Datasheet ADP2121 (Analog Devices) - 5

Data Sheet ADP2121 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS BALL A1 INDICATOR 1 2 MODE VIN A SW EN B FB GND C TOP VIEW (BALL SIDE DOWN)
003
(BUMPS ON OPPOSITE SIDE) Not to Scale
07407- Figure 3. Pin Configuration
Table 5. Pin Function Descriptions Pin No. Mnemonic Description
A1 MODE Mode Select. This pin toggles between auto mode (PFM and PWM switching) and PWM mode. Set MODE low to allow the part to operate in auto mode. Pull MODE high to force the part to operate in PWM mode. The voltage applied to MODE must never be higher than the voltage applied to VIN. Do not leave this pin floating. B1 SW Switch Node. C1 FB Feedback Divider Input. Connect the output capacitor from FB to GND as close as possible to the ADP2121 to set the output voltage ripple and to complete the control loop. A2 VIN Power Supply Input. Connect the input capacitor from VIN to GND as close as possible to the ADP2121. B2 EN Enable. Pull this pin high to enable the part. Set this pin low to disable the part. Do not leave this pin floating. C2 GND Ground Pin. Rev. C | Page 5 of 20 Document Outline FEATURES APPLICATIONS TYPICAL APPLICATION CIRCUIT GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL DATA THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION OVERVIEW MODE SELECTION Pulse-Width Modulation (PWM) Mode Auto Mode (PFM and PWM Switching) Pulse Frequency Modulation (PFM) Mode Transition ENABLE/SHUTDOWN INTERNAL CONTROL FEATURES Overcurrent Protection Soft Start Synchronous Rectification Compensation Undervoltage Lockout (UVLO) Output Short-Circuit Protection Thermal Shutdown (TSD) Protection APPLICATIONS INFORMATION INDUCTOR SELECTION INPUT CAPACITOR SELECTION OUTPUT CAPACITOR SELECTION PCB LAYOUT GUIDELINES OUTLINE DIMENSIONS ORDERING GUIDE