TAS5624A

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SLAS844A – MAY 2012 – REVISED JANUARY 2016

Layout Guidelines (continued)

above mounting areas that contact the PCB surface. It must be supported mechanically at each end of the IC.

This mounting ensures the correct pressure to provide good mechanical, thermal and electrical contact with

TAS5624A PowerPAD. The PowerPAD contact area must be bare and must be interfaced to the PowerPAD

with a thin layer (about 1 mill) of a thermal compound with high thermal conductivity.

12.1.4.2 Printed-Circuit-Board Requirements

PCB layout, audio performance, EMC, and reliability are linked closely together, and solid grounding improves

results in all these areas. The circuit produces high, fast-switching currents, and take care controlling current flow

and minimizing voltage spikes and ground bounce at IC ground pins. Critical components must be placed for

best performance and PCB traces must be sized for the high audio currents that the IC circuit produces.

Grounding: ground planes must be used to provide the lowest impedance and inductance for power and audio

signal currents between the IC and its decoupling capacitors, LC filters and power supply connection. The area

directly under the IC must be treated as central ground area for the device, and all IC grounds must be

connected directly to that area. A matrix of vias must be used to connect that area to the ground plane. Ground

planes can be interrupted by radial traces (traces pointing away from the IC), but they must never be interrupted

by circular traces, which disconnect copper outside the circular trace from copper between it and the IC. Top and

bottom areas that do not contain any power or signal traces must be flooded and connected with vias to the

ground plane.

Decoupling capacitors: high-frequency decoupling capacitors must be located within 2 mm of the IC and

connected directly to PVDD and GND pins with solid traces. Vias must not be used to complete these

connections, but several vias must be used at each capacitor location to connect top ground directly to the

ground plane. Placement of bulk decoupling capacitors is less critical, but they still must be placed as close as

possible to the IC with strong ground return paths. Typically the heat sink sets the distance.

LC filters: LC filters must be placed as close as possible to the IC after the decoupling capacitors. The capacitors

must have strong ground returns to the IC through top and bottom grounds for effective operation.

PCB copper must be at least 1-oz. thickness. PVDD and output traces must be wide enough to carry expected

average currents without excessive temperature rise. PWM input traces must be kept short and close together on

the input side of the IC and must be shielded with ground flood to avoid interference from high power switching

signals.

The heat sink must be grounded well to the PCB near the IC, and a thin layer of highly conductive thermal

compound (about 1 mill) must be used to connect the heat sink to the PowerPAD.

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