LTC3675 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC3675' PDF : 36 Pages View PDF
LTC3675
PIN FUNCTIONS
EN1 (Pin 1): Buck Regulator 1 Enable Input. Active
high.
FB1 (Pin 2): Buck Regulator 1 Feedback Pin. Receives feed-
back by a resistor divider connected across the output.
FB2 (Pin 3): Buck Regulator 2 Feedback Pin. Receives
feedback by a resistor divider connected across the output.
Connecting FB2 to VIN combines buck regulator 2 with
buck regulator 1 for higher current.
EN2 (Pin 4): Buck Regulator 2 Enable Input. Active
high.
SW1 (Pin 5): Buck Regulator 1 Switch Node. External
inductor connects to this pin.
VIN (Pin 6): Buck Regulator 1 Input Supply. A 10μF decou-
pling capacitor to GND is recommended. Must be connected
to all other VIN supply pins (Pins 7, 10, 31, 34, 40).
VIN (Pin 7): Buck Regulator 2 Input Supply. A 10μF decou-
pling capacitor to GND is recommended. Must be connected
to all other VIN supply pins (Pins 6, 10, 31, 34, 40).
SW2 (Pin 8): Buck Regulator 2 Switch Node. External
inductor connects to this pin.
SW3 (Pin 9): Buck Regulator 3 Switch Node. External
inductor connects to this pin.
VIN (Pin 10): Buck Regulators 3 and 4 Input Supply. A
10μF decoupling capacitor to GND is recommended.
Must be connected to all other VIN supply pins (Pins 6,
7, 31, 34, 40).
SW4 (Pin 11): Buck Regulator 4 Switch Node. External
inductor connects to this pin.
EN3 (Pin 12): Buck Regulator 3 Enable Input. Active
high.
EN4 (Pin 13): Buck Regulator 4 Enable Input. Active
high.
FB4 (Pin 14): Buck Regulator 4 Feedback Pin. Receives
feedback by a resistor divider connected across the output.
Connecting FB4 to VIN combines buck regulator 4 with
buck regulator 3 for higher current.
FB3 (Pin 15): Buck Regulator 3 Feedback Pin. Receives
feedback by a resistor divider connected across the output.
Connecting FB3 to VIN combines buck regulator 3 with
buck regulator 2 for higher current.
LED_OV (Pin 16): Overvoltage Protection Pin for LED
Driver.
LED1 (Pin 17): Connect a string of up to 10 LEDs to this
pin.
SW7 (Pins 18, 19, 20): LED Driver Switch Node. External
inductor connects to these pins.
LED2 (Pin 21): Connect a string of up to 10 LEDs to this
pin.
CT (Pin 22): Timing Capacitor Pin. A capacitor connected
to GND sets a time constant which is scaled for use by
the WAKE, RSTB and IRQB pins.
RSTB (Pin 23): Reset Pin. Open drain output. When the
regulated output voltage of any enabled switching regula-
tor is more than 6.5% below its programmed level, this
pin is driven LOW. Assertion delay is scaled by the CT
capacitor.
IRQB (Pin 24): Interrupt Pin. Open drain output. When
undervoltage, overtemperature, or an unmasked error
condition is detected, this pin is driven LOW. Assertion
delay is scaled by the CT capacitor.
3675f
14
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