Datasheet LT8648S (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | 42V, 15A Synchronous Step-Down Silent Switcher 2 |
| Pages / Page | 28 / 7 — TYPICAL PERFORMANCE CHARACTERISTICS. Burst Frequency. Soft-Start … |
| File Format / Size | PDF / 2.2 Mb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS. Burst Frequency. Soft-Start Tracking. Soft–Start T. Soft-Start Current
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LT8648S
TYPICAL PERFORMANCE CHARACTERISTICS Burst Frequency Soft-Start Tracking Soft–Start T Soft-Start Current
1200 0.8 2.4 VSS = 0.5V 2.3 1000 0.6 2.2 800 2.1 600 TAGE (V) 0.4 2.0 1.9 400 FB VOL SS PIN CURRENT (µA) 0.2 1.8 SWITCHING FREQUENCY (kHz) FRONT PAGE APPLICATION 200 VIN = 12V 1.7 VOUT = 5V 0 0 1.6 0 0.4 0.8 1.2 1.6 2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 –50 –25 0 25 50 75 100 125 150 LOAD CURRENT (A) SS VOLTAGE (V) TEMPERATURE (°C) 8648S G19 8648S G20 8648S G21
Error Amp Output Current PG High Thresholds PG Low Thresholds
400 10.0 –6.0 300 9.5 (%) –6.5 (%) REF REF 200 9.0 –7.0 FB RISING 100 8.5 –7.5 0 8.0 FB RISING –8.0 FB FALLING –100 7.5 –8.5 PIN CURRENT (µA) FB FALLING V C –200 7.0 –9.0 –300 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V VC = 1.25V –400 6.0 –10.0 –200 –100 0 100 200 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 FB PIN ERROR VOLTAGE (mV) TEMPERATURE (°C) TEMPERATURE (°C) 8648S G22 8648S G23 8648S G24
RT Programmed Switching RT Programmed Switching Frequency Minimum Input Voltage Minimum Input V Bias Pin Current vs Input Voltage Bias Pin Current vs Input V
250 3.2 50 225 45 200 3.0 175 fSW = 2MHz 2.8 40 150 TAGE (V) 125 2.6 35 100 30 75 2.4 INPUT VOL RT PIN RESISTOR (kΩ) fSW = 400kHz BIAS PIN CURRENT (mA) VBIAS = 5V 50 V 2.2 OUT = 5V 25 f 25 SW = 1MHz FC MODE 0 2.0 20 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 –50 –25 0 25 50 75 100 125 150 5 10 15 20 25 30 35 40 SWITCHING FREQUENCY (MHz) TEMPERATURE (°C) INPUT VOLTAGE (V) 8648S G25 8648S G26 8648S G27 Rev. 0 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 Applications Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS Burst Frequency Soft-Start Tracking Soft–Start T Soft-Start Current
1200 0.8 2.4 VSS = 0.5V 2.3 1000 0.6 2.2 800 2.1 600 TAGE (V) 0.4 2.0 1.9 400 FB VOL SS PIN CURRENT (µA) 0.2 1.8 SWITCHING FREQUENCY (kHz) FRONT PAGE APPLICATION 200 VIN = 12V 1.7 VOUT = 5V 0 0 1.6 0 0.4 0.8 1.2 1.6 2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 –50 –25 0 25 50 75 100 125 150 LOAD CURRENT (A) SS VOLTAGE (V) TEMPERATURE (°C) 8648S G19 8648S G20 8648S G21
Error Amp Output Current PG High Thresholds PG Low Thresholds
400 10.0 –6.0 300 9.5 (%) –6.5 (%) REF REF 200 9.0 –7.0 FB RISING 100 8.5 –7.5 0 8.0 FB RISING –8.0 FB FALLING –100 7.5 –8.5 PIN CURRENT (µA) FB FALLING V C –200 7.0 –9.0 –300 6.5 –9.5 PG THRESHOLD OFFSET FROM V PG THRESHOLD OFFSET FROM V VC = 1.25V –400 6.0 –10.0 –200 –100 0 100 200 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 FB PIN ERROR VOLTAGE (mV) TEMPERATURE (°C) TEMPERATURE (°C) 8648S G22 8648S G23 8648S G24
RT Programmed Switching RT Programmed Switching Frequency Minimum Input Voltage Minimum Input V Bias Pin Current vs Input Voltage Bias Pin Current vs Input V
250 3.2 50 225 45 200 3.0 175 fSW = 2MHz 2.8 40 150 TAGE (V) 125 2.6 35 100 30 75 2.4 INPUT VOL RT PIN RESISTOR (kΩ) fSW = 400kHz BIAS PIN CURRENT (mA) VBIAS = 5V 50 V 2.2 OUT = 5V 25 f 25 SW = 1MHz FC MODE 0 2.0 20 0.2 0.6 1 1.4 1.8 2.2 2.6 3.0 –50 –25 0 25 50 75 100 125 150 5 10 15 20 25 30 35 40 SWITCHING FREQUENCY (MHz) TEMPERATURE (°C) INPUT VOLTAGE (V) 8648S G25 8648S G26 8648S G27 Rev. 0 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 Applications Related Parts
