ON PWM OFF AUTO 600 mA, 6 MHz, Synchronous Step-Down DC-to-DC Converter Data Sheet ADP2121 FEATURES TYPICAL APPLICATION CIRCUIT Peak efficiency: 92% OUTPUT VOLTAGE INPUT VOLTAGE* ADP2121 2.3V TO 5.5V L 1.8V, 1.82V, 1.85V, 1.875V, 2.3V Operating frequency: 6 MHz A2 VIN SW B1 0.47H C IN Typical quiescent current in auto mode: 36 A 2.2F Fixed output voltage: 1.8 V, 1.82 V, 1.85 V, 1.875 V, 2.3 V C1 C2 GND FB C OUT 4.7F Maximum guaranteed load current: 600 mA at V = 2.7 V to 5.5 V IN EN MODE B2 A1 Input voltage: 2.3 V to 5.5 V Typical shutdown supply current: 0.3 A Automatic power-saving mode *FOR OUTPUT VOLTAGE = 2.3 V, INPUT VOLTAGE = 2.9 V TO 5.5V. Compatible with tiny multilayer inductors Figure 1. Internal synchronous rectifier 95 AUTO MODE Internal compensation V = 2.7 V IN (V = 2.9V FOR V = 2.3V) IN OUT Internal soft start 85 Output to ground short-circuit protection Cycle-by-cycle current-limit protection Enable/shutdown logic input 75 Undervoltage lockout Thermal shutdown protection 2 Ultrasmall 6-ball, 0.4 mm pitch, 1.17 mm WLCSP 65 V = 1.8V OUT V = 1.82V OUT V = 1.85V OUT APPLICATIONS V = 1.875V OUT V = 2.3V OUT 55 Mobile phones 0.1 1 10 100 1000 LOAD CURRENT (mA) Digital cameras Digital audio Figure 2. Efficiency vs. Load Current for Each Voltage Option Portable equipment GENERAL DESCRIPTION The ADP2121 has an input voltage range of 2.3 V to 5.5 V (2.9 V The ADP2121 is a high frequency, low quiescent current to 5.5 V for VOUT = 2.3 V), allowing the use of a single Li+/Li step-down dc-to-dc converter optimized for portable applications polymer cell, 3-cell alkaline or Ni-MH cell, and other standard in which board area and battery life are critical constraints. The power sources. The converter can source up to 600 mA and is 6 MHz operating frequency enables the use of tiny ceramic induc- internally compensated to minimize external components. Other tors and capacitors. Additionally, the synchronous rectification key features, such as cycle-by-cycle peak current limit, soft start, improves efficiency and results in fewer external components. undervoltage lockout (UVLO), output-to-ground short-circuit At high load currents, the device uses a voltage regulating pulse- protection, and thermal shutdown, protect the internal and width modulation (PWM) mode that maintains a constant external circuit components. frequency with excellent stability and transient response. In forced PWM mode, the converter continues operating in PWM for light Table 1. Output Voltage Options loads. At light load conditions in auto mode, the ADP2121 can Input Voltage Typical Start-Up Fixed Output automatically enter a power-saving mode that uses pulse-frequency Range (V) Time (s) Voltage (V) modulation (PFM) to reduce the effective switching frequency and 2.3 to 5.5 75 1.8, 1.85, 1.875 ensure the longest battery life in portable applications. During logic 2.3 to 5.5 275 1.82 controlled shutdown (EN 0.4 V), the input is disconnected 2.9 to 5.5 100 2.3 from the output and draws less than 0.3 A current (typical) from the source. Rev. C 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 20092017 Analog Devices, Inc. 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Technical Support www.analog.com EFFICIENCY (%) 07407-062 07407-001ADP2121 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Overview ..................................................................................... 14 Applications ....................................................................................... 1 Mode Selection ........................................................................... 14 Typical Application Circuit ............................................................. 1 Enable/Shutdown ....................................................................... 15 General Description ......................................................................... 1 Internal Control Features .......................................................... 15 Revision History ............................................................................... 2 Applications Information .............................................................. 17 Specif icat ions ..................................................................................... 3 Inductor Selection ...................................................................... 17 Absolute Maximum Ratings ............................................................ 4 Input Capacitor Selection .......................................................... 17 Thermal Data ................................................................................ 4 Output Capacitor Selection ....................................................... 17 Thermal Resistance ...................................................................... 4 PCB Layout Guidelines .................................................................. 19 ESD Caution .................................................................................. 4 Outline Dimensions ....................................................................... 20 Pin Configuration and Function Descriptions ............................. 5 Ordering Guide .......................................................................... 20 Typical Performance Characteristics ............................................. 6 Theory of Operation ...................................................................... 14 REVISION HISTORY 9/2017Rev. B to Rev. C Changes to Figure 10 to Figure 12 Added Figure 13 to Figure 15 ... 7 Updated Outline Dimensions ....................................................... 20 Changes to Figure 16, Figure 17, Figure 19, and Figure 20.......... 8 Changes to Figure 22 Added Figure 23 and Figure 24 ................ 9 Changes to Ordering Guide .......................................................... 20 Added Figure 40, Figure 42, Figure 43, and Figure 45 .............. 12 1/2011Rev. A to Rev. B Added Figure 46 and Figure 48 Changes to Figure 47 ............. 13 Changes to Table 2 Summary .......................................................... 3 Changes to Figure 51 and the Overview Section ....................... 14 Changes to Undervoltage Lockout Threshold Parameter and Changes to the Auto Mode (PFM and PWM Switching) Section, Output Voltage Accuracy Parameter in Table 2 ........................... 3 Figure 53, the Mode Transition Section, and the Enable/ Shutdown Section ........................................................................... 15 6/2010Rev. 0 to Rev. A Changes to the Output Short-Circuit Protection Section and Changes to Features, General Description, Figure 1, and Figure 55 .......................................................................................... 16 Figure 2 Added Table 1 Renumbered Sequentially .................... 1 Changes to the Output Capacitor Selection Section ................. 17 Changes to Table 2 ............................................................................ 3 Changes to Table 6, Table 7, and Table 8 ..................................... 18 Changes to Table 3 ............................................................................ 4 Changes to Ordering Guide .......................................................... 20 Change to Typical Performance Characteristics Condition Statement Reorganized Typical Performance Characteristics 4/2009Revision 0: Initial Version Section Changes to Figure 4, Figure 6, Figure 7, and Figure 9 Added Figure 5 and Figure 8 Renumbered Sequentially ........... 6 Rev. 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