LTC3672B-1_15 Datasheet, PDF (10/12 Pages) Linear Technology – Monolithic Fixed-Output 400mA Buck Regulator with Dual

LTC3672B-1
APPLICATIONS INFORMATION
PRINTED CIRCUIT BOARD LAYOUT CONSIDERATIONS
When laying out the printed circuit board, the following
list should be followed to ensure proper operation of the
LTC3672B-1:
1) The Exposed Pad of the package should connect directly
to a large ground plane to minimize thermal and electrical
impedance.
2) The connections from the input supply pins (V_IN and V_IN1)
to their respective decoupling capacitors should be kept as
short as possible. The GND side of these capacitors should
connect directly to the ground plane of the part. The V_IN
capacitor provides the AC current to the buck regulator’s
power MOSFETs and their drivers. It is especially important
to minimize PCB trace inductance from this capacitor to
the V_IN and GND pins of the LTC3672B-1.
3) The switching power trace connecting the SW pin to
the inductor should be kept as short as possible to reduce
radiated EMI and parasitic coupling.
4) The LDO output capacitors should be placed as close
to the IC as possible, and connect to the LDO outputs and
the GND pin as directly as possible.
3672B1f
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