Datasheet LT8642S (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 18V, 10A Synchronous Step-Down Silent Switcher 2 |
| Pages / Page | 26 / 6 — TYPICAL PERFORMANCE CHARACTERISTICS. Minimum On-Time. Switching … |
| File Format / Size | PDF / 1.4 Mb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Minimum On-Time. Switching Frequency. Burst Frequency. Soft-Start Tracking
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LT8642S
TYPICAL PERFORMANCE CHARACTERISTICS Minimum On-Time Switching Frequency Burst Frequency
40 2.025 2.5 ILOAD = 3A RT = 18.2k FRONT PAGE APPLICATION VOUT = 0.6V VIN = 12V 35 f 2.000 SW = 3MHz VOUT = 1.2V 2.0 30 1.975 1.5 25 1.950 1.0 20 1.925 MINIMUM ON–TIME (ns) 0.5 15 SWITCHING FREQUENCY (MHz) 1.900 SWITCHING FREQUENCY (MHz) Burst Mode OPERATION FORCED CONTINUOUS MODE 10 1.875 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 0.25 0.50 0.75 1 1.25 1.50 1.75 2 TEMPERATURE (°C) TEMPERATURE (°C) LOAD CURRENT (A) 8642S G16 8642S G17 8642S G18
Soft-Start Tracking Soft-Start Current Error Amp Output Current
0.8 2.4 500 VSS = 0.5V 2.3 375 0.6 2.2 250 2.1 125 TAGE (V) 0.4 2.0 0 1.9 FB VOL –125 PIN CURRENT (µA) SS PIN CURRENT (µA) 0.2 1.8 V C –250 1.7 –375 VC = 1.25V 0 1.6 –500 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 –50 –25 0 25 50 75 100 125 –200 –100 0 100 200 SS VOLTAGE (V) TEMPERATURE (°C) FB PIN ERROR VOLTAGE (mV) 8642S G19 8642S G20 8642S G21
PG High Thresholds PG Low Thresholds
10.0 –6.0 9.5 –6.5 (%) (%) REF REF 9.0 –7.0 8.5 –7.5 FB RISING FB RISING 8.0 –8.0 7.5 –8.5 FB FALLING FB FALLING 7.0 –9.0 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V 6.0 –10.0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) 8642S G22 8642S G23 Rev 0 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 Package Description Typical Applications Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS Minimum On-Time Switching Frequency Burst Frequency
40 2.025 2.5 ILOAD = 3A RT = 18.2k FRONT PAGE APPLICATION VOUT = 0.6V VIN = 12V 35 f 2.000 SW = 3MHz VOUT = 1.2V 2.0 30 1.975 1.5 25 1.950 1.0 20 1.925 MINIMUM ON–TIME (ns) 0.5 15 SWITCHING FREQUENCY (MHz) 1.900 SWITCHING FREQUENCY (MHz) Burst Mode OPERATION FORCED CONTINUOUS MODE 10 1.875 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 0.25 0.50 0.75 1 1.25 1.50 1.75 2 TEMPERATURE (°C) TEMPERATURE (°C) LOAD CURRENT (A) 8642S G16 8642S G17 8642S G18
Soft-Start Tracking Soft-Start Current Error Amp Output Current
0.8 2.4 500 VSS = 0.5V 2.3 375 0.6 2.2 250 2.1 125 TAGE (V) 0.4 2.0 0 1.9 FB VOL –125 PIN CURRENT (µA) SS PIN CURRENT (µA) 0.2 1.8 V C –250 1.7 –375 VC = 1.25V 0 1.6 –500 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 –50 –25 0 25 50 75 100 125 –200 –100 0 100 200 SS VOLTAGE (V) TEMPERATURE (°C) FB PIN ERROR VOLTAGE (mV) 8642S G19 8642S G20 8642S G21
PG High Thresholds PG Low Thresholds
10.0 –6.0 9.5 –6.5 (%) (%) REF REF 9.0 –7.0 8.5 –7.5 FB RISING FB RISING 8.0 –8.0 7.5 –8.5 FB FALLING FB FALLING 7.0 –9.0 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V 6.0 –10.0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) 8642S G22 8642S G23 Rev 0 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 Package Description Typical Applications Related Parts
