Datasheet ADP1821 (Analog Devices) - 7

ADP1821 TYPICAL PERFORMANCE CHARACTERISTICS 97 0.6003 TA = 25°C 96 FREQUENCY = 300kHz 3.3V OUTPUT 0.6002 95 ) V 94 ( 0.6001 ) E (% 93 AG Y T 0.6000 C L O 92 1.8V OUTPUT IEN V IC F 0.5999 91 EF DBACK 90 E E 0.5998 F 89 0.5997 88 87 0.5996 0 2 4 6 8 10 12 14 16
5 8 00
–50 –30 –10 10 30 50 70 90 110
00 0- 0-
LOAD CURRENT (A)
31
TEMPERATURE (°C)
31 05 05 Figure 5. Efficiency vs. Load Current, VIN = 5 V, VOUT = 3.3 V, 1.8 V Figure 8. FB Regulation Voltage vs. Temperature
94 700 TA = 25°C FREQUENCY = 300kHz 92 600 ) 3.3V OUTPUT kHz 600kHz 90 ( 500 ) Y NC (% Y 88 UE 400 C 1.8V OUTPUT Q IEN RE IC F F 86 300 NG 300kHz EF 84 CHI IT 200 W S 82 100 80 0 0 2 4 6 8 10 12 14 16
6 9 00
–50 0 50 100
00 0- 0-
LOAD CURRENT (A)
31
TEMPERATURE (°C)
31 05 05 Figure 6. Efficiency vs. Load Current, VIN = 12 V, VOUT = 3.3 V, 1.8 V Figure 9. Switching Frequency vs. Temperature
1400 1200 OUTPUT VOLTAGE (20mV/DIV) 1000 A) µ ( T N 800 RRE 600 CC CU V 400 LOAD CURRENT (5A/DIV) 200 0 0 1 2 3 4 5 6
7 10 00 -0 0- 10
VCC VOLTAGE (V)
31 53 05 0 Figure 7. VCC Supply Current vs. VCC Voltage Figure 10. Load Transient Response, 1.5 A to 15 A Rev. C | Page 7 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