ADP2121Data SheetOUTPUT VOLTAGE (50mV/DIV)OUTPUT VOLTAGE (50mV/DIV)LOAD CURRENT (100mA/DIV)LOAD CURRENT (100mA/DIV) 8 25 0 -02 7 07- 40 74 TIME (20µs/DIV)TIME (20µs/DIV) 0 07 Figure 28. Load Transient Response, 0 mA to 150 mA Figure 31. Load Transient Response, 50 mA to 250 mA (VIN = 2.5 V, PWM Mode) (VIN = 2.5 V, Auto Mode) OUTPUT VOLTAGE (50mV/DIV)OUTPUT VOLTAGE (50mV/DIV)LOAD CURRENT (100mA/DIV)LOAD CURRENT (100mA/DIV) 6 9 -02 -02 7 7 40 TIME (20µs/DIV) 40 TIME (20µs/DIV) 07 07 Figure 29. Load Transient Response, 0 mA to 150 mA Figure 32. Load Transient Response, 50 mA to 250 mA (VIN = 3.6 V, PWM Mode) (VIN = 3.6 V Auto Mode) OUTPUT VOLTAGE (50mV/DIV)OUTPUT VOLTAGE (50mV/DIV, 1.82V OFFSET)LOAD CURRENT (100mA/DIV)LOAD CURRENT (100mA/DIV) 7 0 -02 -03 7 7 40 TIME (20µs/DIV) 40 TIME (20µs/DIV) 07 07 Figure 30. Load Transient Response, 0 mA to 150 mA Figure 33. Load Transient Response, 50 mA to 250 mA (VIN = 4.5 V, PWM Mode) (VIN = 4.5 V, Auto Mode) Rev. C | Page 10 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
