2.0 Circuit Description
Bt8370/8375/8376
2.9 Transmit Line Interface Unit
Fully Integrated T1/E1 Framer and Line Interface
2.9 Transmit Line Interface Unit
The Transmit Line Interface Unit (TLIU), illustrated in Figure 2-33, converts P
and N rail NRZ data to AMI pulses. The P and N rail NRZ data is generated by
the XMTR, converted to AMI bipolar pulses by the TLIU, and output on the
transmit tip and ring pins, XTIP and XRING. The TLIU has a configurable line
rate, pulse shape, Line Build Out (LBO), external termination resistor, and
transformer turns ratio.
The TLIU consists of a control circuit, a pulse template ROM, a set of LBO
filters, a Digital-to-Analog Converter (DAC), and a line driver.
Figure 2-33. TLIU Diagram
To JAT
Analog Loopback
From JAT
TCKO
8x
TPLL
XTIP
XRING
XOE
LBO
Filters
Pulse
Shape
AIS
Gen
DRV
DAC
TPOS
TNEG
NOTE(S): LBO filter block is not present in short haul devices: Bt8375 and Bt8376.
2-68
Conexant
N8370DSE
CONEXANT [ CONEXANT SYSTEMS, INC ]
