Datasheet LTC3642 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | High Efficiency, High Voltage 50mA Synchronous Step-Down Converter |
| Pages / Page | 22 / 9 — OPERATION (Refer to Block Diagram). Input Undervoltage and Overvoltage … |
| File Format / Size | PDF / 1.8 Mb |
| Document Language | English |
OPERATION (Refer to Block Diagram). Input Undervoltage and Overvoltage Lockout. Peak Inductor Current Programming
Model Line for this Datasheet
- LTC3642EDD#PBF LTC3642EDD#TRPBF LTC3642EDD-3.3#PBF LTC3642EDD-3.3#TRPBF LTC3642EDD-5#PBF LTC3642EDD-5#TRPBF LTC3642EMS8E#PBF LTC3642EMS8E#TRPBF LTC3642EMS8E-3.3#PBF LTC3642EMS8E-3.3#TRPBF LTC3642EMS8E-5#PBF LTC3642EMS8E-5#TRPBF LTC3642IDD#PBF LTC3642IDD#TRPBF LTC3642IDD-3.3#PBF LTC3642IDD-3.3#TRPBF LTC3642IDD-5#PBF LTC3642IDD-5#TRPBF LTC3642IMS8E#PBF LTC3642IMS8E#TRPBF LTC3642IMS8E-3.3#PBF LTC3642IMS8E-3.3#TRPBF LTC3642IMS8E-5#PBF LTC3642IMS8E-5#TRPBF
Text Version of Document
LTC3642
OPERATION (Refer to Block Diagram)
inductor current from 25mA during its 1ms ramp time to
Input Undervoltage and Overvoltage Lockout
the set peak current threshold. The external ramp on the The LTC3642 implements a protection feature which dis- SS pin does not limit the peak inductor current during ables switching when the input voltage is not within the start-up; however, placing a capacitor from the ISET pin 4.5V to 45V operating range. If V to ground does provide this capability. IN falls below 4V typical (4.35V maximum), an undervoltage detector disables
Peak Inductor Current Programming
switching. Similarly, if VIN rises above 50V typical (47V minimum), an overvoltage detector disables switching. The offset of the peak current comparator nominally When switching is disabled, the LTC3642 can safely sustain provides a peak inductor current of 115mA. This peak input voltages up to the absolute maximum rating of 60V. inductor current can be adjusted by placing a resistor Switching is enabled when the input voltage returns to the from the ISET pin to ground. The 1µA current sourced out 4.5V to 45V operating range. of this pin through the resistor generates a voltage that is translated into an offset in the peak current comparator, which limits the peak inductor current. 3642fc 9 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS
OPERATION (Refer to Block Diagram)
inductor current from 25mA during its 1ms ramp time to
Input Undervoltage and Overvoltage Lockout
the set peak current threshold. The external ramp on the The LTC3642 implements a protection feature which dis- SS pin does not limit the peak inductor current during ables switching when the input voltage is not within the start-up; however, placing a capacitor from the ISET pin 4.5V to 45V operating range. If V to ground does provide this capability. IN falls below 4V typical (4.35V maximum), an undervoltage detector disables
Peak Inductor Current Programming
switching. Similarly, if VIN rises above 50V typical (47V minimum), an overvoltage detector disables switching. The offset of the peak current comparator nominally When switching is disabled, the LTC3642 can safely sustain provides a peak inductor current of 115mA. This peak input voltages up to the absolute maximum rating of 60V. inductor current can be adjusted by placing a resistor Switching is enabled when the input voltage returns to the from the ISET pin to ground. The 1µA current sourced out 4.5V to 45V operating range. of this pin through the resistor generates a voltage that is translated into an offset in the peak current comparator, which limits the peak inductor current. 3642fc 9 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS
