Refer to
Section 8.3.2 for the following
guidelines:
- PVDD decoupling capacitors,
A. The 100nF capacitors are placed on the same layer and very close
to the device, with the ground return close to the PGND pins. The 1μF capacitors
can be placed on the back of the PCB.
- Traces that carry large currents
incorporate multiple vias, B, to reduce the series impedance of these
traces.
- A ground plane, C, on the
same side as the device pins, helps reduce EMI by providing a very-low loop
impedance for the high-frequency switching current. This plane has many vias
between the ground planes on other layers.
- The ground connections for the
capacitors in the LC filter, D, have a direct path back to the device and
also the ground return for each channel is the shared. This direct path allows
for improved common mode EMI rejection. This is on the same layer of the PCB as
the TAS6754-Q1.
- OUT_xP inductor, OUT_xP to OUT_xM
capacitor, and the OUT_xM to GND capacitor, E, need to have minimum loop
size, starting from the device’s OUT pin to GND pins. These are the switching
related PCB traces. The loop size directly influences the electric field
coupling.
- Heat sink mounting screws,
F, are close to the device to keep the loop short from the package to
ground, providing a low impedance trace for the high frequency noise coupled
into the heat sink back to the PCB.
- Decoupling capacitors, G,
at PLL_BYP, VR_DIG_BYP, VR_DIG_RET, AVDD_BYP, AVDD_RET, VREG_BYP, VREG_RET,
GVDD_BYP, DVDD, are placed on the same layer with device, without affecting the
return path from the LC filter, D.
- PVDD supply trace, H, is suggested to be placed on an internal layer, and
symmetrical to the channels on both sides of the device.
- Device output trace, I, is suggested to be placed on an internal layer,
and symmetrical on both sides of the device.