THS7102 Datasheet, PDF (3/10 Pages) Texas Instruments – ADSL (POTS) CENTRAL OFFICE LINE INTERFACE DRIVER/RECEIVER

THS7102
ADSL (POTS) CENTRAL OFFICE LINE INTERFACE DRIVER/RECEIVER
functional block diagram
TXEN1 TXEN2
VCCL
SLOS311B− MAY 2000 − REVISED DECEMBER 2001
VCCOP1 VCCOP2
TXINP
TXINN
TXCM
RXOUTP
RXOUTN
RXCM
1BUFIN
1BUFOUT
1.5 kΩ 11.2 kΩ
10.2 kΩ
+
_^{Tx In}
1.5 kΩ 11.2 kΩ
Rx Out
_ ^{Buffer 1}
+
BPF
Tx Out
LPF
Rx P-In ^_
+
VCCL
R
X1
R
Rx M-In ^_
+
Buffer 2 _{_}
+
GND
TXAS2
TXAS1
TXAF
TXBF
TXBS1
TXBS2
RXPO
RXPI
RXPN
RXMO
RXMI
RXMN
2BUFIN
2BUFOUT
BUFEN
VAG
GND
VCCON
The THS7102 is designed to implement full-rate ADSL signals over the same line as POTS signals at the central
office (CO). The THS7102 transmit BPF consists of a low-pass filter and a high-pass filter. The low-pass filter
portion of the BPF is comprised of a third order Chebyshev filter with a 0.33-dB passband ripple and a breakpoint
frequency of 1.3 MHz. The high-pass portion of the BPF is a 0.33-dB passband ripple Chebyshev with a
breakpoint frequency at 151.7 kHz. This high-pass section requires that a 680-pF capacitor be used at each
transmit input (TXINP and TXINN) for the appropriate Chebyshev response. Together the LPF and HPF form
a bandpass filter with a passband ripple of about 0.6 dB. The THS7102 receive LPF is comprised of a fourth
order Chebyshev filter with a 0.25-dB passband ripple and a breakpoint frequency of 146 kHz.
NOTE:
The definition of breakpoint frequency is the frequency at which the attenuation leaves the ripple band.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
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