LTC3615 Datasheet, PDF (10/32 Pages) Linear Technology – Dual 4MHz, 3A Synchronous Step-Down DC/DC Converter

LTC3615
Pin Functions (FE/UF)
TRACK/SS1 (Pin 21/Pin 24): Internal, External Soft-
Start, External Reference Input for Channel 1. The type
of start-up behavior for channel 1 is programmable with
the TRACK/SS1 pin:
1. Internal soft-start with a fixed timing can be programmed
by tying TRACK/SS1 to SV_IN.
2. External soft-start can be programmed with the timing
set by a capacitor to ground and a resistor to SV_IN.
3. Tracking the start-up behavior of another supply is
programmable (see the Applications Information
section).
4. The pin can be used as external reference input.
ITH1 (Pin 22/Pin 1): Error Amplifier Compensation. Con-
nection for external compensation from ITH to SGND.
The current comparator’s threshold increases with this
control voltage. Tying this pin to SV_IN enables AVP mode
with internal compensation.
V_FB1 (Pin 23/Pin 2): Voltage Feedback Input Pin for
Channel 1. Receives the feedback voltage for channel 1
from the external resistive divider across the output.
MODE (Pin 24/Pin 3): Mode Selection.
1. Tying the MODE pin to SV_IN or SGND enables pulse-
skipping mode or Burst Mode operation (with an internal
Burst Mode clamp), respectively.
2. If this pin is held at slightly higher than half of SV_IN,
forced continuous mode will be selected.
3. Connecting this pin to an external voltage will select
Burst Mode operation with the burst clamp set to the
pin voltage.
PGND (Exposed Pad Pin 25/ Exposed Pad Pin 25): Power
Ground. The exposed pad connects to the sources of the
power N-channel MOSFETs. The PGND pin is common
for both channels. The exposed pad must be soldered
to the PCB.
For electrical connection and rated thermal performance,
refer to the Operation and Applications Information sec-
tions for more information.
3615f
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