TP3040 Datasheet, PDF (1/10 Pages) National Semiconductor (TI) – TP3040, TP3040A PCM Monolithic Filter

September 1994
TP3040 TP3040A PCM Monolithic Filter
General Description
The TP3040 TP3040A filter is a monolithic circuit contain-
ing both transmit and receive filters specifically designed for
PCM CODEC filtering applications in 8 kHz sampled sys-
tems
The filter is manufactured using microCMOS technology
and switched capacitor integrators are used to simulate
classical LC ladder filters which exhibit low component sen-
sitivity
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 pro-
vides a flat response in the passband and rejection of sig-
nals below 200 Hz and above 3 4 kHz
RECEIVE FILTER STAGE
The receive filter is a fifth order elliptic low pass filter de-
signed to reconstruct the voice signal from the decoded de-
multiplexed signal which as a result of the sampling pro-
cess is a stair-step signal having the inherent sin x x fre-
quency response The receive filter approximates the func-
tion required to compensate for the degraded frequency re-
sponse and restore the flat passband response
Features
Y _{Designed for D3 D4 and CCITT applications}
Y a_5V b_{5V power supplies}
Y _{Low power consumption}
45 mW (0 dBm0 into 600X)
30 mW (power amps disabled)
Y _{Power down mode 0 5 mW}
Y _{20 dB gain adjust range}
Y _{No external anti-aliasing components}
Y _{Sin x x correction in receive filter}
Y _{50 60 Hz rejection in transmit filter}
Y _{TTL and CMOS compatible logic}
Y _{All inputs protected against static discharge due to}
handling
Block Diagram
FIGURE 1
C1995 National Semiconductor Corporation TL H 6660
TL H 6660 – 1
RRD-B30M115 Printed in U S A