This post explains for the semiconductor KT0803L.
The Part Number is KT0803L.
The function of this semiconductor is Monolithic Digital Stereo FM Transmitter.
Preview images :
Monolithic Digital Stereo FM Transmitter Radio-Station-on-a-Chip™ KT0803L Features Hardware compatible with KT0803K and KT0803M Additional features to KT0803K and KT0803M Software standby; Automatic power down power amplifier when silence is detected; Multiple reference clock support including from 32.768KHz to 26MHz; ALC (Automatic Level Control) Higher SNR (Stereo: 66dB) Increased audio frequency response Software controlled XTAL selection Professional Grade Performance: SNR ≥ 66 dB Stereo Separation > 40 dB International compatible 70MHz ~ 108MHz Ultra-Low Power Consumption: < 17 mA operation current < 3 µA standby current Simple Interface: Single power supply 2 Standard 2-wire I C MCU interface Advanced Digital Audio Signal Processing: On-chip 20-bit ΔΣ Audio ADC On-chip DSP core On-chip 24dB PGA with optional 1dB step Automatic calibration against process and temperature 1.6V ~ 3.6V supply Programmable transmit level Programmable pre-emphasis (50/75 µs) Pb-free and RoH [...]