T7281

The T7281 is a kind of adaptive differential pulse-code modulation (ADPCM) transcoder. It is a single-chip integrated circuit that digitally reencodes 64 kbits/s PCM (8 kHz sampling) to ADPCM at various bit rates. The T7281 provides 16 channels of encoding or decoding, any one of which can function as either an encoder or decoder, independent of the other channels. It is available in a 24-pin, plastic DIP or in a 44-pin, plastic, leaded chip carrier (PLCC).

There are some features of T7281 as follows: (1)ADPCM coding and decoding with bypass processing; (2)-law and A-law 64 kbits/s PCM compatible; (3)ANSI and CCITT G.726 compatible at 40 kbits/s, 32 kbits/s, 24 kbits/s, and 16 kbits/s; (4)variable-rate ADPCM, coding at 40 kbits/s, 32 kbits/s, 24 kbits/s, and 16 kbits/s and 8 kbits/s; (5)16-channel implementation (M encoders and N decoders, where M+N=16 channels); (6)independent feature control on a per-channel, 125s time-slot basis; (7)reset of internal memory states under user control; (8)pin-for-pin replacement for T7280.

The following is about the absolute maximum ratings about T7281: (1)DC supply voltage, VDD: -0.5 to 6.5 V; (2)power dissipation, Pdis: 600 mW max; (3)storage temperature, Tstg: -55 to +125.