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LTC3589_12 Datasheet, PDF (13/50 Pages) Linear Technology – 8-Output Regulator with Sequencing and I2C | |||
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LTC3589/LTC3589-1/
LTC3589-2
PIN FUNCTIONS
VIN_LDO2 (Pin 1): Power Input for LDO2. This pin should be
bypassed to ground with a 1μF or greater ceramic capacitor.
LDO2 (Pin 2): Output Voltage of LDO2. Nominal output
voltage is set with a resistor feedback divider that servos to
an I2C register controlled DAC reference. This pin must be
bypassed to ground with a 1μF or greater ceramic capacitor.
LDO3 (Pin 3): Output Voltage of LDO3. Nominal output
voltage is ï¬xed at 1.8V or 2.8V (LTC3589-1/LTC3589-2).
This pin must be bypassed to ground with a 1μF or greater
ceramic capacitor.
LDO4 (Pin 4): Output Voltage of LDO4. Output voltage is
selected via the I2C port. This pin must be bypassed to
ground with a 1μF or greater ceramic capacitor.
VIN_LDO34 (Pin 5): Power Input for LDO3 and LDO4. This
pin should be bypassed to ground with a 1μF or greater
ceramic capacitor.
PVIN1 (Pin 6): Power Input for Step-Down Switching
Regulator 1. Tie this pin to VIN supply. This pin should
be bypassed to ground with a 4.7μF or greater ceramic
capacitor.
SW1 (Pin 7): Switch Pin for Step-Down Switching
Regulator 1. Connect one side of step-down switching
regulator 1 inductor to this pin.
RSTO (Pin 8): Reset Output. Open-drain output pulls low
when the always-on regulator LDO1 is below regulation
and during a hard reset initiated by a pushbutton input.
EN_LDO2 (Pin 9): Enable LDO2 Logic Input. Active high
input to enable LDO2. A weak pull-down forces EN_LDO2
low when left ï¬oating.
EN1 (Pin 10): Enable Step-Down Switching Regulator 1.
Active high input to enable step-down switching
regulator 1. A weak pull-down forces EN1 low when left
ï¬oating.
EN2 (Pin 11): Enable Step-Down Switching Regulator 2.
Active high input to enable step-down switching
regulator 2. A weak pull-down forces EN2 low when left
ï¬oating.
SW4AB (Pin 12): Switch Pin for Buck-Boost Switching
Regulator 4. Connected to the buck-boost internal power
switches A and B. Connect an inductor between this pin
and SW4CD (Pin 19).
EN3 (Pin 13): Enable Step-Down Switching Regulator 3.
Active high input to enable step-down switching
regulator 3. A weak pull-down forces EN3 low when left
ï¬oating.
EN4 (Pin 14): Enable Buck-Boost Switching Regulator 4.
Active high input to enable buck-boost switching
regulator 4. A weak pull-down forces EN4 low when left
ï¬oating.
PVIN4 (Pin 15): Power Input for Switching Regulator 4.
Tie this pin to VIN supply. This pin should be bypassed to
ground with a 4.7μF or greater ceramic capacitor.
BB_OUT (Pin 16): Output Voltage of Buck-Boost Switching
Regulator 4. This pin must be bypassed to ground with a
22μF or greater ceramic capacitor.
IRQ (Pin 17): Interrupt Request Output. Open-drain
driver is pulled low for power good, undervoltage, and
overtemperature warning and fault conditions. Clear IRQ
by writing to the I2C CLIRQ command register.
EN_LDO34 (Pin 18): LTC3589 Enable LDO3 and LDO4 Logic
Input. Active high to enable LDO3 and LDO4. Disable LDO4
via I2C software commands using I2C command registers
OVEN or L2DTV2. A weak pull-down forces EN_LDO34
low when left ï¬oating.
EN_LDO3 (Pin 18): LTC3589-1/LTC3589-2 Enable LDO3
Logic Input. Active high to enable LDO3. A weak pull-down
forces EN_LDO3 low when left ï¬oating.
SW4CD (Pin 19): Switch Pin for Buck-Boost Switching
Regulator 4. Connected to the buck-boost internal power
switches C and D. Connect an inductor between this node
and SW4AB (Pin 12).
PWR_ON (Pin 20): External Power-On. Handshaking pin
to acknowledge successful power-on sequence. PWR_ON
must be driven high within ï¬ve seconds of WAKE going
high to keep power on. It can be used to activate the WAKE
output by driving high. Drive low to shut down WAKE.
3589fe
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