XRT56L22 Datasheet, PDF (6/16 Pages) Exar Corporation – Low Power Repeater/Receiver

XR-T56L22
ELECTRICAL CHARACTERISTICS (CONT’D)
Parameter
Pin
Min. Typ. Max. Unit
Clock Output Stage
Output Pulse Rise Time (Tr)
11
40
ns
Output Pulse Fall Time (Tf)
11
40
ns
Output Pulse Width (Tw)
11
224
264
ns
Shunt Regulator
Output Voltage
12
4.85
5.1
5.35
V
Voltage Regulation Over Temp.
12
-0.02
%/°C
Load Regulation
12
0.027 %/mA
Note
1 _{Using a 2K pull up resistor between 11 and VCC and 15pF capacitance to GND.}
Conditions
1
Pin 13, 14 floating
Pin 13, 14 floating
1mA to 100mA load
ABSOLUTE MAXIMUM RATINGS
Storage Temperature . . . . . . . . . . . . . . -65°C to 150°C
Operating Temperature . . . . . . . . . . . . . -40°C to 85°C
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . -0.5 to 7V
Supply Voltage Surge (10ms) . . . . . . . . . . . . . . . . . 25V
Data Output Voltage (pin 9, 10) . . . . . . . . . . . . . . . 12V
SYSTEM DESCRIPTION
With reference to the functional block diagram, the basic
operation of the XR-T56L22 may be described as follows:
The received bipolar signal, is applied to a linear amplifier
and automatic equalizer. These circuits provide the
necessary amount of gain and phase equalization to
recover the transmitted data, and band limit the signal, to
optimize repeater performance for near-end crosstalk
produced by other systems operating within the same
cable bundle.
The preamplifier output signals which are balanced and of
opposite phase, are applied to the clock extraction and
pulse regenerator circuits. Here they are rectified and
then applied to a high Q resonant circuit which extracts
the 1.544/2.048 Mbps frequency component from the
received signal. This signal is then sliced and fed to an
adjustable phase shift circuit. A second slicer is used to
control the time at which the output signals from the
preamplifier are sampled by the pulse regenerator
circuits. The phase shifted clock signal is made available
as an output from the circuit for interface applications. The
clock phase adjustment is performed with a single pin
using an external resistor. Adjustment of the position of
the clock sampling edge by the phase shift circuit allows
performance of the pulse regenerator to be optimized.
The pulse regenerator performs the sampling and data
slicing to regenerate the appropriate output pulse. These
pulses are applied to an external output transformer to
create the bipolar signal that drives the next section of
twisted pair.
Rev. 1.02
6