Design guidelines for PCB schematic and layout

AN4189

10/23

Doc ID 023809 Rev 1

frequency, which must be chosen between the upper limit of the audio band (~ 20 kHz)

and the carrier frequency (384 kHz), otherwise the frequency response is affected.

3.

The purpose of the damping network is to avoid the high-frequency oscillation issue on

the output circuit. It can also improve THD and avoid the inductive copper on the PCB

route when the system is working in high frequency with PWM or PCM.

Snubber filter

The snubber circuit must be optimized for the application. Starting values are 330 pF in

series to 22 ohm. The power on this network can be defined by the following formula which

considers the power supply, frequency and capacitor value:

This power is dissipated on the series resistance.

Figure 9.

Snubber filter

Damping network

The C-R-C is a damping network and is mainly intended for high inductive loads.

Figure 10.

Damping network

C126

330 p

R44

22

INxA

INxB

C damp-S

C damp-P

C damp-P

C damp-S

R damp

R damp