DS2151QNB+ Maxim Integrated, DS2151QNB+ Datasheet - Page 41

• Manufacturer Part Number: DS2151QNB+
• Description: Network Controller & Processor ICs
• Manufacturer: Maxim Integrated

Specifications of DS2151QNB+

• Product: Framer
• Number Of Transceivers: 1
• Data Rate: 2.048 Mbps
• Supply Current (max): 65 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: PLCC-44
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 5 V
• Supply Voltage - Max: 5.25 V
• Supply Voltage - Min: 4.75 V
• Part # Aliases: 90-2151Q+NB0

13.2 Transmit Waveshaping and Line Driving
The DS2151Q uses a set of laser-trimmed delay lines along with a precision Digital-to-Analog Converter
(DAC) to create the waveforms that are transmitted onto the T1 line. The waveforms created by the
DS2151Q meet the latest ANSI, AT&T, and CCITT specifications. See
which waveform is to be generated by properly programming the L0 to L2 bits in the Line Interface
Control Register (LICR).
Table 13-2. LBO Select in LICR
Due to the nature of the design of the transmitter in the DS2151Q, very little jitter (less than 0.005UI
broadband from 10Hz to 100kHz) is added to the jitter present on TCLK. Also, the waveforms that they
create are independent of the duty cycle of TCLK. The transmitter in the DS2151Q couples to the T1
transmit twisted pair via a 1:1.15 or 1:1.36 step-up transformer as shown in
to create the proper waveforms, the transformer used must meet the specifications listed in
Table 13-3. Transformer Specifications
Turns Ratio
Primary Inductance
Leakage Inductance
Intertwining Capacitance
DC Resistance
L2
0
0
0
0
1
1
1
1
SPECIFICATION
L1
0
0
1
1
0
0
1
1
L0
0
1
0
1
0
1
0
1
LINE BUILD-OUT
0 to 133 feet/0dB
133 to 266 feet
266 to 399 feet
399 to 533 feet
533 to 655 feet
1:1 (receive) and 1:1.15 or 1:1.36 (transmit) ±5%
600µH minimum
1.0µH maximum
40pF maximum
1.2Ω maximum
-22.5dB
-7.5dB
-15dB
RECOMMENDED VALUE
41 of 60
APPLICATION
DSX-1/CSU
DSX-1
DSX-1
DSX-1
DSX-1
CSU
CSU
CSU
Figure
Figure
13-3. The user will select
13-1. For the devices
Table
13-3.
P-P