AK2346A

The AK2346A is an IC that integrates the baseband section of a wireless device with a built-in voice filter, limiter, splatter filter, emphasis, compander, confidential circuit, and MSK modem into a single chip.
The AK2346A has a HPF for voice, shows a high attenuation rate below 250 Hz, and removes the sub audio signal of CTCSS. In addition, a total of four electronic volumes are provided at the first and final stages of the transmitter / receiver, and it is possible to automatically adjust the microphone sensitivity and the sensitivity of the modulator / demodulator under the control of the CPU. 
The AK2346A uses a small 24-pin QNF in the package, which is suitable for downsizing equipment.