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Power Analog Microelectronics Inc

08/2008 Rev 1.2

PAM8610

10W Stereo Class-D Audio Power Amplifier with DC Volume Control

www.poweranalog.com

Heat Dissipation in PCB design

Dual-Side PCB

4-layer PCB

Consideration for EMI

Generally, class-D amplifiers are high efficiency

and need no heat sink. For high power ones that

has high dissipation power, the heat sink may also

not necessary if the PCB is carefully designed to

achieve good heat

by the PCB itself.

To achieve good heat

, the PCB’s

copper plate should be thicker than 0.035mm and

both sides of the PCB should

be utilized for heat sink.

The thermal pad on the bottom of the device

should be soldered to the plate of the PCB, and

via holes, usually 9 to 16, should be drilled in the

PCB area under the device and deposited copper

on the vias should be thick enough so that the

heat can be dissipated to the other side of the

plate. There should be no insulation mask on the

other side of the copper plate. It is better to drill

more vias

around the device if

possible.

If it is 4-layer PCB, the two middle layers of

grounding and power can be employed for heat

dissipation, isolating them into serval islands to

avoid short between ground and power.

dissipation

dissipation

the copper plate on

on the PCB

Filters are not required if the traces from the

amplifier to the speakers are short (<20cm). But

most applications require a ferrite bead filter as

shown in below figure. The ferrite bead filter

reduces EMI of around 1MHz and higher to meet

the

F CC

and

CE's

requirements.

It

is

recommended to use a ferrite bead with very low

impedances at low frequencies and high

impedance at high frequencies (above 1MHz).

The EMI characteristics are as follows after

employing the ferrite bead.

Vertical Polarization

Horizontal Polarization

200pF

200pF

OUT+

OUT-

Ferrite Bead

Ferrite Bead

OUTP

OUTN