Datasheet LTC3877 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | Dual Phase Step-Down Synchronous Controller with VID Output Voltage Programming and Low Value DCR Sensing |
| Pages / Page | 46 / 6 — Typical perForMance characTerisTics. Efficiency. vs Output Current and … |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
Typical perForMance characTerisTics. Efficiency. vs Output Current and Mode. (Circuit on Last Page)
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LTC3877
Typical perForMance characTerisTics Efficiency Efficiency vs Output Current and Mode vs Output Current and Mode Efficiency (Circuit on Last Page) (Circuit on Last Page) vs Output Current and Voltage
100 100 95 90 90 90 80 VIN = 12V 80 V V IN = 12V OUT = 1.2V 85 V VIN = 12V 70 70 OUT = 0.9V 80 CCM 60 60 75 50 50 70 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 30 65 20 20 60 VOUT = 0.9V 10 BURST MODE 10 BURST MODE 55 VOUT = 1.2V CONTINUOUS MODE CONTINUOUS MODE V 0 0 OUT = 1.8V 50 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 3877 G01 3877 G02 3877 G03
Load Step Load Step Load Step (Figure 16 Application Circuit) (Figure 16 Application Circuit) (Figure 16 Application Circuit) (Burst Mode Operation) (Forced Continuous Mode) (Pulse-Skipping Mode)
ILOAD ILOAD ILOAD 40A/DIV 40A/DIV 40A/DIV 5A TO 40A 5A TO 40A 5A TO 40A IL1, IL2 IL1, IL2 IL1, IL2 10A/DIV 10A/DIV 10A/DIV VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC-COUPLED AC-COUPLED AC-COUPLED 50µs/DIV 3877 G04 VIN = 12V 50µs/DIV 3877 G05 VIN = 12V 50µs/DIV 3877 G06 VIN = 12V VOUT = 0.9V VOUT = 0.9V VOUT = 0.9V
Inductor Current at Light Load Prebiased Output at 0.6V Coincident Tracking
FORCED CONTINUOUS MODE VOUT RUN 10A/DIV 500mV/DIV 2V/DIV Burst Mode VOUT1 OPERATION 10A/DIV VFB VOUT2 PULSE- 500mV/DIV SKIPPING TK/SS VOUT1 MODE 500mV/DIV VOUT2 10A/DIV 500mV/DIV VIN = 12V 5µs/DIV 3877 G07 2.0ms/DIV 3877 G08 VIN = 12V 20ms/DIV 3877 G09 VIN = 12V VOUT = 0.9V VOUT = 0.9V VOUT1 = 1.2V, RLOAD = 12Ω, CCM ILOAD = 2A CCM: NO LOAD VOUT2 = 0.9V, RLOAD = 6Ω, CCM 3877f 6 For more information www.linear.com/LTC3877
Typical perForMance characTerisTics Efficiency Efficiency vs Output Current and Mode vs Output Current and Mode Efficiency (Circuit on Last Page) (Circuit on Last Page) vs Output Current and Voltage
100 100 95 90 90 90 80 VIN = 12V 80 V V IN = 12V OUT = 1.2V 85 V VIN = 12V 70 70 OUT = 0.9V 80 CCM 60 60 75 50 50 70 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 30 65 20 20 60 VOUT = 0.9V 10 BURST MODE 10 BURST MODE 55 VOUT = 1.2V CONTINUOUS MODE CONTINUOUS MODE V 0 0 OUT = 1.8V 50 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 3877 G01 3877 G02 3877 G03
Load Step Load Step Load Step (Figure 16 Application Circuit) (Figure 16 Application Circuit) (Figure 16 Application Circuit) (Burst Mode Operation) (Forced Continuous Mode) (Pulse-Skipping Mode)
ILOAD ILOAD ILOAD 40A/DIV 40A/DIV 40A/DIV 5A TO 40A 5A TO 40A 5A TO 40A IL1, IL2 IL1, IL2 IL1, IL2 10A/DIV 10A/DIV 10A/DIV VOUT VOUT VOUT 100mV/DIV 100mV/DIV 100mV/DIV AC-COUPLED AC-COUPLED AC-COUPLED 50µs/DIV 3877 G04 VIN = 12V 50µs/DIV 3877 G05 VIN = 12V 50µs/DIV 3877 G06 VIN = 12V VOUT = 0.9V VOUT = 0.9V VOUT = 0.9V
Inductor Current at Light Load Prebiased Output at 0.6V Coincident Tracking
FORCED CONTINUOUS MODE VOUT RUN 10A/DIV 500mV/DIV 2V/DIV Burst Mode VOUT1 OPERATION 10A/DIV VFB VOUT2 PULSE- 500mV/DIV SKIPPING TK/SS VOUT1 MODE 500mV/DIV VOUT2 10A/DIV 500mV/DIV VIN = 12V 5µs/DIV 3877 G07 2.0ms/DIV 3877 G08 VIN = 12V 20ms/DIV 3877 G09 VIN = 12V VOUT = 0.9V VOUT = 0.9V VOUT1 = 1.2V, RLOAD = 12Ω, CCM ILOAD = 2A CCM: NO LOAD VOUT2 = 0.9V, RLOAD = 6Ω, CCM 3877f 6 For more information www.linear.com/LTC3877
