Datasheet LTC7851, LTC7851-1 (Analog Devices) - 7
| Fabricante | Analog Devices |
| Descripción | Quad Output, Multiphase Step-Down Voltage Mode DC/DC Controller with Accurate Current Sharing |
| Páginas / Página | 38 / 7 — TYPICAL PERFORMANCE CHARACTERISTICS. Initial 7-Cycle Nonsynchronous. … |
| Revisión | A |
| Formato / tamaño de archivo | PDF / 4.2 Mb |
| Idioma del documento | Inglés |
TYPICAL PERFORMANCE CHARACTERISTICS. Initial 7-Cycle Nonsynchronous. Start-Up Response Into a 300mV
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LTC7851/LTC7851-1
TYPICAL PERFORMANCE CHARACTERISTICS Initial 7-Cycle Nonsynchronous Start-Up Response Into a 300mV Start-Up (Single Phase Using Prebiased Output (Single Phase Start-Up Into a Short (2-Phase FDMF5820DC DrMOS) Using FDMF5820DC DrMOS) Using FDMF5820DC DrMOS)
TRACK/SS IL 1V/DIV 5A/DIV IL 10A/DIV IL1 PWM 50A/DIV 5V/DIV PWM 5V/DIV IL2 V 50A/DIV OUT 500mV/DIV VIN = 12V V V V OUT OUT OUT = 1.8V 1V/DIV VIN = 12V 50mV/DIV V 10µs/DIV 7851 G14 OUT = 1.8V 200µs/DIV 7851 G16 200µs/DIV 7851 G15 VIN = 12V CTRACK/SS = 2200pF
128-Cycle Overcurrent Counter Oscillator Frequency vs RFREQ Oscillator Frequency vs RFREQ (2-Phase Using FDMF5820DC DrMOS) Frequency < 1MHz Frequency ≥ 1MHz
1050 2200 TRACK/SS1 1000 2100 2V/DIV 950 900 2000 V 850 1900 OUT 1V/DIV 800 750 1800 700 1700 IL1 650 20A/DIV 1600 600 550 1500 IL2 500 TOR FREQUENCY (kHz) 1400 TOR FREQUENCY (kHz) 20A/DIV 450 400 1300 350 1200 50µs/DIV 7851 G17 OSCILLA 300 OSCILLA 1100 VIN = 12V 250 1000 VOUT = 1.2V 200 150 900 24 27 30 33 36 39 42 45 48 51 54 45 50 55 60 65 70 75 80 85 90 RFREQ (kΩ) RFREQ (kΩ) 3681 G18 3681 G19
LTC7851-1 Overcurrent Threshold vs Temperature ILIM Pin Current vs Temperature FREQ Pin Current vs Temperature
110 20.8 20.6 100 20.6 20.4 ILIM = 860mV 90 20.4 20.2 TAGE (mV) 80 20.2 20 70 20 19.8 60 PIN CURRENT (µA) I 19.8 19.6 50 LIM = 680mV I LIM FREQ PIN CURRENT (µA) CURRENT SENSE VOL 40 19.6 19.4 30 19.4 19.2 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 7851 G20 7851 G21 7851 G22 Rev A For more information www.analog.com 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS Initial 7-Cycle Nonsynchronous Start-Up Response Into a 300mV Start-Up (Single Phase Using Prebiased Output (Single Phase Start-Up Into a Short (2-Phase FDMF5820DC DrMOS) Using FDMF5820DC DrMOS) Using FDMF5820DC DrMOS)
TRACK/SS IL 1V/DIV 5A/DIV IL 10A/DIV IL1 PWM 50A/DIV 5V/DIV PWM 5V/DIV IL2 V 50A/DIV OUT 500mV/DIV VIN = 12V V V V OUT OUT OUT = 1.8V 1V/DIV VIN = 12V 50mV/DIV V 10µs/DIV 7851 G14 OUT = 1.8V 200µs/DIV 7851 G16 200µs/DIV 7851 G15 VIN = 12V CTRACK/SS = 2200pF
128-Cycle Overcurrent Counter Oscillator Frequency vs RFREQ Oscillator Frequency vs RFREQ (2-Phase Using FDMF5820DC DrMOS) Frequency < 1MHz Frequency ≥ 1MHz
1050 2200 TRACK/SS1 1000 2100 2V/DIV 950 900 2000 V 850 1900 OUT 1V/DIV 800 750 1800 700 1700 IL1 650 20A/DIV 1600 600 550 1500 IL2 500 TOR FREQUENCY (kHz) 1400 TOR FREQUENCY (kHz) 20A/DIV 450 400 1300 350 1200 50µs/DIV 7851 G17 OSCILLA 300 OSCILLA 1100 VIN = 12V 250 1000 VOUT = 1.2V 200 150 900 24 27 30 33 36 39 42 45 48 51 54 45 50 55 60 65 70 75 80 85 90 RFREQ (kΩ) RFREQ (kΩ) 3681 G18 3681 G19
LTC7851-1 Overcurrent Threshold vs Temperature ILIM Pin Current vs Temperature FREQ Pin Current vs Temperature
110 20.8 20.6 100 20.6 20.4 ILIM = 860mV 90 20.4 20.2 TAGE (mV) 80 20.2 20 70 20 19.8 60 PIN CURRENT (µA) I 19.8 19.6 50 LIM = 680mV I LIM FREQ PIN CURRENT (µA) CURRENT SENSE VOL 40 19.6 19.4 30 19.4 19.2 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 7851 G20 7851 G21 7851 G22 Rev A For more information www.analog.com 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts