Tripath Technology, Inc. – Preliminary Technical Information

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TPS4100 – KL/Rev. 2.5/02.05

manufactured as common mode chokes with the windings wound in the same direction or as differential

mode chokes with the windings wound in opposite directions. Since the ferrite reduces the energy storage

capability of the inductor, it is important to ensure that the shielded dual inductor does not saturate at the

maximum currents attainable by the TPS4100. Dual inductors wound as common mode inductors may

aid in reducing common mode noise to the load. They also may result in lower than initial inductances

due to electric field cancellation effects.

Tripath also recommends that an RC damper be used after the LC low-pass filter. No-load operation of a

TPS4100 amplifier can create significant peaking in the LC filter, which produces strong resonant currents

that can overheat the integrated MOSFETs and/or other components. The RC dampens the peaking and

prevents problems.

It is highly recommended that the design process for a TPS4100 amplifier include an analysis of the

interaction of intended speaker(s) with the LC filter and RC damper to ensure the desired frequency

response is attained. Component values for the LC filter and RC damper may need to be altered from the

Tripath suggestions to achieve the required response.