TP3040

TP3040 TP3040A PCM Monolithic Filter September 1994 TP3040 TP3040A PCM Monolithic Filter General Description The TP3040 TP3040A filter is a monolithic circuit containing both transmit and receive filters specifically designed for PCM CODEC filtering applications in 8 kHz sampled systems The filter is manufactured using microCMOS technology and switched capacitor integrators are used to simulate classical LC ladder filters which exhibit low component sensitivity TRANSMIT FILTER STAGE The transmit filter is a fifth order elliptic low pass filter in series with a fourth order Chebyshev high pass filter It provides a flat response in the passband and rejection of signals below 200 Hz and above 3 4 kHz RECEIVE FILTER STAGE The receive filter is a fifth order elliptic low pass filter designed to reconstruct the voice signal from the decoded demultiplexed signal which as a result of the sampling process is a stair-step signal having the inherent sin x x frequency response The receive filter approximates the function required to compensate for the degraded frequency response and restore the flat passband response Features Y Y Y Y Y Y Y Y Y Y Designed for D3 D4 and CCITT applications a 5V b 5V power supplies Low power consumption 45 mW (0 dBm0 into 600X) 30 mW (power amps disabled) Power down mode 0 5 mW 20 dB gain adjust range No external anti-aliasing components Sin x x correction in receive filter 50 60 Hz rejection in transmit filter TTL and CMOS compatible logic All inputs p...