Datasheet LTC1877 (Analog Devices) - 4

LTC1877
TYPICAL PERFORMANCE CHARACTERISTICS Oscillator Frequency Effi ciency vs Output Current Reference Voltage vs Temperature vs Temperature
95 0.814 605 V V IN = 3.6V VIN = 5V IN = 5V 90 595 0.809 585 85 VIN = 10V 575 80 VIN = 7.2V 0.804 565 VIN = 5V 75 555 0.799 70 545 EFFICIENCY (%) 535 65 0.794 FREQUENCY (kHz) 525 60 REFERENCE VOLTAGE (V) 0.789 515 55 L = 10μH 505 VOUT = 2.5V 50 0.784 495 0.1 1.0 10 100 1000 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 OUTPUT CURRENT (mA) TEMPERATURE (°C) TEMPERATURE (°C) 1877 G04 1877 G05 1877 G06
Oscillator Frequency vs Supply Voltage Output Voltage vs Load Current RDS(ON) vs Input Voltage
605 2.53 1.2 PULSE-SKIPPING MODE 595 2.52 VIN = 4.2V 585 1.0 2.51 L = 10μH 575 2.50 SYNCHRONOUS 0.8 565 SWITCH 2.49 555 TAGE (V) (Ω) 2.48 0.6 545 2.47 DS(ON) MAIN SWITCH R 535 2.46 0.4 525 OUTPUT VOL 2.45 OSCILLATOR FREQUENCY (kHz) 515 0.2 505 2.44 495 2.43 0 0 2 4 6 8 10 12 0 200 400 600 800 0 1 2 3 4 5 6 7 8 9 10 SUPPLY VOLTAGE (V) LOAD CURRENT (mA) INPUT VOLTAGE (V) 1877 G07 1877 G08 1877 G09
RDS(ON) vs Temperature DC Supply Current vs Input Voltage DC Supply Current vs Temperature
1.4 250 300 VIN = 5V PULSE-SKIPPING MODE 1.2 250 PULSE-SKIPPING MODE 200 V A) μ 1.0 OUT = 1.8V 200 V 150 (Ω) IN = 3V 0.8 150 Y CURRENT (μA) DS(ON)R VIN = 5V 100 0.6 100 SUPPLY CURRENT ( DC SUPPL 50 0.4 SYNCHRONOUS SWITCH 50 MAIN SWITCH Burst Mode OPERATION Burst Mode OPERATION 0.2 0 0 –50 –25 0 25 50 75 100 125 0 2 4 6 8 10 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) INPUT VOLTAGE (V) TEMPERATURE (°C) 1877 G10 1877 G11 1877 G11b 1877fb 4