SI4844-B20 Datasheet, PDF (14/27 Pages) Silicon Laboratories – BROADCAST ANALOG TUNING DIGITAL DISPLAY AM/FM/SW RADIO RECEIVER

Si4844-B20
4. Functional Description
Figure 4. Si4844-B Functional Block Diagram
4.1. Overview
The Si4844-B is the analog-tuned digital-display digital
CMOS AM/FM/SW radio receiver IC that integrates the
complete receiver function from antenna input to audio
output. Working with an external MCU with LCD/LED
driver, Si4844-B can output the AM/FM/SW
frequencies, band, Bass/Treble and stereo/mono
information to display on LCD/LED, while using a simple
potentiometer at the front end for analog-tune.
Leveraging Silicon Laboratories' proven and patented
digital low intermediate frequency (low-IF) receiver
architecture, the Si4844-B delivers superior RF
performance and interference rejection in AM, FM and
SW bands. The Si4844-B is pin-to-pin compatible with
the current Si484x-A tuning. The Si4844-B shares the
advanced features of the Si484x-A and can support a
wider range of FM and SW bands. It also supports
China TV channels and audio reception in the FM band.
The superior control algorithm integrated in Si4844-B
provides an easy and reliable control interface while
eliminating all the manually tuned external components
used in traditional solutions.
Like other successful audio products from Silicon Labs,
Si4844-B offers unmatched integration and PCB space
savings with minimum external components and small
board area on a single side PCB. The high integration
and complete system production test simplifies design-
in, increases system quality, and improves
manufacturability. The receiver has very low power
consumption, runs off two AAA batteries, and delivers
the performance benefits of high performance digital
radio experience with digital display to the legacy
analog-tuned radio market.
The Si4844-B provides good flexibility in using the chip.
The frequency range of FM/AM/SW bands,
mono/stereo threshold, de-emphasis value, AM tuning
step, AM soft mute level/rate, and Bass/Treble can be
either configured by the MCU or by using external
hardware to make a selection. The reference clock of
the FM tuner can be provided either by the crystal or by
the host MCU within tolerance.
Si4844-B also has flexibility in selecting bands and
configuring band properties, enabling masked Host
MCU for multiple projects, and reducing the cost of
development. Four tuning preferences are available to
meet different tuning preference requirements.
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Rev. 1.0