MIC2875 Datasheet, PDF (17/24 Pages) Microchip Technology – 4.8A ISW, Synchronous Boost Regulator with Bi-Directional Load Disconnect

8.0 PCB LAYOUT GUIDELINES
PCB layout is critical to achieve reliable, stable and
efficient performance. A ground plane is required to
control EMI and minimize the inductance in power,
signal and return paths. The following guidelines
should be followed to ensure proper operation of the
device. Please refer to the MIC2875 evaluation board
document for the recommended components
placement and layouts.
8.1 Integrated Circuit (IC)
• Place the IC close to the point-of-load.
• Use fat traces to route the input and output power
lines.
• Analog grounds and power ground should be kept
separate and connected at a single location at the
PCB pad for exposed pad of the IC.
• Place as much as thermal vias on the PCB pad
for exposed pad and connected it to the ground
plane to ensure a good PCB thermal resistance
can be achieved.
8.2 IN Decoupling Capacitor
• The IN decoupling capacitor must be placed close
to the IN pin of the IC and preferably connected
directly to the pin and not through any via. The
capacitor must be located right at the IC.
• The IN decoupling capacitor should be connected
as close as possible to AGND.
• The IN terminal is noise sensitive and the
placement of capacitor is very critical.
8.3 V_IN Power Path Bulk Capacitor
• The V_IN power path bulk capacitor should be
placed and connected close to the V_IN supply to
the power inductor and the PGND of the IC.
• Use either X5R or X7R temperature rating
ceramic capacitors. Do not use Y5V or Z5U type
ceramic capacitors.
8.4 Inductor
• Keep both the inductor connections to the switch
node (SW) and input power line short and wide
enough to handle the switching current. Keep the
areas of the switching current loops small to
minimize the EMI problem.
• Do not route any digital lines underneath or close
to the inductor.
• Keep the switch node (SW) away from the noise
sensitive pins.
• To minimize noise, place a ground plane
underneath the inductor.
MIC2875
8.5 Output Capacitor
• Use wide and short traces to connect the output
capacitor as close as possible to the OUT and
PGND pins without going through via holes to
minimize the switching current loop during the
main switch off cycle and the switching noise.
• Use either X5R or X7R temperature rating
ceramic capacitors. Do not use Y5V or Z5U type
ceramic capacitors.
 2015 Microchip Technology Inc.
DS20005549A-page 17