DS3100 Datasheet, PDF (62/226 Pages) Maxim Integrated Products – Stratum 3/3E Timing Card IC

DS3100 Stratum 3/3E Timing Card IC
7.10.4 Line Interface Unit
The line interface unit (LIU) contains the receiver, which recovers clock and data from the inbound cable, and the
transmitter, which wave-shapes and drives the signal onto the outbound cable. These sections are controlled by
the line interface control registers, BLCR1 through BLCR4.
The receiver has a usable receive sensitivity of 0dB to -43dB for E1 and 0dB to -36dB for DS1, which allows the
device to operate on 0.63mm (22AWG) cables up to 2.5 km (E1) and 6000 feet (DS1) in length. The transmitter line
driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or short-haul (DSX-1) lines for DS1.
The receiver and transmitter can switch among the supported synchronization signal types without changing
external components. Figure 7-10 shows the minimum set of external components required. Both the receiver and
the transmitter can adjust their termination impedance to provide high return loss characteristics for 75Ω, 100Ω,
110Ω, and 120Ω lines. Other components may be added to this configuration in order to meet safety and network
protection requirements, if required.
Figure 7-10. BITS Transceiver External Components
Internal Receiver Termination Enabled
1uF
560 pF
TTIP
TTIP
VDD
3.3V
0.1uF
1uF
10uF
Power
VDD
Plane
0.1uF
1uF
10uF
TRING _VDD
1.8V
Power
2:1
TRING
0.1uF
1uF
10uF
Plane
RTIP
VSS
VSS
RRING ^VSS
1:1
Note: The 1uF capacitor is mandatory for 2048kHz mode and optional for DS1 and E1 modes.
Ground
Plane
Internal Receiver Termination Disabled
1uF
560 pF
2:1
TTIP
TTIP
TRING
TRING
VDD
VDD
VDD
0.1uF
1uF
10uF
3.3V
Power
Plane
0.1uF
1uF
10uF
1.8V
Power
0.1uF
1uF
10uF
Plane
60.4Ω
(1%)
60.4Ω
(1%)
1:1
0.1 uF
RTIP ^VSS
VSS
RRING _VSS
Note: The 1uF capacitor is mandatory for 2048kHz mode and optional for DS1 and E1 modes.
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Ground
Plane