Tripath Technology, Inc. - Technical Information
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 amplifiers switching
pattern will degrade the measurement.
One feature of the TA2024B 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 TA2024B 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.
11
TA2024B –KL/1.2/01.06
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
