TP3057V
 Enhanced Serial Interface CODEC/Filter COMBO

The TP3054, TP3057 family consists of µ-law and A-law monolithic PCM CODEC/filters
utilizing the A/D and D/A conversion architecture shown inFigure 1 , and a serial PCM interface.
The devices are fabricated using National’ s advanced double-poly CMOS process microCMOS .

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 µ-law or A-law PCM format. The decode portion of each device
consists of an expanding decoder, which reconstructs the analog signal from the companded µ-law
or A-law code, a low-pass filter which corrects for the sin x/x response of the decoder output
and rejects signals above 3400 Hz followed by a single-ended power amplifier capable
of driving low impedance loads. The devices require two 1.536 MHz, 1.544 MHz or 2.048 MHz transmit
and receive master clocks, which may be asynchronous transmit and receive bit clocks,
which may vary from 64 kHz to 2.048 MHz and transmit and receive frame sync pulses.
The timing of the frame sync pulses and PCM data is compatible with both industry standard formats.

Dokumentacja dostępna pod adresem: http://www.wolumen53.com/pdf/TP3057.pdf