TP3057WM - "Enhanced'' Serial Interface CODEC/Filter COMBO Family
DataSheet
General Description
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 in Figure 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.
Features
- Complete CODEC and filtering system (COMBO) including:
- µ-law, 16-pin - TP3054
- A-law, 16-pin - TP3057
- Designed for D3/D4 and CCITT applications
-
± 5V operation
- Low operating power - typically 50 mW
- Power-down standby mode - typically 3 mW
- Automatic power-down
- TTL or CMOS compatible digital interfaces
- Maximizes line interface card circuit density
- Dual-In-Line or surface mount packages
- See also AN-370, ``Techniques for Designing with CODEC/Filter COMBO Circuits''