 Step Response 20039728 VOUT = 20V, VIN = 3.0V 1) Load, 0.5mA to 5mA to 0.5mA, DC 2) VOUT, 200mV/div, AC 3) IL, 100mA/div, DC T = 100µs/div Start-Up/Shutdown 20039729 VOUT = 20V, VIN = 3.0V 1) SHDN, 1V/div, DC 2) IL, 100mA/div, DC 3) VOUT, 10V/div, DC T = 400µs/div RL = 3.9kΩ 5 www.national.com LM2705

Physical Dimensions inches (millimeters) unless otherwise noted 5-Lead Small Outline Package (M5) For Ordering, Refer to Ordering Information Table 11 www.national.com LM2705

LM2705 Micropower Step-up DC/DC Converter with 150mA Peak Current Limit THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS, IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT NATIONAL’S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS. EXCEPT AS PROVIDED IN NATIONAL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other brand or product names may be trademarks or registered trademarks of their respective holders. Copyright© 2007 National Semiconductor Corporation For the most current product information visit us at www.national.com National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 National Semiconductor Europe Customer Support Center Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +49 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: ap.support@nsc.com National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 www.national.com