XR-T7296 Datasheet, PDF (7/16 Pages) Exar Corporation – DS3/STS-1, E3 Integrated Line Transmitter

XR-T7296
PULSE SHAPER
The pulse shaper circuit uses a combination of filters and
slew rate control techniques to pre-shape the pulse going
out to the line. The amplitude of the transmit pulse can be
adjusted using the TXLEV (Transmit Level) pin. When the
distance to the cross-connect exceeds 225 ft, TXLEV
should be set high. When the distance is less than 225 ft.
TXLEV should be set low. Setting TXLEV high enables
the transmitter to send out a nominal voltage of 1.0V
peak, and 850mV peak when low. The state of TXLEV pin
has no effect on E3 operation.
TTIP ^36$5%
1:1
75$5%
TRING ^36$5%
1
3
Note
1 _{Transformer = Pulse Engineering PE 65966, PE 65967}
Surface Mount, Same Transformer for DS3, STS-1 and
E3.
Figure 2. Transmit Pulse Amplitude Test Circuit
DRIVER MONITOR
Using TTIP and TRING as input, the driver monitor
detects driver failure by monitoring the activities at MTIP
and MRING. If no signal is detected on these pins for 128
TCLK cycles $32 cycles, DMO will be set high until the
next AMI signal is detected.
Parameter
Turn Ratio
Primary Inductance
Isolation Voltage
Leakage Inductance
Value
1:1
40µH
1500Vrms
0.6µH
Table 1. Transmit Transformer Characteristics
Rev. 2.01
7