Datasheet ADP2442 (Analog Devices) - 7

Data Sheet ADP2442 TYPICAL PERFORMANCE CHARACTERISTICS EFFICIENCY IN FORCED FIXED FREQUENCY MODE 100 100 90 90 80 80 VIN = 12V 70 70 VIN = 12V 60 (%) 60 CY (%) VIN = 24V CY V N IN = 24V 50 N IE 50 IE 40 40 EFFIC EFFIC 30 30 20 20 VOUT = 3.3V VOUT = 3.3V 10 fSW = 300kHz 10 fSW = 700kHz 0 0 0.01 0.1 1
104
0.01 0.1 1
105
LOAD (A)
10667-
LOAD (A)
10667- Figure 4. Efficiency vs. Load Current, VOUT = 3.3 V, fSW = 300 kHz Figure 7. Efficiency vs. Load Current, VOUT = 3.3 V, fSW = 700 kHz
100 100 90 VIN = 12V 90 VIN = 12V 80 80 VIN = 24V 70 70 V V 60 IN = 36V 60 IN = 24V CY (%) CY (%) N 50 N IE 50 IE VIN = 36V 40 40 EFFIC EFFIC 30 30 20 20 VOUT = 5V VOUT = 5V 10 fSW = 300kHz 10 fSW = 700kHz 0 0 0.01 0.1 1
106
0.01 0.1 1
107
LOAD (A)
10667-
LOAD (A)
10667- Figure 5. Efficiency vs. Load Current, VOUT = 5 V, fSW = 300 kHz Figure 8. Efficiency vs. Load Current, VOUT = 5 V, fSW = 700 kHz
100 100 VIN = 24V 90 VIN = 24V 90 80 80 70 70 V V IN = 36V IN = 36V 60 60 CY (%) CY (%) N 50 N IE 50 IE 40 40 EFFIC EFFIC 30 30 20 20 V V 10 OUT = 12V OUT = 12V f 10 SW = 300kHz fSW = 600kHz 0 0 0.01 0.1 1
108
0.01 0.1 1
109
LOAD (A)
10667-
LOAD (A)
10667- Figure 6. Efficiency vs. Load Current, VOUT = 12 V, fSW = 300 kHz Figure 9. Efficiency vs. Load Current, VOUT = 12 V, fSW = 600 kHz Rev. B | Page 7 of 36 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TYPICAL CIRCUIT CONFIGURATION REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS EFFICIENCY IN FORCED FIXED FREQUENCY MODE EFFICIENCY IN PULSE SKIP MODE INTERNAL BLOCK DIAGRAM THEORY OF OPERATION CONTROL ARCHITECURE Fixed Frequency Mode Pulse Skip Mode ADJUSTABLE FREQUENCY POWER GOOD MODE OF OPERATION EXTERNAL SYNCHRONIZATION SOFT START UNDERVOLTAGE LOCKOUT PRECISION ENABLE/SHUTDOWN CURRENT-LIMIT AND SHORT-CIRCUIT PROTECTION THERMAL SHUTDOWN APPLICATIONS INFORMATION ADIsimPOWER DESIGN TOOL SELECTING THE OUTPUT VOLTAGE SETTING THE SWITCHING FREQUENCY EXTERNAL COMPONENT SELECTION Input Capacitor Selection Inductor Selection Output Capacitor Selection BOOST CAPACITOR VCC CAPACITOR LOOP COMPENSATION LARGE SIGNAL ANALYSIS OF THE LOOP COMPENSATION DESIGN EXAMPLE CONFIGURATION AND COMPONENTS SELECTION Resistor Divider Switching Frequency Inductor Selection Input Capacitor Selection Output Capacitor Selection Compensation Selection SYSTEM CONFIGURATION TYPICAL APPLICATION CIRCUITS DESIGN EXAMPLE OTHER TYPICAL CIRCUIT CONFIGURATIONS POWER DISSIPATION AND THERMAL CONSIDERATIONS POWER DISSIPATION Inductor Losses Power Switch Conduction Losses Switching Losses Transition Losses THERMAL CONSIDERATIONS EVALUATION BOARD THERMAL PERFORMANCE CIRCUIT BOARD LAYOUT RECOMMENDATIONS OUTLINE DIMENSIONS ORDERING GUIDE