Rohm BA1449F Am radio / fm if stereo system ic Datasheet

Audio ICs
AM radio / FM IF stereo system IC
BA1448S / BA1449F
The BA1448S and BA1449F are electronic tuning system ICs for AM, FM IF, and MPX. They have been developed for
use in radio cassette players and mini-component stereo systems.
The FM detector and MPX VCO circuits do not require adjustment, which will reduce the number of assembly line processes. In particular, the VCO is laser locked, and requires no adjustment or external components. The characteristics
of the two chips are the same, but the packages are different (24-pin SDIP for the BA1448S and 24-pin SOP for the
BA1449F).
Applications
Synthesized tuners in radio cassette players and minicomponent stereo systems.
Features
1) Built-in mono AM radio, FM IF amplifier / detector,
and FM stereo demodulator.
2) DTS compatible (both SD and IF count).
3) Built-in reference voltage supply for good short-wave
band frequency stability.
4) Good FM stability.
5) FM detector does not require adjustment (ceramic
discriminator).
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
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6) FM MPX VCO is laser locked and requires no adjustment or external components.
7) Built-in forced monaural function for the MPX (VCO
stops, LED off).
8) Audio can be low-cut to improve AM fidelity.
9) VCO for the MPX switches off during AM operation.
10) Mute possible for IF request.
Audio ICs
BA1448S / BA1449F
Block diagram
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Audio ICs
Input / output circuits
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BA1448S / BA1449F
Audio ICs
BA1448S / BA1449F
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Audio ICs
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BA1448S / BA1449F
Audio ICs
BA1448S / BA1449F
Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 5V)
Signal source FM IF MPX: fIN = 10.7MHz, 1kHz modulation 22.5kHz dev (30%),
Signal source FM IF MPX fIN = 10.7MHz, 19kHz modulation 7.5kHz dev (10%)
Signal source AM IF MPX: fIN = 1000kHz, 1kHz modulation 30%
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Audio ICs
Measurement circuit
360
BA1448S / BA1449F
Audio ICs
BA1448S / BA1449F
Application example
Electrical characteristic curves
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Audio ICs
External dimensions (Units: mm)
362
BA1448S / BA1449F
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