Datasheet LT8640S, LT8643S (Analog Devices) - 7
| Fabricante | Analog Devices |
| Descripción | 42V, 6A Synchronous Step-Down Silent Switcher 2 with 2.5µA Quiescent Current |
| Páginas / Página | 30 / 7 — Typical perForMance characTerisTics. Top FET Current Limit vs Duty Cycle. … |
| Formato / tamaño de archivo | PDF / 2.3 Mb |
| Idioma del documento | Inglés |
Typical perForMance characTerisTics. Top FET Current Limit vs Duty Cycle. Top FET Current Limit. Switch Drop vs Temperature
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LT8640S/LT8643S
Typical perForMance characTerisTics Top FET Current Limit vs Duty Cycle Top FET Current Limit Switch Drop vs Temperature
11.0 12 150 SWITCH CURRENT = 1A 10.5 125 10.0 11 9.5 100 9.0 TOP SWITCH 8.5 10 5% DC 75 8.0 CURRENT LIMIT (A) 50 7.5 CURRENT LIMIT (A) SWITCH DROP (mV) 9 7.0 25 BOTTOM SWITCH 6.5 6.0 8 0 0.1 0.3 0.5 0.7 0.9 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 DUTY CYCLE TEMPERATURE (°C) TEMPERATURE (°C) 8640S G19 8640S G20 8640S G21
Switch Drop vs Switch Current Dropout Voltage Minimum On-Time
500 600 44 VIN = 5V Burst Mode OPERATION 450 VOUT SET TO REGULATE AT 5V FORCED CONTINUOUS MODE 400 500 L = IHLP3232DZ-01, 1µH 40 350 400 36 300 TAGE (mV) 250 300 32 TOP SWITCH 200 SWITCH DROP (mV) 150 200 28 DROPOUT VOL MINIMUM ON–TIME (ns) 100 100 ILOAD = 2A 24 50 VOUT = 0.97V BOTTOM SWITCH fSW = 3MHz 0 0 20 0 1 2 3 4 5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 –50 –25 0 25 50 75 100 125 SWITCH CURRENT (A) LOAD CURRENT (A) TEMPERATURE (°C) 8640S G22 8640S G23 8640S G24
Switching Frequency Burst Frequency LT8640S Soft-Start Tracking
740 1200 1.2 RT = 60.4k 730 1000 1.0 720 800 0.8 710 700 600 0.6 690 400 FB VOLTAGE (V) 0.4 680 SWITCHING FREQUENCY (kHz) SWITCHING FREQUENCY (kHz) FRONT PAGE APPLICATION 200 0.2 670 VIN = 12V VOUT = 5V 660 0 0 –50 –25 0 25 50 75 100 125 0 100 200 300 400 500 600 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 TEMPERATURE (°C) LOAD CURRENT (mA) TR/SS VOLTAGE (V) 8640S G25 8640S G26 8640S G27 8640sfa For more information www.linear.com/LT8640S 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts
Typical perForMance characTerisTics Top FET Current Limit vs Duty Cycle Top FET Current Limit Switch Drop vs Temperature
11.0 12 150 SWITCH CURRENT = 1A 10.5 125 10.0 11 9.5 100 9.0 TOP SWITCH 8.5 10 5% DC 75 8.0 CURRENT LIMIT (A) 50 7.5 CURRENT LIMIT (A) SWITCH DROP (mV) 9 7.0 25 BOTTOM SWITCH 6.5 6.0 8 0 0.1 0.3 0.5 0.7 0.9 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 DUTY CYCLE TEMPERATURE (°C) TEMPERATURE (°C) 8640S G19 8640S G20 8640S G21
Switch Drop vs Switch Current Dropout Voltage Minimum On-Time
500 600 44 VIN = 5V Burst Mode OPERATION 450 VOUT SET TO REGULATE AT 5V FORCED CONTINUOUS MODE 400 500 L = IHLP3232DZ-01, 1µH 40 350 400 36 300 TAGE (mV) 250 300 32 TOP SWITCH 200 SWITCH DROP (mV) 150 200 28 DROPOUT VOL MINIMUM ON–TIME (ns) 100 100 ILOAD = 2A 24 50 VOUT = 0.97V BOTTOM SWITCH fSW = 3MHz 0 0 20 0 1 2 3 4 5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 –50 –25 0 25 50 75 100 125 SWITCH CURRENT (A) LOAD CURRENT (A) TEMPERATURE (°C) 8640S G22 8640S G23 8640S G24
Switching Frequency Burst Frequency LT8640S Soft-Start Tracking
740 1200 1.2 RT = 60.4k 730 1000 1.0 720 800 0.8 710 700 600 0.6 690 400 FB VOLTAGE (V) 0.4 680 SWITCHING FREQUENCY (kHz) SWITCHING FREQUENCY (kHz) FRONT PAGE APPLICATION 200 0.2 670 VIN = 12V VOUT = 5V 660 0 0 –50 –25 0 25 50 75 100 125 0 100 200 300 400 500 600 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 TEMPERATURE (°C) LOAD CURRENT (mA) TR/SS VOLTAGE (V) 8640S G25 8640S G26 8640S G27 8640sfa For more information www.linear.com/LT8640S 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts