LTC3614 LINER [Linear Technology], LTC3614 Datasheet - Page 9

• Manufacturer Part Number: LTC3614
• Description: 4A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter
• Manufacturer: LINER [Linear Technology]

PIN FUNCTIONS
RUN (Pin 19): Enable Pin. Forcing this pin to ground shuts
down the LTC3614. In shutdown, all functions are disabled
and the chip draws <1μA of supply current.
PGOOD (Pin 20): Power Good. This open-drain output is
pulled down to SGND on start-up and while the FB voltage
is outside the power good voltage window. If the FB volt-
age increases and stays inside the power good window
for more than 100μs the PGOOD pin is released. If the
FB voltage leaves the power good window for more than
100μs the PGOOD pin is pulled down.
In DDR mode (DDR = V
in relation to the actual TRACK/SS pin voltage. During up/
down tracking the PGOOD pin is always pulled down.
In shutdown the PGOOD output will actively pull down
and may be used to discharge the output capacitors via
an external resistor.
MODE (Pin 21): Mode Selection. Tying the MODE pin
to SV
Mode operation (with an internal Burst Mode clamp), re-
spectively. If this pin is held at slightly higher than half of
SV
pin to an external voltage between 0.45V and 0.8V selects
Burst Mode operation with the burst clamp set to the pin
voltage. See the Operation section for more details.
IN
, forced continuous mode is selected. Connecting this
IN
or SGND enables pulse-skipping mode or Burst
IN
), the power good window moves
V
feedback voltage from the external resistive divider across
the output.
ITH (Pin 23): Error Amplifi er Compensation. The current
comparator’s threshold increases with this control volt-
age. Tying this pin to SV
and AVP mode.
TRACK/SS (Pin 24): Track/External Soft-Start/External
Reference. Start-up behavior is programmable with the
TRACK/SS pin:
1. Tying this pin to SV
2. External soft-start timing can be programmed with a
3. TRACK/SS can be used to force the LTC3614 to track
The pin can also be used as external reference input. See the
Applications Information section for more information.
PGND (Exposed Pad Pin 25): Power Ground. This pin
connects to the source of the internal N-channel power
MOSFET. This pin should be connected close to the (–)
terminal of C
FB
circuit.
capacitor to ground and a resistor to SV
the start-up behavior of another supply.
(Pin 22): Voltage Feedback Input Pin. Senses the
IN
and C
OUT
IN
IN
.
enables internal compensation
selects the internal soft-start
LTC3614
IN
.
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