Datasheet

LTC3675/LTC3675-1
2
36751fc
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Table oF conTenTs
Features ............................................................................................................................ 1
Applications ....................................................................................................................... 1
Typical Application ............................................................................................................... 1
Description......................................................................................................................... 1
Absolute Maximum Ratings ..................................................................................................... 3
Order Information ................................................................................................................. 3
Pin Configuration ................................................................................................................. 3
Electrical Characteristics ........................................................................................................ 4
Typical Performance Characteristics .......................................................................................... 8
Pin Functions .....................................................................................................................14
Block Diagram ....................................................................................................................16
Operation..........................................................................................................................17
Buck Switching Regulator .................................................................................................................................... 17
Buck Regulators with Combined Power Stages .................................................................................................... 17
Boost Switching Regulator ................................................................................................................................... 18
Buck-Boost Switching Regulator .......................................................................................................................... 18
LED Driver ............................................................................................................................................................ 18
Pushbutton Interface and Power-Up Power-Down Sequencing ............................................................................ 19
Power-Up and Power-Down via Pushbutton ......................................................................................................... 19
Power-Up and Power-Down via Enable Pin or I
2
C ................................................................................................. 21
LED Current Programming ................................................................................................................................... 21
I
2
C Interface .......................................................................................................................................................... 21
Error Condition Reporting via
RSTB and IRQB Pins ............................................................................................................................................. 24
Undervoltage and Overtemperature Functionality ................................................................................................. 25
Applications Information .......................................................................................................26
Switching Regulator Output Voltage and Feedback Network................................................................................. 26
Buck Regulators ................................................................................................................................................... 26
Combined Buck Regulators .................................................................................................................................. 26
Boost Regulator .................................................................................................................................................... 27
Buck-Boost Regulator ........................................................................................................................................... 28
LED Driver ............................................................................................................................................................ 28
Operating the LED Driver As a High Voltage Boost Regulator ............................................................................... 29
Input and Output Decoupling Capacitor Selection ................................................................................................. 29
Choosing the C
T
Capacitor ................................................................................................................................... 30
Programming the UVOT Register ......................................................................................................................... 30
Programming the RSTB and IRQB Mask Registers .............................................................................................. 30
Status Byte Read Back ......................................................................................................................................... 31
PCB Considerations .............................................................................................................................................. 31
Typical Applications .............................................................................................................33
Package Description ............................................................................................................36
Revision History .................................................................................................................37
Typical Application ..............................................................................................................38
Related Parts .....................................................................................................................38