Datasheet ADP1821 (Analog Devices) - 4

ADP1821 Parameter Conditions Min Typ Max Unit
LOGIC THRESHOLDS (SHDN, SYNC, FREQ) SHDN, SYNC, FREQ Input High Voltage VVCC = 3.7 V to 5.5 V 2.0 V SHDN, SYNC, FREQ Input Low Voltage VVCC = 3.7 V to 5.5 V 0.8 V SYNC, FREQ Input Leakage Current SYNC = FREQ = GND 0.1 1 μA SHDN Pull-Down Resistance 100 kΩ THERMAL SHUTDOWN Thermal Shutdown Threshold 145 °C Thermal Shutdown Hysteresis 10 °C PWGD OUTPUT FB Overvoltage Threshold VFB rising 750 mV FB Overvoltage Hysteresis 35 mV FB Undervoltage Threshold VFB rising 550 mV FB Undervoltage Hysteresis 35 mV PWGD Off Current VPWGD = 5 V 1 μA PWGD Low Voltage IPWGD = 10 mA 150 500 mV Rev. C | Page 4 of 24 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION SIMPLIFIED BLOCK DIAGRAM PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION SOFT START ERROR AMPLIFIER CURRENT-LIMIT SCHEME MOSFET DRIVERS INPUT VOLTAGE RANGE SETTING THE OUTPUT VOLTAGE SWITCHING FREQUENCY CONTROL AND SYNCHRONIZATION COMPENSATION POWER-GOOD INDICATOR THERMAL SHUTDOWN SHUTDOWN CONTROL APPLICATION INFORMATION SELECTING THE INPUT CAPACITOR OUTPUT LC FILTER SELECTING THE MOSFETS SETTING THE CURRENT LIMIT FEEDBACK VOLTAGE DIVIDER COMPENSATING THE VOLTAGE MODE BUCK REGULATOR Type II Compensator Type III Compensator SETTING THE SOFT START PERIOD PCB LAYOUT GUIDELINE RECOMMENDED COMPONENT MANUFACTURERS APPLICATION CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE