Datasheet LTC3878 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | Fast, Wide Operating Range No RSENSE Step-Down DC/DC Controller |
| Pages / Page | 26 / 4 — Transient Response FCM. (Forced Continuous Mode). Positive Load Step. … |
| File Format / Size | PDF / 413 Kb |
| Document Language | English |
Transient Response FCM. (Forced Continuous Mode). Positive Load Step. Negative Load Step. Transient Response DCM
Model Line for this Datasheet
Text Version of Document
LTC3878 Typical perForMance characTerisTics
Transient Response FCM Transient Response FCM Transient Response FCM (Forced Continuous Mode) Positive Load Step Negative Load Step
VSW VSW 20V/DIV 20V/DIV VOUT (AC) 50mV/DIV V V OUT (AC) OUT (AC) 50mV/DIV 50mV/DIV IL I 10A/DIV IL L 10A/DIV 10A/DIV ILOAD ILOAD ILOAD 10A/DIV 10A/DIV 10A/DIV 50µs/DIV 3878 G01 5µs/DIV 3878 G02 5µs/DIV 3878 G03 LOAD STEP 0A TO 10A TO 0A LOAD STEP 0A TO 10A LOAD STEP 10A TO 0A VIN = 12V VIN = 12V VIN = 12V VOUT = 1.2V VOUT = 1.2V VOUT = 1.2V FCB = 0V FCB = 0V FCB = 0V SW FREQ = 400kHz SW FREQ = 400kHz SW FREQ = 400kHz FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT
Transient Response DCM Normal Start-Up, RUN/SS (Discontinuous Mode) Release from Zero Start-Up VIN Cycled Low and High
VIN RUN/SS 10V/DIV VOUT (AC) 2V/DIV 50mV/DIV RUN/SS 5V/DIV IL IL IL 10A/DIV 10A/DIV 10A/DIV I V LOAD OUT VOUT 10A/DIV 500mV/DIV 1V/DIV 50µs/DIV 3878 G04 V 50ms/DIV 3878 G05 3878 G06 IN = 12V V 100ms/DIV IN = 12V LOAD STEP 1A TO 11A TO 1A VOUT = 1.2V VOUT = 1.2V VIN = 12V FCB = 0V FCB = 0V VOUT = 1.2V SW FREQ = 400kHz SW FREQ = 400kHz FCB = INTVCC FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT SW FREQ = 400kHz FIGURE 7 CIRCUIT
Efficiency vs Load Current Efficiency vs Input Voltage Frequency vs Input Voltage
100 100 420 90 DISCONTINUOUS 95 410 15A MODE 400 80 90 15A CCM 390 70 85 380 60 CONTINUOUS 80 MODE 1A DCM 370 50 75 360 0A 40 70 350 EFFICIENCY (%) EFFICIENCY (%) 1A CCM 340 30 65 FREQUENCY (kHz) 330 20 VIN = 12V 60 V V OUT = 1.2V OUT = 1.2V 320 10 SW FREQ = 400kHz 55 SW FREQ = 400kHz VOUT = 1.2V FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT 310 FIGURE 7 CIRCUIT 0 50 300 0.01 0.1 1 10 100 4 8 12 16 20 24 28 4 8 12 16 20 24 28 LOAD CURRENT (A) VIN (V) VIN (V) 3878 G07 3878 G08 3878 G09 3878fa 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 Typical Application Related Parts
Transient Response FCM Transient Response FCM Transient Response FCM (Forced Continuous Mode) Positive Load Step Negative Load Step
VSW VSW 20V/DIV 20V/DIV VOUT (AC) 50mV/DIV V V OUT (AC) OUT (AC) 50mV/DIV 50mV/DIV IL I 10A/DIV IL L 10A/DIV 10A/DIV ILOAD ILOAD ILOAD 10A/DIV 10A/DIV 10A/DIV 50µs/DIV 3878 G01 5µs/DIV 3878 G02 5µs/DIV 3878 G03 LOAD STEP 0A TO 10A TO 0A LOAD STEP 0A TO 10A LOAD STEP 10A TO 0A VIN = 12V VIN = 12V VIN = 12V VOUT = 1.2V VOUT = 1.2V VOUT = 1.2V FCB = 0V FCB = 0V FCB = 0V SW FREQ = 400kHz SW FREQ = 400kHz SW FREQ = 400kHz FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT
Transient Response DCM Normal Start-Up, RUN/SS (Discontinuous Mode) Release from Zero Start-Up VIN Cycled Low and High
VIN RUN/SS 10V/DIV VOUT (AC) 2V/DIV 50mV/DIV RUN/SS 5V/DIV IL IL IL 10A/DIV 10A/DIV 10A/DIV I V LOAD OUT VOUT 10A/DIV 500mV/DIV 1V/DIV 50µs/DIV 3878 G04 V 50ms/DIV 3878 G05 3878 G06 IN = 12V V 100ms/DIV IN = 12V LOAD STEP 1A TO 11A TO 1A VOUT = 1.2V VOUT = 1.2V VIN = 12V FCB = 0V FCB = 0V VOUT = 1.2V SW FREQ = 400kHz SW FREQ = 400kHz FCB = INTVCC FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT SW FREQ = 400kHz FIGURE 7 CIRCUIT
Efficiency vs Load Current Efficiency vs Input Voltage Frequency vs Input Voltage
100 100 420 90 DISCONTINUOUS 95 410 15A MODE 400 80 90 15A CCM 390 70 85 380 60 CONTINUOUS 80 MODE 1A DCM 370 50 75 360 0A 40 70 350 EFFICIENCY (%) EFFICIENCY (%) 1A CCM 340 30 65 FREQUENCY (kHz) 330 20 VIN = 12V 60 V V OUT = 1.2V OUT = 1.2V 320 10 SW FREQ = 400kHz 55 SW FREQ = 400kHz VOUT = 1.2V FIGURE 7 CIRCUIT FIGURE 7 CIRCUIT 310 FIGURE 7 CIRCUIT 0 50 300 0.01 0.1 1 10 100 4 8 12 16 20 24 28 4 8 12 16 20 24 28 LOAD CURRENT (A) VIN (V) VIN (V) 3878 G07 3878 G08 3878 G09 3878fa 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 Typical Application Related Parts
