Overview
The LA1837 is a single-chip AM/FM IF and MPX IC that supports electronic tuning and was developed for use in home stereo systems. It is optimal for use in automatic station selection systems that use the SD and IF counting techniques.

FEATUREs
• On-chip MPX VCO (no external components required)
• Adjacent channel interference rejection function (third and fifth order)
• Supports both the SD and the IF counting techniques.
• The AM and FM SD sensitivities can be set independently.
• The AM and FM output levels can be set independently.
• Improved AM practical sensitivity and high-input  distortion characteristics

Functions
    AM: RF  amplifier, mixer, oscillator, IF amplifier,  detector AGC, oscillator buffer, S-meter, narrowband SD, IF buffer
    FM IF: IF amplifier, quadrature detector, S-meter, Scurve detector, IF buffer output
    MPX: PLL stereo decoder, stereo display, forced mono,  VCO stop, post amplifier, audio muting, adjacent  channel interference rejection function