DS21Q50L+ Maxim Integrated Products, DS21Q50L+ Datasheet - Page 59

• Manufacturer Part Number: DS21Q50L+
• Description: IC TXRX E1 QUAD 100-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS21Q50L+

• Function: Transceiver
• Interface: E1
• Number Of Circuits: 4
• Voltage - Supply: 3.14 V ~ 3.47 V
• Current - Supply: 230mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: *
• Includes: AIS Alarms Detector and Generator, Loopback Functions, PRBS Generator / Detector, Remote Detector and Generator
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -

16.4 Transmit Waveshaping and Line Driving
The DS21Q50 uses a set of laser-trimmed delay lines with a precision digital-to-analog converter (DAC)
to create the waveforms that are transmitted onto the E1 line. The waveforms meet the ITU G.703
specifications
programming the L2/L1/L0 bits in the LICR. The DS21Q50 can be set up in a number of various
configurations, depending on the application
Table 16-3. Line Build-Out Select in LICR
*NM = Not Meaningful (return loss value too low for significance).
**Refer to Application Note 336: Transparent Operation on T1, E1 Framers and Transceivers for details on E1 line interface design.
Because of DS21Q50 transmitter’s design, very little jitter (less than 0.005 UI
100kHz) is added to the jitter present on TCLK (or source used for transmit clock). The waveform created
is independent of the duty cycle of TCLK. The transmitter in the device couples to the E1 transmit-
shielded twisted pair or coax through a 1:2 step-up transformer, as shown in
to create the proper waveforms, the transformer must meet the specifications listed in
line driver in the device contains a current limiter that prevents more than 50mA (RMS) from being
sourced in a 1Ω load.
Table 16-4. Transformer Specifications
L2
0
0
0
0
1
Intertwining Capacitance
Leakage Inductance
SPECIFICATION
Primary Inductance
L1
0
0
1
1
0
DC Resistance
Turns Ratio
L0
0
1
0
1
0
(Figure
75W with protection resistors
75W with high return loss
120W with protection
APPLICATION
16-4). The user selects which waveform is to be generated by properly
120W normal
75W normal
resistors
1:1 (receive) and 1:2 (transmit) ±3%
RECOMMENDED VALUE
600mH minimum
1.0mH maximum
40pF maximum
1.2W maximum
(Table
TRANSFORMER
59 of 87
1:2 step-up
1:2 step-up
1:2 step-up
1:2 step-up
1:2 step-up
16-3).
RETURN LOSS
21dB
NM
NM
NM
NM
Figure
P-P
broadband from 10Hz to
16-2. For the devices
*
Table
RT
2.5
2.5
6.2
**
0
0
(Ω)
16-4. The