LTC3675_15 Datasheet, PDF (14/38 Pages) Linear Technology – 7-Channel Configurable High Power PMIC

LTC3675/LTC3675-1
Pin Functions
EN1 (Pin 1): Buck Regulator 1 Enable Input. Active high.
This pin is a high impedance input; do not float.
FB1 (Pin 2): Buck Regulator 1 Feedback Pin. Receives
feedback 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 V_IN combines buck regulator 2 with
buck regulator 1 for higher current.
EN2 (Pin 4): Buck Regulator 2 Enable Input. Active high.
This pin is a high impedance input; do not float.
SW1 (Pin 5): Buck Regulator 1 Switch Node. External
inductor connects to this pin.
V_IN (Pin 6): Buck Regulator 1 Input Supply. A 10µF de-
coupling capacitor to GND is recommended. Must be con-
nected to all other V_IN supply pins (Pins 7, 10, 31, 34, 40).
V_IN (Pin 7): Buck Regulator 2 Input Supply. A 10µF de-
coupling capacitor to GND is recommended. Must be con-
nected to all other V_IN 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.
V_IN (Pin 10): Buck Regulators 3 and 4 Input Supply. A
10µF decoupling capacitor to GND is recommended. Must
be connected to all other V_IN 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.
This pin is a high impedance input; do not float.
EN4 (Pin 13): Buck Regulator 4 Enable Input. Active high.
This pin is a high impedance input; do not float.
FB4 (Pin 14): Buck Regulator 4 Feedback Pin. Receives
feedback by a resistor divider connected across the output.
Connecting FB4 to V_IN 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 V_IN 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 regulator
is more than 8% below its programmed level, this pin is
driven LOW. Assertion delay is scaled by the C_T capacitor.
IRQB (Pin 24): Interrupt Pin. Open drain output. When
undervoltage, overtemperature, or an unmasked error
condition is detected, this pin is driven LOW.
PBSTAT (Pin 25): Pushbutton Status Pin. Open drain
output. This pin provides a debounced and glitch free
status of the ONB pin.
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