DS21Q50L Maxim Integrated Products, DS21Q50L Datasheet - Page 57

• Manufacturer Part Number: DS21Q50L
• Description: IC TRANSCEIVER 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: 100-LQFP
• Includes: AIS Alarms Detector and Generator, Loopback Functions, PRBS Generator / Detector, Remote Detector and Generator
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power (watts): -

16.2 Termination
The DS21Q50 is designed to be fully software-selectable for 75W and 120W termination without the need
to change any external resistors. The user can configure the DS21Q50 for 75W or 120W receive
termination by setting the IRTSEL (CCR5.4) bit. When using the internal termination feature, the
external termination resistance should be 120W (typically two 60W resistors). Setting IRTSEL = 1 causes
the DS21Q50 to internally apply parallel resistance to the external resistors in order to adjust the
termination to 75W. See
16.3 Receive Monitor Mode
When connecting to a monitor port, a large resistive loss is incurred due to the voltage divider between
the E1 line termination resistors (Rt) and the monitor port isolation resistors (Rm) as shown in
Figure
monitor connection. This is typically a purely resistive loss/gain and should not be confused with the
cable loss characteristics of an E1 transmission line. By setting the receive monitor mode register as
shown in
Figure 16-1. Typical Monitor Port Application
Table 16-1. Receive Monitor Mode Gain
(ADDRESS = 1Fh) REGISTER
16-1. The four receivers of the DS21Q50 can provide gain to overcome the resistive loss of a
MONITOR MODE
Table
VALUE
16-1, the receiver can be programmed to provide 30dB of gain.
70h
00h
E1 LINE
Rm
Figure 16-3
MONITOR
PORT JACK
for details.
Rm
PRIMARY
E1 TERMINATING
DEVICE
GAIN (dB)
57 of 87
30
0
X
F
M
R
SECONDARY
TERMINATING
DEVICE
Rt DS21Q50