SC21150 Datasheet, PDF (17/20 Pages) Semtech Corporation – Tiny 1.2A Synchronous Buck Regulator

SC21150
PCB Layout Guidelines
An optimum layout for the SC21150 is shown below.
When doing the PCB layout the following guidelines
should be used:
The input capacitor must be located as close as possible to
the IC and directly connected to pins A2 (VIN) and A1
(GND).
The LX trace from pin B1 to the inductor should be as
short as possible, and wide to reduce IR loss and improve
heat dissipation.
The output capacitor should be close to the inductor. The
feedback components (Rtop, Ctop, Rbot, for adjustable
VOUT) should be located as close as possible to the FB pin.
For the ground connection to Rbot, use a via to a ground
plane and place another via near the A1 (GND) pin of the
IC.
The FB trace should be short and not routed near noise
signals. Do not route the FB trace under the inductor; the
high impedance of the FB circuit can pick up noise from
the inductor’s magnetic field.
VIN
CIN
GND
FB
LX ^SC21150
L1
COUT
SC21150 PCB Layout
VOUT
17