TECHNICA L INFORMA T ION

TA2024 Preliminary, Rev. 1.0

Page 11

Performance Measurements of the TA2024

The TA2024 operates by generating a high frequency switching signal based on the audio input. This

signal is sent through a low-pass filter (external to the Tripath amplifier) that recovers an amplified

varies between 100kHz and 1.0MHz, which is well above the 20Hz – 20kHz audio band. The pattern

itself does not alter or distort the audio input signal but it does introduce some inaudible components.

The measurements of certain performance parameters, particularly noise related specifications such

as THD+N, are significantly affected by the design of the low-pass filter used on the output as well as

the bandwidth setting of the measurement instrument used. Unless the filter has a very sharp roll-off

just beyond the audio band or the bandwidth of the measurement instrument is limited, some of the

inaudible noise components introduced by the Tripath amplifier switching pattern will degrade the

measurement.

One feature of the TA2024 is that it does not require large multi-pole filters to achieve excellent

performance in listening tests, usually a more critical factor than performance measurements.

Though using a multi-pole filter may remove high-frequency noise and improve THD+N type

measurements (when they are made with wide-bandwidth measuring equipment), these same filters

degrade frequency response. The TA2024 Evaluation Board uses the Test/Application Circuit in this

data sheet, which has a simple two-pole output filter and excellent performance in listening tests.

Measurements in this data sheet were taken using this same circuit with a limited bandwidth setting in

the measurement instrument.