BL1302A57

The BL1302A57 S is an A-law monolithic PCM CODEC Filter which has the A/D and D/A conversion and a serial PCM Interface The device is fabricated using the advanced double-poly nwell CMOS process. It is pin compatible with TP3057. The encode portion of each device consists of an input gain adjust Amplifier an active RC pre-filter which eliminates very high frequency noise prior to entering a switched-capacitor band-pass Filter that rejects signals below 200 Hz and above 3400 Hz. Also included are auto-zero circuitry and a companding coder which samples the filtered signal and encodes it in the companded A-law PCM format. The decode portion consists of an expanding decoder, which reconstructs the By Shanghai Belling Co, Ltd