Datasheet LTC3877 (Analog Devices) - 7

LTC3877
Typical perForMance characTerisTics Tracking Up and Down Current Sense Threshold with External Ramp INTVCC Line Regulation vs ITH Voltage
6 40 TK/SS1 ILIM = 0 35 TK/SS2 ILIM = 1/4 INTVCC 2V/DIV 5 30 ILIM = 1/2 INTVCC ILIM = 3/4 INTVCC ILIM = INTV 4 25 CC VOUT2 20 3 15 VOUT1 VOLTAGE (V) V CC 10 OUT1 V 2 OUT2 INTV 5 500mV/DIV 0 10ms/DIV 3877 G10 VIN = 12V 1 CURRENT SENSE THRESHOLD (mV) VOUT1 = 0.9V, 1Ω LOAD –5 VOUT2 = 1.2V, 1.5Ω LOAD 0 –10 0 5 10 15 20 25 30 35 40 0 0.5 1 1.5 2 INPUT VOLTAGE (V) ITH VOLTAGE (V) 3877 G11 3877 G12
Maximum Current Sense Threshold Maximum Current Sense Threshold vs Feedback Voltage Regulated Feedback Voltage vs Common Mode Voltage (Current Foldback) vs Temperature
35 35 603 ILIM = INTVCC ILIM = INTV 30 30 CC 602 ILIM = 3/4 INTVCC ILIM = 3/4 INTV 25 25 CC 601 ILIM = 1/2 INTVCC ILIM = 1/2 INTV 20 20 CC ILIM = 1/4 INTV 600 CC ILIM = 1/4 INTV 15 15 CC ILIM = GND ILIM = GND 599 10 10 FEEDBACK VOLTAGE (mV) 598 CURRENT SENSE THRESHOLD (mV) 5 5 0 MAXIMUM CURRENT SENSE THRESHOLD (mV) 0 597 0 1 2 3 4 0 0.1 0.2 0.3 0.4 0.5 0.6 –55–40–25–10 5 20 35 50 65 80 95 110125 VSENSE COMMON MODE VOLTAGE (V) FEEDBACK VOLTAGE (V) TEMPERATURE (°C) 3877 G13 3877 G14 3877 G15
Oscillator Frequency Oscillator Frequency TK/SS Pull-Up Current vs Temperature vs Input Voltage vs Temperature
1400 900 1.4 VFREQ = INTVCC 800 V 1200 FREQ = INTVCC 1.35 700 1000 600 1.3 800 500 VFREQ = 1.22V VFREQ = 1.22V 1.25 600 400 300 1.2 400 TK/SS CURRENT (µA) 200 OSCILLATOR FREQUENCY (kHz) OSCILLATOR FREQUENCY (kHz) 200 V 1.15 FREQ = GND V 100 FREQ = GND 0 0 1.1 –55 –40 –25 –10 5 20 35 50 65 80 95 110 125 0 5 10 15 20 25 30 35 40 –55–40–25–10 5 20 35 50 65 80 95 110125 TEMPERATURE (°C) INPUT VOLTAGE (V) TEMPERATURE (°C) 3877 G16 3877 G17 3877 G18 3877f For more information www.linear.com/LTC3877 7