Cdb4244 – Cirrus Logic CDB4244 User Manual
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DS900DB2
CDB4244
Note that there is a phase reversal on the analog audio output connections of the CDB4244 when using an
active output filter; this is due to the inverting amplifier configurations used in each design. This is noted
along the three-pin differential output headers (see
) by the “+” and “-” labels next to
the headers. There is no phase reversal for either passive filter configuration.
Loads connected to the analog outputs of the CS4244 must satisfy the device’s minimum and maximum
loading requirements. The active output filters that can be realized using the CDB4244 satisfy these require-
ments. However, the user must adhere to the minimum and maximum loading requirements of the CS4244
when connecting an external load to the CDB4244 while using a passive output filter. See
and
to observe the loads already present on the analog outputs of the CS4244
under the passive filter options, as these loads must be taken into account when connecting an external
load to the CDB4244 using a passive output filter. See the CS4244 data sheet for the minimum and maxi-
mum loading specifications of the CS4244.
Refer to AN340: CS4234/4244 Filter Considerations for a detailed discussion of recommended output filters
for the CS4244 as they pertain to the CDB4244. This document details the design decisions and trade-offs
involved with the filters used here. Reference the CS4244 data sheet for the analog output characteristics
of the device.
WARNING: The active differential-to-single-ended filter option places the full differential output voltage of the re-
spective CS4244 analog output pair on a single RCA phono jack. Connect these outputs to external
devices with caution, as this signal level may exceed the maximum allowable input amplitude for many
consumer devices.