Datasheet LTC3631 (Analog Devices) - 9
| Hersteller | Analog Devices |
| Beschreibung | High Efficiency, High Voltage 100mA Synchronous Step-Down Converter |
| Seiten / Seite | 22 / 9 — operaTion (Refer to Block Diagram). Input Undervoltage and Overvoltage … |
| Dateiformat / Größe | PDF / 538 Kb |
| Dokumentensprache | Englisch |
operaTion (Refer to Block Diagram). Input Undervoltage and Overvoltage Lockout. Peak Inductor Current Programming
Modelllinie für dieses Datenblatt
- LTC3631EDD#PBF LTC3631EDD#TRPBF LTC3631EDD-3.3#PBF LTC3631EDD-3.3#TRPBF LTC3631EDD-5#PBF LTC3631EDD-5#TRPBF LTC3631EMS8E#PBF LTC3631EMS8E#TRPBF LTC3631EMS8E-3.3#PBF LTC3631EMS8E-3.3#TRPBF LTC3631EMS8E-5#PBF LTC3631EMS8E-5#TRPBF LTC3631IDD#PBF LTC3631IDD#TRPBF LTC3631IDD-3.3#PBF LTC3631IDD-3.3#TRPBF LTC3631IDD-5#PBF LTC3631IDD-5#TRPBF LTC3631IMS8E#PBF LTC3631IMS8E#TRPBF LTC3631IMS8E-3.3#PBF LTC3631IMS8E-3.3#TRPBF LTC3631IMS8E-5#PBF LTC3631IMS8E-5#TRPBF
Textversion des Dokuments
LTC3631
operaTion (Refer to Block Diagram)
then the output voltage will be limited by the ramp rate from the ISET pin to ground. The 1µA current sourced out on the SS pin instead. The internal and external soft-start of this pin through the resistor generates a voltage that is functions are reset on start-up and after an undervoltage translated into an offset in the peak current comparator, or overvoltage event on the input supply. which limits the peak inductor current. In order to ensure a smooth start-up transition in any
Input Undervoltage and Overvoltage Lockout
application, the internal soft-start also ramps the peak inductor current from 50mA during its 1ms ramp time to The LTC3631 implements a protection feature which dis- the set peak current threshold. The external ramp on the ables switching when the input voltage is not within the SS pin does not limit the peak inductor current during 4.5V to 45V operating range. If VIN falls below 4V typical start-up; however, placing a capacitor from the ISET pin (4.35V maximum), an undervoltage detector disables to ground does provide this capability. switching. Similarly, if VIN rises above 50V typical (47V minimum), an overvoltage detector disables switching.
Peak Inductor Current Programming
When switching is disabled, the LTC3631 can safely sustain The offset of the peak current comparator nominally input voltages up to the absolute maximum rating of 60V. provides a peak inductor current of 225mA. This peak Switching is enabled when the input voltage returns to the inductor current can be adjusted by placing a resistor 4.5V to 45V operating range. 3631fe For more information www.linear.com/LTC3631 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts
operaTion (Refer to Block Diagram)
then the output voltage will be limited by the ramp rate from the ISET pin to ground. The 1µA current sourced out on the SS pin instead. The internal and external soft-start of this pin through the resistor generates a voltage that is functions are reset on start-up and after an undervoltage translated into an offset in the peak current comparator, or overvoltage event on the input supply. which limits the peak inductor current. In order to ensure a smooth start-up transition in any
Input Undervoltage and Overvoltage Lockout
application, the internal soft-start also ramps the peak inductor current from 50mA during its 1ms ramp time to The LTC3631 implements a protection feature which dis- the set peak current threshold. The external ramp on the ables switching when the input voltage is not within the SS pin does not limit the peak inductor current during 4.5V to 45V operating range. If VIN falls below 4V typical start-up; however, placing a capacitor from the ISET pin (4.35V maximum), an undervoltage detector disables to ground does provide this capability. switching. Similarly, if VIN rises above 50V typical (47V minimum), an overvoltage detector disables switching.
Peak Inductor Current Programming
When switching is disabled, the LTC3631 can safely sustain The offset of the peak current comparator nominally input voltages up to the absolute maximum rating of 60V. provides a peak inductor current of 225mA. This peak Switching is enabled when the input voltage returns to the inductor current can be adjusted by placing a resistor 4.5V to 45V operating range. 3631fe For more information www.linear.com/LTC3631 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts