Low Duty Cycle, 600 mA, 3 MHz, Synchronous Step-Down DC-to-DC Converter Data Sheet ADP2102 FEATURES TYPICAL APPLICATION CIRCUIT Input voltage range: 2.7 V to 5.5 V 600 mA maximum load current INPUT VOLTAGE OUTPUT VOLTAGE 95% efficiency L 2.7V TO 5.5V 1.2V OR 1.375V V LX IN Low duty cycle operation 1H C C IN OUT 2.2F 2.2F Only 3 tiny external ceramic components ADP2102 3 MHz typical operating frequency FORCED Fixed output voltage of 1.2 V or 1.375 V CCM MODE FB/OUT Adjustable output voltage up to 3.3 V EN GND 0.01 A shutdown supply current DCM/ Automatic power save mode CCM ON Internal synchronous rectifier OFF Internal soft start Internal compensation Enable/shutdown logic input Figure 1. Undervoltage lockout Current limit protection The ADP2102 is available in both fixed and adjustable output Thermal shutdown voltage options with a 600 mA maximum output current. The fixed Small 8-lead, 3 mm 3 mm LFCSP output voltage options are 1.2 V and 1.375 V. The adjustable output voltage options are available from 1.5 V to 3.3 V. The ADP2102 APPLICATIONS requires only three external components and consumes 0.01 A USB powered devices in shutdown mode. WLAN and gateways The ADP2102 is available in an 8-lead LFCSP and is specified Point of loads for the 40C to +85C temperature range. Processor core power from 5 V 100 Digital cameras V = 1.375V OUT V = 2.7V IN T = 25C PDAs and palmtop computers A 95 V = 3V IN Portable media players, GPS 90 GENERAL DESCRIPTION 85 V = 4.2V IN The ADP2102 is a synchronous step-down dc-to-dc converter V = 3.6V IN 80 that converts a 2.7 V to 5.5 V unregulated input voltage to a lower regulated output voltage with up to 95% efficiency and 1% 75 accuracy. The low duty cycle capability of the ADP2102 is ideal for 70 USB applications or 5 V systems that power up submicron subvolt processor cores. Its 3 MHz typical operating frequency and excel- 65 lent transient response allow the use of small, low cost 1 H 60 inductors and 2.2 F ceramic capacitors. At medium-to-high 10 100 1000 LOAD CURRENT (mA) load currents, it uses a current mode, pseudofixed frequency pulse- width modulation to extend battery life. To ensure the longest Figure 2. Efficiency vs. Load Current at VOUT = 1.375 V battery life in portable applications, the ADP2102 has a power save mode (PSM) that reduces the switching frequency under light load conditions to significantly reduce quiescent current. 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. 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Technical Support www.analog.com EFFICIENCY (%) 06631-052 06631-001ADP2102 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Soft Start ...................................................................................... 15 Applications ....................................................................................... 1 Enable........................................................................................... 15 General Description ......................................................................... 1 Undervoltage Lockout ............................................................... 15 Typical Application Circuit ............................................................. 1 Thermal Shutdown .................................................................... 15 Revision History ............................................................................... 2 Applications Information .............................................................. 16 Specifications ..................................................................................... 3 Inductor Selection ...................................................................... 16 Absolute Maximum Ratings ............................................................ 4 Input Capacitor Selection .......................................................... 16 Thermal Resistance ...................................................................... 4 Output Capacitor Selection....................................................... 16 Boundary Condition .................................................................... 4 Typical Application Circuits ..................................................... 17 ESD Caution .................................................................................. 4 Setting the Output Voltage ........................................................ 19 Pin Configuration and Function Descriptions ............................. 5 Efficiency Considerations ......................................................... 19 Typical Performance Characteristics ............................................. 6 Thermal Considerations ............................................................ 20 Theory of Operation ...................................................................... 13 Design Example .......................................................................... 20 Control Scheme .......................................................................... 13 Circuit Board Layout Recommendations ................................... 22 Constant On-Time Timer ......................................................... 13 Recommended Layout ............................................................... 22 Forced Continuous Conduction Mode ................................... 13 Outline Dimensions ....................................................................... 24 Power Save Mode ........................................................................ 13 Ordering Guide .......................................................................... 24 Synchronous Rectification ........................................................ 14 Current Limit .............................................................................. 14 REVISION HISTORY 7/2016Rev. B to Rev. C 9/2007Rev. A to Rev. B Changed ADP2102-ADJ to ADP2102 Adjustable Output Changes to Features Section, Applications Section, and General Voltage Options, ADP2102-FXD to ADP2102 Fixed Output Description Section ........................................................................... 1 Voltage Options, ADP2102-xx to ADP2102 Fixed Output Changes to Table 4 ............................................................................. 5 Voltage Options, and CP-8-2 to CP-8-13 ................... Throughout Changes to Table 6 .......................................................................... 17 Moved Figure 1 Renumbered Sequentially .................................. 1 Changes to Table 7 .......................................................................... 19 Changes to Circuit Board Layout Recommendations Section ...... 21 Changes to Features Section, General Description Section, and Figure 1 .............................................................................................. 1 Updated Outline Dimensions ....................................................... 23 Added Figure 2 Caption................................................................... 1 Changes to Ordering Guide .......................................................... 23 Changes to Table 1 ............................................................................ 3 Changes to Figure 3 and Table 4 ..................................................... 5 6/2007Rev. 0 to Rev. A Changes to Figure 47 and Figure 48 ............................................. 17 Changes to Ordering Guide .......................................................... 23 Changes to Figure 49 and Figure 50 ............................................. 18 Changes to Table 7 .......................................................................... 19 6/2007Revision 0: Initial Version Updated Outline Dimensions ....................................................... 24 Changes to Ordering Guide .......................................................... 24 Rev. C Page 2 of 24