3 MHz, 600 mA, Low Quiescent Current Buck with 300 mA LDO Regulator Data Sheet ADP2140 FEATURES TYPICAL APPLICATION CIRCUITS Input voltage range: 2.3 V to 5.5 V V = 3.6V IN1 LDO input (VIN2) 1.65 V to 5.5 V + C IN 10F ADP2140 Buck output voltage range: 1.0 V to 3.3 V 100k 10 1 VIN1 PGND 1H V = 1.2V LDO output voltage range: 0.8 V to 3.3 V OUT 9 2 PG PG SW Buck output current: 600 mA 8 3 + C EN1 EN1 AGND OUT 10F LDO output current: 300 mA 7 4 EN2 EN2 FB V = 1.8V OUT2 6 5 LDO quiescent current: 22 A with zero load VOUT2 VIN2 + C OUT2 Buck quiescent current: 20 A in PSM mode 1F Low shutdown current: <0.3 A Figure 1. ADP2140 with LDO Connected to VIN1 Low LDO dropout 110 mV 300 mA load High LDO PSRR V = 3.3V IN1 65 dB 10 kHz at V = 1.2 V OUT2 + C IN 10F 55 dB 100 kHz at V = 1.2 V ADP2140 OUT2 100k 10 1 VIN1 PGND Low noise LDO: 40 V rms at V = 1.2 V 1H OUT2 V = 1.8V OUT 9 2 PG PG SW Initial accuracy: 1% 8 3 + C EN1 EN1 AGND OUT Current-limit and thermal overload protection 10F 7 4 EN2 EN2 FB Power-good indicator V = 1.2V OUT2 6 5 VOUT2 VIN2 Optional enable sequencing C + OUT2 1F 10-lead 0.75 mm 3 mm 3 mm LFCSP package Figure 2. ADP2140 with LDO Connected to Buck Output APPLICATIONS Mobile phones Personal media players Digital camera and audio devices Portable and battery-powered equipment GENERAL DESCRIPTION The ADP2140 includes a high efficiency, low quiescent 600 mA ADP2140 includes a power-good pin, soft start, and internal stepdown dc-to-dc converter and a 300 mA LDO packaged in a compensation. Numerous power sequencing options are user- small 10-lead 3 mm 3 mm LFCSP. The total solution requires selectable through two enable inputs. In autosequencing mode, only four tiny external components. the highest voltage output enables on the rising edge of EN1. During logic controlled shutdown, the input disconnects from The buck regulator uses a proprietary high speed current- the output and draws less than 300 nA from the input source. mode, constant frequency, pulse-width modulation (PWM) Other key features include: undervoltage lockout to prevent deep control scheme for excellent stability and transient response. To battery discharge, soft start to prevent input current overshoot ensure the longest battery life in portable applications, the at startup, and both short-circuit protection and thermal overload ADP2140 has a power saving variable frequency mode to reduce protection circuits to prevent damage in adverse conditions. switching frequency under light loads. When the ADP2140 is used with two 0603 capacitors, one 0402 The LDO is a low quiescent current, low dropout linear regulator capacitor, one 0402 resistor, and one 0805 chip inductor, the as low as designed to operate in a split supply mode with VIN2 2 total solution size is approximately 90 mm resulting in the smallest 1.65 V. The low input voltage minimum allows the LDO to be footprint solution to meet a variety of portable applications. powered from the output of the buck regulator increasing effi- ciency and reducing power dissipation. The ADP2140 runs from input voltages of 2.3 V to 5.5 V allowing single Li+/Li polymer cell, multiple alkaline/NiMH cell, PCMCIA, and other standard power sources. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20102019 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 079 32 -002 07 93 2-00 1ADP2140 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Short-Circuit Protection ............................................................ 20 Applications ....................................................................................... 1 Undervoltage Lockout ............................................................... 20 Typical Application Circuits ............................................................ 1 Thermal Protection .................................................................... 20 General Description ......................................................................... 1 Soft Start ...................................................................................... 20 Revision History ............................................................................... 2 Current Limit .............................................................................. 20 Specif icat ions ..................................................................................... 3 Power-Good Pin ......................................................................... 20 Recommended Specifications: Capacitors and Inductor ........ 4 LDO Section ............................................................................... 20 Absolute Maximum Ratings ............................................................ 5 Applications Information .............................................................. 21 Thermal Data ................................................................................ 5 Power Sequencing ...................................................................... 21 Thermal Resistance ...................................................................... 5 Power-Good Function ............................................................... 24 ESD Caution .................................................................................. 5 External Component Selection ................................................ 24 Pin Configuration and Function Descriptions ............................. 6 Selecting the Inductor ................................................................ 24 Typical Performance Characteristics ............................................. 7 Output Capacitor ........................................................................ 24 Buck Output .................................................................................. 7 Input Capacitor ........................................................................... 24 LDO Output ................................................................................ 14 Efficiency ..................................................................................... 25 Theory of Operation ...................................................................... 19 Recommended Buck External Components .......................... 25 Buck Section ................................................................................ 19 LDO Capacitor Selection .......................................................... 26 Control Scheme .......................................................................... 19 LDO as a Postregulator to Reduce Buck Output Noise ........ 26 PWM Operation ......................................................................... 19 Thermal Considerations ................................................................ 28 PSM Operation ........................................................................... 19 PCB Layout Considerations ...................................................... 29 Pulse Skipping Threshold .......................................................... 19 Outline Dimensions ....................................................................... 30 Selected Features ............................................................................. 20 Ordering Guide .......................................................................... 30 REVISION HISTORY 10/2019Rev. A to Rev. B Changes to Output Capacitor Section ......................................... 24 Updated Outline Dimensions ....................................................... 30 Changes to Ordering Guide .......................................................... 30 9/2012Rev. 0 to Rev. A Updated Outline Dimensions ....................................................... 30 Changes to Ordering Guide .......................................................... 30 6/2010Revision 0: Initial Version Rev. B Page 2 of 32