Datasheet LTC3858-2 (Analog Devices) - 5
| Manufacturer | Analog Devices |
| Description | Low IQ, Dual 2-Phase Synchronous Step-Down Controller |
| Pages / Page | 40 / 5 — TYPICAL PERFORMANCE CHARACTERISTICS. Efficiency and Power Loss vs Output … |
| File Format / Size | PDF / 448 Kb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Efficiency and Power Loss vs Output Current. Efficiency vs Output Current
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LTC3858-2
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10000 100 98 FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT 90 V 90 IN = 12V 96 VOUT = 3.3V V V IN = 5V OUT = 3.3V I 80 1000 80 OUT = 4A 94 POWER LOSS (mW) 70 70 VIN = 12V 92 60 100 60 90 50 50 Burst Mode 88 40 OPERATION 10 40 EFFICIENCY (%) PULSE- EFFICIENCY (%) EFFICIENCY (%) 86 30 SKIPPING 30 MODE 84 20 1 20 FORCED 10 CONTINUOUS 10 V 82 OUT = 3.3V MODE FIGURE 13 CIRCUIT 0 0.1 0 80 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0 5 10 15 20 25 30 35 40 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) 38582 G01 38582 G02 38582 G03
Load Step Load Step (Burst Mode Operation) (Forced Continuous Mode) Load Step (Pulse-Skipping Mode)
VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC- AC- AC- COUPLED COUPLED COUPLED IL IL 2A/DIV IL 2A/DIV 2A/DIV 20μs/DIV 38582 G04 VOUT = 3.3V 20μs/DIV 38585 G05 VOUT = 3.3V 20μs/DIV 38582 G06 VOUT = 3.3V FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT
Inductor Current at Light Load Soft-Start Tracking Start-Up
FORCED VOUT2 V CONTINUOUS 2V/DIV OUT2 2V/DIV MODE Burst Mode VOUT1 VOUT1 OPERATION 2V/DIV 2V/DIV 2A/DIV PULSE- SKIPPING MODE 2μs/DIV 38582 G07 V 38572 G09 OUT = 3.3V 20ms/DIV 38582 G08 20ms/DIV ILOAD = 200μA FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT 38582f 5
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current Efficiency vs Input Voltage
100 10000 100 98 FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT 90 V 90 IN = 12V 96 VOUT = 3.3V V V IN = 5V OUT = 3.3V I 80 1000 80 OUT = 4A 94 POWER LOSS (mW) 70 70 VIN = 12V 92 60 100 60 90 50 50 Burst Mode 88 40 OPERATION 10 40 EFFICIENCY (%) PULSE- EFFICIENCY (%) EFFICIENCY (%) 86 30 SKIPPING 30 MODE 84 20 1 20 FORCED 10 CONTINUOUS 10 V 82 OUT = 3.3V MODE FIGURE 13 CIRCUIT 0 0.1 0 80 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0 5 10 15 20 25 30 35 40 OUTPUT CURRENT (A) OUTPUT CURRENT (A) INPUT VOLTAGE (V) 38582 G01 38582 G02 38582 G03
Load Step Load Step (Burst Mode Operation) (Forced Continuous Mode) Load Step (Pulse-Skipping Mode)
VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC- AC- AC- COUPLED COUPLED COUPLED IL IL 2A/DIV IL 2A/DIV 2A/DIV 20μs/DIV 38582 G04 VOUT = 3.3V 20μs/DIV 38585 G05 VOUT = 3.3V 20μs/DIV 38582 G06 VOUT = 3.3V FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT
Inductor Current at Light Load Soft-Start Tracking Start-Up
FORCED VOUT2 V CONTINUOUS 2V/DIV OUT2 2V/DIV MODE Burst Mode VOUT1 VOUT1 OPERATION 2V/DIV 2V/DIV 2A/DIV PULSE- SKIPPING MODE 2μs/DIV 38582 G07 V 38572 G09 OUT = 3.3V 20ms/DIV 38582 G08 20ms/DIV ILOAD = 200μA FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT FIGURE 13 CIRCUIT 38582f 5
