THS7103 Datasheet, PDF (3/9 Pages) Texas Instruments – ADSL (ISDN) CENTRAL OFFICE LINE INTERFACE DRIVER/RECEIVER

THS7103
functional block diagram
TXEN1 TXEN2
VCCL
SLOS387 − DECEMBER 2001
VCCOP1 VCCOP2
TXINP
TXINN
TXCM
RXOUTP
RXOUTN
RXCM
1BUFIN
1BUFOUT
1.5 kΩ 11.2 kΩ
9.16 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 THS7103 is designed to implement ADSL signals over the same line as ISDN signals at the central office
(CO). The THS7103 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 268 kHz. This high-pass section requires that a 390-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 THS7103 receive LPF is comprised of a fourth
order Chebyshev filter with a 0.25-dB passband ripple and a breakpoint frequency of 238 kHz.
NOTE:
The definition of breakpoint frequency is the frequency at which the attenuation leaves the ripple band.
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