Datasheet LT8641 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 65V, 3.5A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current |
| Pages / Page | 26 / 6 — TYPICAL PERFORMANCE CHARACTERISTICS. Dropout Voltage. Switching … |
| Revision | C |
| File Format / Size | PDF / 3.4 Mb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Dropout Voltage. Switching Frequency. Burst Frequency. Minimum Load to Full Frequency
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LT8641
TYPICAL PERFORMANCE CHARACTERISTICS Dropout Voltage Switching Frequency Burst Frequency
600 740 1200 VIN = 5V RT = 60.4k FRONT PAGE APPLICATION VOUT SET TO REGULATE AT 5V 730 500 VIN = 12V L = WE–LHMI7050, 1µH 1000 VOUT = 5V 720 400 800 710 TAGE (mV) 300 700 600 690 200 400 DROPOUT VOL 680 100 SWITCHING FREQUENCY (kHz) SWITCHING FREQUENCY (kHz) 200 670 0 660 0 0 0.5 1 1.5 2 2.5 3 3.5 –50 –25 0 25 50 75 100 125 150 0 200 400 600 800 LOAD CURRENT (A) TEMPERATURE (°C) LOAD CURRENT (mA) 8641 G19 8641 G20 8641 G21
Minimum Load to Full Frequency (Pulse-Skipping Mode) Frequency Foldback Soft-Start Tracking
140 800 1.0 V FRONT PAGE APPLICATION OUT = 3.3V V 120 OUT = 5V 700 VIN = 12V V f SYNC = 0V SW = 1MHz 0.8 600 RT = 60.4k 100 500 80 0.6 400 TAGE (V) 60 300 0.4 FB VOL LOAD CURRENT (mA) 40 200 SWITCHING FREQUENCY (kHz) 0.2 20 100 0 0 0 5 15 25 35 45 55 65 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1.0 1.2 INPUT VOLTAGE (V) FB VOLTAGE (V) TR/SS VOLTAGE (V) 8641 G22 8641 G24 8641 G23
Soft-Start Current Soft–Start Current PG High Thresholds PG Low Thresholds
2.2 10.0 –6.0 VSS = 0.5V 2.1 9.5 (%) –6.5 (%) REF REF 2.0 9.0 –7.0 1.9 8.5 –7.5 FB RISING FB RISING 1.8 8.0 –8.0 1.7 7.5 –8.5 FB FALLING SS PIN CURRENT (µA) FB FALLING 1.6 7.0 –9.0 1.5 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V 1.4 6.0 –10.0 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 8641 G25 8641 G26 8641 G27 Rev. C 6 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Applications Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS Dropout Voltage Switching Frequency Burst Frequency
600 740 1200 VIN = 5V RT = 60.4k FRONT PAGE APPLICATION VOUT SET TO REGULATE AT 5V 730 500 VIN = 12V L = WE–LHMI7050, 1µH 1000 VOUT = 5V 720 400 800 710 TAGE (mV) 300 700 600 690 200 400 DROPOUT VOL 680 100 SWITCHING FREQUENCY (kHz) SWITCHING FREQUENCY (kHz) 200 670 0 660 0 0 0.5 1 1.5 2 2.5 3 3.5 –50 –25 0 25 50 75 100 125 150 0 200 400 600 800 LOAD CURRENT (A) TEMPERATURE (°C) LOAD CURRENT (mA) 8641 G19 8641 G20 8641 G21
Minimum Load to Full Frequency (Pulse-Skipping Mode) Frequency Foldback Soft-Start Tracking
140 800 1.0 V FRONT PAGE APPLICATION OUT = 3.3V V 120 OUT = 5V 700 VIN = 12V V f SYNC = 0V SW = 1MHz 0.8 600 RT = 60.4k 100 500 80 0.6 400 TAGE (V) 60 300 0.4 FB VOL LOAD CURRENT (mA) 40 200 SWITCHING FREQUENCY (kHz) 0.2 20 100 0 0 0 5 15 25 35 45 55 65 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1.0 1.2 INPUT VOLTAGE (V) FB VOLTAGE (V) TR/SS VOLTAGE (V) 8641 G22 8641 G24 8641 G23
Soft-Start Current Soft–Start Current PG High Thresholds PG Low Thresholds
2.2 10.0 –6.0 VSS = 0.5V 2.1 9.5 (%) –6.5 (%) REF REF 2.0 9.0 –7.0 1.9 8.5 –7.5 FB RISING FB RISING 1.8 8.0 –8.0 1.7 7.5 –8.5 FB FALLING SS PIN CURRENT (µA) FB FALLING 1.6 7.0 –9.0 1.5 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V 1.4 6.0 –10.0 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 8641 G25 8641 G26 8641 G27 Rev. C 6 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Applications Related Parts
