ltc3586 Linear Technology Corporation, ltc3586 Datasheet - Page 12

• Manufacturer Part Number: ltc3586
• Description: High Ef? Ciency Usb Power Manager With Boost, Buck-boost And Dual Bucks
• Manufacturer: Linear Technology Corporation

LTC3586
EN2 (Pin 20): Digital input. This input enables the buck
switching regulator 2.
EN1 (Pin 21): Digital input. This input enables the buck
switching regulator 1.
V
(Boost). This pin will generally be connected to V
A 1μF MLCC capacitor is recommended on this pin.
FB2 (Pin 23): Feedback Input for (Buck) Switching Regu-
lator 2. When regulator 2’s control loop is complete, this
pin servos to 0.8V.
V
lator 2. This pin will generally be connected to V
A 1μF MLCC capacitor is recommended on this pin.
SW2 (Pin 25): Power Transmission Pin for (Buck) Switch-
ing Regulator 2.
SW1 (Pin 26): Power Transmission Pin for (Buck) Switch-
ing Regulator 1.
V
tor 1. This pin will generally be connected to V
MLCC capacitor is recommended on this pin.
FB1 (Pin 28): Feedback Input for (Buck) Switching Regu-
lator 1. When regulator 1’s control loop is complete, this
pin servos to 0.8V.
PROG (Pin 29): Charge Current Program and Charge
Current Monitor Pin. Connecting a resistor from PROG
to ground programs the charge current. If sufficient in-
put power is available in constant-current mode, this pin
servos to 1V. The voltage on this pin always represents
the actual charge current.
CHRG (Pin 30): Open-Drain Charge Status Output. The
CHRG pin indicates the status of the battery charger. Four
possible states are represented by CHRG: charging, not
charging, unresponsive battery and battery temperature
out of range. CHRG is modulated at 35kHz and switches
between a low and a high duty cycle for easy recogni-
tion by either humans or microprocessors. See Table 3.
CHRG requires a pull-up resistor and/or LED to provide
indication.
PIN FUNCTIONS
12
IN4
IN2
IN1
(Pin 27): Power Input for (Buck) Switching Regula-
(Pin 24): Power Input for (Buck) Switching Regu-
(Pin 22): Power Input for Switching Regulator 4
OUT
. A 1μF
OUT
OUT
.
.
GATE (Pin 31): Analog Output. This pin controls the gate
of an optional external P-channel MOSFET transistor used
to supplement the ideal diode between V
external ideal diode operates in parallel with the internal
ideal diode. The source of the P-channel MOSFET should
be connected to V
to BAT. If the external ideal diode FET is not used, GATE
should be left floating.
BAT (Pin 32): Single Cell Li-Ion Battery Pin. Depending on
available V
deliver power to V
from V
EN4 (Pin 33): Digital input. This input enables the boost
switching regulator 4.
V
PowerPath Controller and Input Voltage of the Battery
Charger. The majority of the portable product should be
powered from V
power between the external load on V
battery charger. Priority is given to the external load and
any extra power is used to charge the battery. An ideal
diode from BAT to V
if the load exceeds the allotted power from V
V
with a low impedance ceramic capacitor.
V
pins deliver power to V
controlled current from a DC source such as a USB port
or wall adapter.
SW (Pin 37): Power Transmission Pin for the USB
Power Path. The SW pin delivers power from V
via the buck switching regulator. A 3.3μH inductor should
be connected from SW to V
FAULT (Pin 38): Bi-directional input/output (open-drain)
used to alert or receive information from other power
management ICs regarding an electrical fault.
Exposed Pad (Pin 39): Ground. The Exposed Pad should
be connected to a continuous ground plane on the second
layer of the printed circuit board by several vias directly
under the LTC3586.
BUS
BUS
OUT
power source is removed. V
(Pins 35, 36): Primary Input Power Pin. These
(Pin 34): Output Voltage of the Switching
OUT
BUS
via the battery charger.
power, a Li-Ion battery on BAT will either
OUT
OUT
OUT
. The LTC3586 will partition the available
OUT
through the ideal diode or be charged
and the drain should be connected
ensures that V
OUT
OUT
via the SW pin by drawing
.
OUT
should be bypassed
OUT
OUT
OUT
is powered even
and the internal
and BAT. The
BUS
BUS
or if the
to V
OUT
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