LTC3589 Linear Technology, LTC3589 Datasheet - Page 12

• Manufacturer Part Number: LTC3589
• Description: 8-Output Regulator
• Manufacturer: Linear Technology

PIN FUNCTIONS
V
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 I
be bypassed to ground with a 1μF or greater ceramic
capacitor.
LDO3 (Pin 3): Output Voltage of LDO3. Nominal output
voltage is fi xed at 1.8V. This pin must be bypassed to
ground with a 1μF or greater ceramic capacitor.
LDO4 (Pin 4): Output Voltage of LDO4. Output voltages
of 1.8V, 2.5V, 2.8V, and 3.3V are selected via the I
This pin must be bypassed to ground with a 1μF or greater
ceramic capacitor.
V
pin should be bypassed to ground with a 1μF or greater
ceramic capacitor.
PV
Regulator 1. 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 fl 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
fl 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
fl oating.
LTC3589
12
IN_LDO2
IN_LDO34
IN1
2
(Pin 6): Power Input for Step-Down Switching
C register controlled DAC reference. This pin must
(Pin 1): Power Input for LDO2. This pin should
(Pin 5): Power Input for LDO3 and LDO4. This
2
C port.
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
fl 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
fl oating.
PV
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 over
temperature warning and fault conditions. Clear IRQ by
writing to the I
EN_LDO34 (Pin 18): Enable LDO3 and LDO4 Logic Input.
Active high to enable LDO3 and LDO4. Disable LDO4 via
I
OVEN or L2DTV2. A weak pull-down forces EN_LDO34
low when left fl 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 fi 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.
ON (Pin 21): Pushbutton Input. A weak internal pull-up
forces ON high when left fl oating. A normally open push-
button is connected from ON to ground to force a low
state on this pin.
2
C software commands using I
IN4
(Pin 15): Power Input for Switching Regulator 4.
2
C CLIRQ command register.
2
C command registers
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