BCM4354 Data Sheet
Audio Features
Audio Features
A number of features are implemented in the BCM4354 to provide the best possible audio experience for the
user.
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Mono/Stereo Blend or Switch: The BCM4354 provides automatic control of the stereo or mono settings
based on the FM signal carrier-to-noise ratio (C/N). This feature is used to maintain the best possible audio
SNR based on the FM channel condition. Two modes of operation are supported:
– Blend: In this mode, fine control of stereo separation is used to achieve optimal audio quality over a
wide range of input C/N. The amount of separation is fully programmable. In Figure 21, the separation is
programmed to maintain a minimum 50 dB SNR across the blend range.
– Extended blend: In this mode, stereo separation is maximized across a wide range of input CNR.
Broadcom static suppression typically gives a static-free user experience to within 3 dB of ultimate
sensitivity.
Figure 21: Example Blend/Switch Usage
– Switch: In this mode, the audio switches from full stereo to full mono at a predetermined level to
maintain optimal audio quality. The stereo-to-mono switch point and the mono-to-stereo switch points
are fully programmable to provide the desired amount of audio SNR. In Figure 22, the switch point is
programmed to switch to mono to maintain a 40 dB SNR.
Broadcom®
October 15, 2014 • 4354-DS109-R
Page 63
BROADCOM CONFIDENTIAL
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