DS21552L+ Maxim Integrated Products, DS21552L+ Datasheet - Page 93

• Manufacturer Part Number: DS21552L+
• Description: IC TXRX T1 1-CHIP 5V 100-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS21552L+

• Function: Single-Chip Transceiver
• Interface: E1, HDLC, J1, T1
• Number Of Circuits: 1
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Includes: DSX-1 and CSU Line Build-Out Generator, HDLC Controller, In-Band Loop Code Generator and Detector
• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 64 Kbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 75 mA (Typ)
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Ic Interface Type: Parallel, Serial
• Supply Voltage Range: 4.75V To 5.25V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 100
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

16.5 RECEIVE MONITOR MODE
When connecting to a monitor port a large resistive loss is incurred due to the voltage divider between the
T1 line termination resistors (Rt) and the monitor port isolation resistors (Rm) as shown below. The Rm
resistors are typically 470 ohm. This, along with the 100 ohm termination (Rt), produces 20dB of loss.
The receiver of the DS21352/552 can provide gain to overcome the resistive loss of a monitor connection.
This is a purely resistive loss/gain and should not be confused with the cable loss characteristics of a T1
transmission line. Via the TEST2 register as shown in the table below, the receiver can be programmed
to provide both 12dB and 20dB of gain.
Figure 16-8 TYPICAL MONITOR PORT APPLICATION
Table 16-5 RECEIVE MONITOR MODE GAIN
T1 LINE
TEST2 (Address = 09 Hex) Register Value
Rm
72 Hex
70 Hex
MONITOR
PORT JACK
Rm
PRIMARY
T1 TERMINATING
DEVICE
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X
F
M
R
SECONDARY T1
TERMINATING
DEVICE
Gain
12dB
20dB
Rt
DS21X52