Datasheet ADP2102 (Analog Devices) - 9

Data Sheet ADP2102 4.5 400 TA = 25°C 350 4.0 ) ) Hz PMOS SWITCH M 1.25V 300 ( (mΩ 1.2V 3.5 1V NCY 0.8V 250 UE Q 3.0 SISTANCE 200 RE RE F N NG O 150 NMOS SWITCH 2.5 CHI IT ITCH 1.5V 1.375V 100 W S 1.8V SW 2.0 1.875V 50 1.5 0
051
0 100 200 300 400 500 600 –40 –20 0 20 40 60 80 100 120
054
LOAD CURRENT (mA)
06631-
TEMPERATURE (°C)
06631- Figure 22. Switching Frequency vs. Load Current Figure 25. Switch On Resistance vs. Temperature
1.08 T T T A = 25°C A = 25°C 1.07 CH4: LX 1.06 A) ( 1.05 4 IT IM L 1.04 NT CH1: IL 1.03 1 CURRE CH2: V 1.02 OUT 1.01 2 1.00 2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8 5.1 5.4 5.7
029
CH1 500mA Ω B B W CH2 2.00V W M 1.00µs A CH4 2.76V
014
INPUT VOLTAGE (V) CH4 2.00V BW
06631-
T 51.00%
06631-

Figure 23. Valley Current Limit Figure 26. PSM Mode Operation at Very Light Loads (10 mA)
400 T TA = 25°C TA = 25°C 350 ) PSM CCM PSM CH1: V 300 OUT (mΩ PMOS SWITCH 250 1 SISTANCE 200 RE N O 150 NMOS SWITCH CH3: IL ITCH 100 SW 50 3 0
022
2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8 5.1 5.4
027
CH1 50.0mV BW M 100µs A CH3 86.0mA INPUT VOLTAGE (V) CH3 50.0mA Ω BW
06631- 06631- Figure 24. Switch On Resistance vs. Input Voltage Figure 27. PSM Mode Entry—Exit Operation (10 mA to 50 mA to 10 mA) Rev. C | Page 9 of 24 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TYPICAL APPLICATION CIRCUIT REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE BOUNDARY CONDITION ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CONTROL SCHEME CONSTANT ON-TIME TIMER FORCED CONTINUOUS CONDUCTION MODE POWER SAVE MODE SYNCHRONOUS RECTIFICATION CURRENT LIMIT SOFT START ENABLE UNDERVOLTAGE LOCKOUT THERMAL SHUTDOWN APPLICATIONS INFORMATION INDUCTOR SELECTION INPUT CAPACITOR SELECTION OUTPUT CAPACITOR SELECTION TYPICAL APPLICATION CIRCUITS SETTING THE OUTPUT VOLTAGE EFFICIENCY CONSIDERATIONS Power Switch Conduction Losses Inductor Losses Switching Losses Transition Losses THERMAL CONSIDERATIONS DESIGN EXAMPLE Inductor Output Capacitor Input Capacitor Losses CIRCUIT BOARD LAYOUT RECOMMENDATIONS RECOMMENDED LAYOUT OUTLINE DIMENSIONS ORDERING GUIDE