DS21Q55 Maxim Integrated Products, DS21Q55 Datasheet - Page 151

• Manufacturer Part Number: DS21Q55
• Description: IC TXRX QUAD T1/E1/J1 SCT 256BGA
• Manufacturer: Maxim Integrated Products

Specifications of DS21Q55

• Function: Transceiver
• Interface: E1, J1, T1
• Number Of Circuits: 4
• Voltage - Supply: 3.14 V ~ 3.47 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 256-BGA
• Includes: BERT Generator and Detector, Dual HDLC Controllers
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power (watts): -

22.7 LIU Control Registers
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
Bit 0/Transmit Power-Down (TPD)
Bit 1/Disable Jitter Attenuator (DJA)
Bit 2/Jitter Attenuator Buffer Depth Select (JABDS)
Bit 3/Jitter Attenuator Select (JAS)
Bit 4/Receive Equalizer Gain Limit (EGL). This bit controls the sensitivity of the receive equalizer.
Bits 5 to 7/Line Build-Out Select (L0 to L2). When using the internal termination, the user needs only to select
000 for 75Ω operation or 001 for 120Ω operation below. This selects the proper voltage levels for 75Ω or 120Ω
operation. Using TT0 and TT1 of the LICR4 register, the user can then select the proper internal source
termination. Line build-outs 100 and 101 are for backwards compatibility with older products only.
E1 Mode
*TT0 and TT1 of LIC4 register must be set to 0 in this configuration.
N.M = not meaningful
L2
0
0
1
1
L1
0 = powers down the transmitter and tri-states the TTIP and TRING pins
1 = normal transmitter operation
0 = jitter attenuator enabled
1 = jitter attenuator disabled
0 = 128 bits
1 = 32 bits (use for delay-sensitive applications)
0 = place the jitter attenuator on the receive side
1 = place the jitter attenuator on the transmit side
T1 Mode
0 = -36dB (long haul)
1 = -15dB (limited long haul)
E1 Mode
0 = -10dB (short haul)
1 = -43dB (long haul)
0
0
0
0
L2
L0
7
0
0
1
0
1
75Ω normal
120Ω normal
75Ω with high return loss
120Ω with high return loss
L1
LIC1
Line Interface Control 1
78h
6
0
Application
L0
5
0
*
EGL
*
4
0
151 of 237
JAS
0
3
N (1)
1:2
1:2
1:2
1:2
JABDS
2
0
Return Loss
N.M.
N.M.
21dB
21dB
DJA
1
0
Rt (1)
11.6
(Ω)
6.2
TPD
0
0
0
0