Overview
The LA3401 is a multifunctional MPX demodulator IC designed for FM stereo electronic tuning. It features the VCO non-adjusting function that eliminates the need to adjust free-running frequency of VCO and the accessory functions such as FM/AM input, FM/AM input changeover, muting.
   
Features
• Non-adjusting VCO : Eliminates the need to adjust freerunning frequency.
• Good temperature characteristic of VCO : ±0.1% typ. for
    ±50°C change.
• Less high frequency distortion of stereo main signal
    (0.07% typ. at f=10kHz) (Non-adjusting PLL makes it
    possible to make the capture range narrower, providing
    less high frequency beat distortion of stereo main signal.)
• Low distortion : Mono 0.01% typ.
                            Main 0.025% typ.
• High S/N : 91dB typ./mono 300mV input, LPF
                    94dB typ./mono 400mV input, LPF
   
Functions
• VCO non-adjusting function.
• PLL MPX stereo demodulator.
• Gain variable type post amplifier.
• FM-AM changeover.
• Muting at the FM-AM changeover mode (changeover
    mute)
• Muting function.
• Drive pin for external muting.
• VCO stop function.
• Separation adjust function.
• Muting at the VCC-ON mode.
   
Applications
• Home stereos, portable hi-fi sets.