Datasheet LT8642S (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | 18V, 10A Synchronous Step-Down Silent Switcher 2 |
| Pages / Page | 26 / 7 — TYPICAL PERFORMANCE CHARACTERISTICS. RT Programmed Switching. Frequency. … |
| File Format / Size | PDF / 1.4 Mb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. RT Programmed Switching. Frequency. Minimum Input Voltage. Bias Pin Current vs VIN
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LT8642S
TYPICAL PERFORMANCE CHARACTERISTICS RT Programmed Switching Frequency Minimum Input Voltage Bias Pin Current vs VIN
250 3.2 19.0 225 3.0 18.5 200 175 2.8 18.0 150 TAGE (V) 125 2.6 17.5 100 2.4 INPUT VOL 17.0 RT PIN RESISTOR (kΩ) 75 BIAS PIN CURRENT (mA) VBIAS = 5V 50 V 2.2 OUT = 1.2V 16.5 f 25 SW = 2MHz FC MODE 0 2.0 16.0 0.2 0.6 1 1.4 1.8 2.2 2.6 3 –50 –25 0 25 50 75 100 125 4 6 8 10 12 14 16 18 SWITCHING FREQUENCY (MHz) TEMPERATURE (°C) INPUT VOLTAGE (V) 8642S G25 8642S G26 8642S G24
Bias Pin Current vs Frequency Case Temperature Rise Switching Rising Edge
30 60 VBIAS = 5V DEMO BOARD ON STILL AIR VOUT = 1.2V V 25 IN = 12V V 50 IN = 12V VBIAS = 3.3V FC MODE VOUT = 1.2V 20 40 VSW 2V/DIV 15 TURE RISE (°C) 30 10 20 BIAS PIN CURRENT (mA) 5 CASE TEMPERA 10 8642S G29 f 2ns/DIV SW = 1MHz f V SW = 2MHz IN = 12V 0 0 ILOAD = 2A 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 0 1 2 3 4 5 6 7 8 9 10 SWITCHING FREQUENCY (MHz) LOAD CURRENT (A) 8642S G27 8642S G28
Switching Waveforms, Full Switching Waveforms, CLKOUT Waveforms Frequency Continuous Operation Burst Mode Operation
V I CLKOUT L I 2V/DIV 1A/DIV L 2A/DIV VSW VSW 5V/DIV 5V/DIV VSW 5V/DIV 200ns/DIV 8642S G30 500ns/DIV 8642S G30 5µs/DIV 8642S G32 fSW = 2MHz FRONT PAGE APPLICATION FRONT PAGE APPLICATION FC MODE 12VIN TO 1.2VOUT AT 3A 12VIN TO 1.2VOUT AT 100mA VSYNC = 0V Rev 0 For more information www.analog.com 7 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 RT Programmed Switching Frequency Minimum Input Voltage Bias Pin Current vs VIN
250 3.2 19.0 225 3.0 18.5 200 175 2.8 18.0 150 TAGE (V) 125 2.6 17.5 100 2.4 INPUT VOL 17.0 RT PIN RESISTOR (kΩ) 75 BIAS PIN CURRENT (mA) VBIAS = 5V 50 V 2.2 OUT = 1.2V 16.5 f 25 SW = 2MHz FC MODE 0 2.0 16.0 0.2 0.6 1 1.4 1.8 2.2 2.6 3 –50 –25 0 25 50 75 100 125 4 6 8 10 12 14 16 18 SWITCHING FREQUENCY (MHz) TEMPERATURE (°C) INPUT VOLTAGE (V) 8642S G25 8642S G26 8642S G24
Bias Pin Current vs Frequency Case Temperature Rise Switching Rising Edge
30 60 VBIAS = 5V DEMO BOARD ON STILL AIR VOUT = 1.2V V 25 IN = 12V V 50 IN = 12V VBIAS = 3.3V FC MODE VOUT = 1.2V 20 40 VSW 2V/DIV 15 TURE RISE (°C) 30 10 20 BIAS PIN CURRENT (mA) 5 CASE TEMPERA 10 8642S G29 f 2ns/DIV SW = 1MHz f V SW = 2MHz IN = 12V 0 0 ILOAD = 2A 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 0 1 2 3 4 5 6 7 8 9 10 SWITCHING FREQUENCY (MHz) LOAD CURRENT (A) 8642S G27 8642S G28
Switching Waveforms, Full Switching Waveforms, CLKOUT Waveforms Frequency Continuous Operation Burst Mode Operation
V I CLKOUT L I 2V/DIV 1A/DIV L 2A/DIV VSW VSW 5V/DIV 5V/DIV VSW 5V/DIV 200ns/DIV 8642S G30 500ns/DIV 8642S G30 5µs/DIV 8642S G32 fSW = 2MHz FRONT PAGE APPLICATION FRONT PAGE APPLICATION FC MODE 12VIN TO 1.2VOUT AT 3A 12VIN TO 1.2VOUT AT 100mA VSYNC = 0V Rev 0 For more information www.analog.com 7 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
