BA1442A Datasheet, PDF (1/17 Pages) Rohm – AM radio / FM IF stereo system IC

Audio ICs
AM radio / FM IF stereo system IC
BA1442A
The BA1442A is an AM radio and FM IF stereo system IC developed for radio cassette players. The FM circuit is com-
prised of a differential IF amplifier, a double-balance type quadrature detector, and a PLL-type stereo MPX circuit. The
AM circuit is comprised of a local oscillator, a double-balanced mixer, an IF amplifier, a detector, and an AGC circuit.
FApplications
Radio cassette players
FFeatures
1) The “S” curve characteristic of the FM detector can
be used for upper heterodyne (“N” curve) operation.
2) Audio high cut and low cut can be used to improve the
AM fidelity.
3) A reference voltage supply is provided to ensure
good frequency stability in the shortwave bands.
4) Good FM stability.
5) Built-in damping resistor (3.3kΩ) for the quadrature
coil.
6) The FM MPX uses a Laser Locked Loop, making
adjustment of the VCO and addition of external
components unnecessary.
7) Built-in forced monaural function for the MPX (VCO
stops, LED off).
8) VCO of the MPX is switched off during AM opera-
tion.
9) The stereo indicator pin has a constant drive cur-
rent, and a current limiting resistor is not required.
10) Few external components required.
FAbsolute maximum ratings (Ta = 25_C)
FRecommended operating conditions (Ta = 25_C)
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