Datasheet LTC3836 (Analog Devices) - 4

LTC3836
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Load Step Load Step Effi ciency vs Load Current (Forced Continuous Mode) (Pulse-Skipping Mode)
100 90 V V OUT OUT AC COUPLED AC COUPLED 80 100mV/DIV 100mV/DIV PULSE-SKIPPING 70 MODE 60 INDUCTOR INDUCTOR FORCED CURRENT CURRENT 50 CONTINUOUS EFFICIENCY (%) 5A/DIV 5A/DIV MODE 40 V V 100 30 SYNC/FCB = V IN = 3.6V 100μs/DIV 3836 G02 IN = 3.6V μs/DIV 3836 G03 IN V V SYNC/FCB = 0V OUT = 1.8V OUT = 1.8V CONTINUOUS MODE: 400mA TO 4A PULSE-SKIPPING MODE: 400MA TO 4A 20 1 10 100 1000 10000 CIRCUIT OF FIGURE 15 CIRCUIT OF FIGURE 15 LOAD CURRENT (mA) V 3836 G01 IN = 3.3V VOUT = 1.5V CIRCUIT OF FIGURE 15
Light Load Light Load Tracking Start-Up with Internal (Pulse-Skipping Mode) (Forced Continuous Mode) Soft-Start (CRUN/SS = 0μF)
VOUT1 VSW VSW 1.8V 2V/DIV 2V/DIV V V OUT OUT 20mV/DIV 20mV/DIV VOUT2 AC COUPLED AC COUPLED 1.2V 500mV/DIV INDUCTOR INDUCTOR CURRENT CURRENT 5A/DIV 5A/DIV V 2 3836 G04 IN = 3.6V μs/DIV V 2 IN = 3.6V μs/DIV 3836 G05 VIN = 3.6V 250μs/DIV 3836 G06 VOUT = 1.8V VOUT = 1.8V RLOAD1 = RLOAD2 = 1Ω ILOAD = 300mA ILOAD = 300mA CIRCUIT OF FIGURE 15 CIRCUIT OF FIGURE 15 CIRCUIT OF FIGURE 15
Tracking Start-Up with External Oscillator Frequency Soft-Start (C Sequential Start-Up RUN/SS = 0.01μF) vs Input Voltage
5 4 VOUT1 VOUT1 1.8V 1.8V 3 2 VOUT2 V 1 OUT2 1.2V 1.2V 0 500mV/DIV 500mV/DIV –1 –2 –3 VIN = 3.6V 2.50ms/DIV 3836 G07 VIN = 3.3V 4ms/DIV 3836 G10 R NORMALIZED FREQUENCY SHIFT (%) R –4 LOAD1 = RLOAD2 = 1Ω LOAD1 = RLOAD2 = 1Ω CIRCUIT OF FIGURE 15 VOUT1: INTERNAL SOFT-START –5 VOUT2: CTRACK/SS = 0.047μF 2.5 3.0 3.5 4.0 4.5 CIRCUIT OF FIGURE 15 INPUT VOLTAGE (V) 3836 G08 3836fb 4 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS FUNCTIONAL DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY RELATED PARTS