PCM Repeater. XR-C262Z Datasheet

XR-C262Z Repeater. Datasheet pdf. Equivalent


Exar XR-C262Z
XR-C262Z
High-Performance PCM Repeater
GENERAL DESCRIPTION
FUNCTIONAL BLOCK DIAGRAM
The XR-C262Z is a high-performance monolithic repeater
IC for pulse-code modulated (PCM) telephone systems. It is
designed to operate as a regenerative repeater at 1.544
Megabits per second (Mbps) data rate on T1-type PCM
lines.
PREAMP
OUT
The X R-C262Z operates with a single 6.8 volt power
supply, and with a typical supply current of 13 mA. It
provides bipolar output drive with high-current handlinq
capability. The clock-extractor section of XR-C262Z uses
the resonant-tank circu it principle, rather than the injec-
tion-locked oscillator technique used in earlier monolithic
repeater designs. The bipolar output drivers are designed to
go to their "off" state automatically, when there is no
input signal present.
- SIGNAL
IN
ANALOG
GROUND
+ SIGNAL
IN
ALBO
FILTER
DIGITAL
Vee
- DATA
OUT
FEATURES
Contains all Necessary Active Components
of a PCM Repeater
Uses L-C Tank for Clock Recovery
Low-Voltage Operation (6.8 voltsl
Low-Current Drain (13 mA, typicall
High-Current Bipolar Output Drivers
On-Chip ALBO Port
Automatic Zero-I nput Shutdown
Increased Reliability Over Discrete Designs
2 Megabit Operation Capability
Pin-to-Pin Compatible with XR-C262 with Improved
Switching Characteristics
APPLICATIONS
PCM Repeater for Tl Systems
PCM Repeater for 2 M Bit/s Systems
ABSOLUTE MAXIMUM RATINGS
Storage Temperature
-65°C to +150°C
Operating Temperature
-40°C to +85°C
Supply Voltage
-0.5 to +10 V
Input Voltage (Except Pin 6.7)
-0.5 to +7 V
Input Voltage (Pin 6.7)
-0.5 to +0.5 V
Data Output Voltage (Pin 9,111
+20 V
Voltage Surge (Pin 3,5,9,11) (10 msec only)
50 V
ALBO
TAP
ANALOG
Vee
DIGITAL
GROUND
+ DATA
OUT
SYSTEM DESCRIPTION
The XR-C262Z contains all the active functions required to
build one side of a T1 or 2 M bit/s PCM repeater. T1 is the
most widely used rCM transmission system, operating at
1.544 M bit/so It can operate on either pulp or plastic insu-
lated twisted pair cables. Although the cable gauge may
vary, the total cable loss should not exceed 36 dB at 772
kHz. For a 22 gauge pulp insulated cable and a bit error
rate (BER) of less than 10-6, the max allowable repeater to
repeater spacing is about 6300 feet.
Bipolar PCM signal is attenuated and dispersed in time
as it travels along a transmission cable. This signal, when
received, is amplified and reconstructed by the preampli-
fier automatic line build out (ALBO). clock and data
threshold detector circuits contained within the XR-C262Z.
Amplitude equalization and frequency spectrum shaping is
achieved through the variable impedance of the ALBO
ports and its associated ALBO network.
Incoming pulse stream is full wave rectified and timing
information is extracted by the clock threshold detector.
Clock recovery is then achieved by pulsing a tank circuit
tuned to 1.544 MHz.
ORDERING INFORMATION
Part Number
XR-C262Z
Package
Ceramic
Operating Temperature
-40°C to +85°C
Data is sampled and stored in the output data latches. Buf-
fer drivers are then enabled to produce precisely timed out-
put pulses whose width and time of occurence are control-
led by the regenerated clock signal.
2-30


XR-C262Z Datasheet
Recommendation XR-C262Z Datasheet
Part XR-C262Z
Description High-Performance PCM Repeater
Feature XR-C262Z; XR-C262Z High-Performance PCM Repeater GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM The XR-C262Z.
Manufacture Exar
Datasheet
Download XR-C262Z Datasheet




Exar XR-C262Z
XR-C262Z
ELECTRICAL CHARACTERISTICS
Test Conditions: +VCC "" 6.8 V, TA "" -40°C to +85°C, unless specified otherwise.
PARAMETERS
MIN TYP MAX UNIT
CONDITIONS
SUPPLY CURRENT
Digital Current
Analog Current
Total Current
6 10 13 mA Measured at Pin 12
1.5 3.5 5 mA Measured at Pin 8
13 15 mA
PREAMPLIFIER
Input Offset Voltage
-15
+15 mV Measured betweeQ Pins 3 & 5
Open Loop Gain
58 69 76 dB
Output High Level
4.3
V Measured at Pin 1
Output Low Level
0.8 V Measured at Pin 1
CLOCK RECOVERY SECTION
Clock Drive Swing (High) 5.1
V Measuredat Pin 13
Clock Drive Swing (Low)
4.0 V Measured at Pin 13
Clock Bias
3.8 4
V Measured at Pin 15
Clock Source Input Cur~'ent
0.5 4 IlA Measured at Pin 16
COMPARATOR THRESHOLDS
A LBO Threshold
Clock Threshold
Data Threshold
0.75
0.9
1.1
0.323 0.4 0.517
0.323 0.4 0.517
V
V
V
Measured at Pin 1 relative to Pin 14
INTERNAL REFERENCE VOLTAGES
Reference Voltage
Divider Center Tap
5.0
5.45
5.65
2.5
2.78
2.85
V
V
Measured at Pin 2
Measured at Pin 14
ALBO SECTION
Off Voltage
On Voltage
On Impedance
Filter Drive Current
10 75 mV Measured at Pin 7
1.2 1.7 V Measured at Pin 7
15 n Measured at Pin 7
0.7 1
3 mA Drive Current available at Pin 6
OUTPUT DR IVER SECTION
Measured at Pins 9 & 11
Output High Swing
5.9 6.8
V RL"" 400n
Output Low Swing
0.5 0.7 1.0 V
IL"" 15 mA
Leakage Current
100 IlA
Measured with output in off state
Output Pulse Width
298 324 350 nsec
Output Rise Time
80 nsec
Output Fall Time
80 nsec
Pulse Width Unbalance
15 nsec
2-31







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