DS26334GNA3+ Maxim Integrated Products, DS26334GNA3+ Datasheet - Page 7

• Manufacturer Part Number: DS26334GNA3+
• Description: IC LIU E1/T1/J1 3.3V 256-CSBGA
• Manufacturer: Maxim Integrated Products
• Type: Line Interface Units (LIUs)r

Specifications of DS26334GNA3+

• Number Of Drivers/receivers: 16/16
• Protocol: IEEE 1149.1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Mounting Type: Surface Mount
• Package / Case: 256-CSBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS26334 3.3V, 16-Channel, E1/T1/J1 Short/Long-Haul Line Interface Unit
2 DETAILED DESCRIPTION
The DS26334 is a single-chip, 16-channel, long-haul and short-haul line interface unit for T1 (1.544Mbps) and E1
(2.048Mbps) applications. Sixteen independent receivers and transmitters are provided in a single TE-CSBGA
package. The LIUs can be individually selected for T1, J1, or E1 operation. The LIU requires a single master
reference clock. This clock can be either 1.544MHz or 2.048MHz or multiples thereof, and either frequency can be
internally adapted for T1, J1, or E1 mode. Internal impedance matching provided for both transmit and receive
paths reduces external component count. The transmit waveforms are compliant to G.703 and T1.102
specification. The DS26324 provides software-selectable internal transmit termination for 100Ω T1 twisted pair,
110Ω J1 twisted pair, 120Ω E1 twisted pair, and 75Ω E1 coaxial applications. The transmitters have fast high-
impedance capability and can be individually powered down.
The receivers can function with up to a receive signal attenuation of 36dB for T1 mode, or 43dB for E1 mode. A
monitor gain setting also can be enabled to provide 14dB, 20dB, 26dB, and 32dB of resistive gain. The DS26334
can be configured as a 14-channel LIU with Channel 1 and 9 used for nonintrusive monitoring in accordance with
G.772. The receivers and transmitters can be programmed into single or dual-rail mode. AMI or HDB3/B8ZS
encoding and decoding is selectable in single-rail mode. A 128-bit crystal-less on-board jitter attenuator for each
LIU can be placed in receive or transmit directions. The jitter attenuator meets the ETS CTR12/13 ITU-T G.736,
G.742, G.823, and AT&T Pub 62411 specifications.
The DS26334 detects and generates AIS in accordance with T1.231, G.775, and ETS 300 233. Loss of signal is
detected in accordance with T1.231, G.775, and ETS 300 233. The DS26334 can perform digital, analog, remote,
and dual loopbacks on individual LIUs. JTAG boundary scan is provided for the digital pins.
The DS26334 can be configured using 8-bit multiplexed or nonmultiplexed Intel or Motorola ports. A 4-pin serial
port selection is also available for configuration and monitoring of the device.
The analog AMI/HDB3 waveform of the E1 line or the AMI/B8ZS waveform of the T1 line is transformer coupled
into the RTIP and RRING pins of the DS26334. The user can terminate the receive line using only internal
termination that requires no external resistors. Or, the user has the option to use partially internal impedance
matching using a common 120Ω external resistor for E1, T1, and J1, and matching the line impedance internally to
obtain 75Ω, 100Ω, 110Ω, or 120Ω termination values. Note that fully internal impedance match requires a 1:1
transformer on the receive line. Partially internal impedance matching supports either a 1:1 or a 1:2 transformer on
the receive line. If a 1:2 transformer is used, the external termination resistor should be 30Ω. For long-haul
applications, a 1:1 transformer on the receive line is preferred. The DS26334 drives the E1 or T1 line from the TTIP
and TRING pins by a 1:2 coupling transformer.
The device recovers clock and data from the analog signal and passes it through a selectable jitter attenuator
outputting the received line clock at RCLK and data at RPOS and RNEG.
The DS26334 receivers can recover data and clock for up to 36dB of attenuation of the transmitted signals in T1
mode and 43dB for E1 mode. Receiver 1 can monitor the performance of receivers 2 to 8 or transmitters 2 to 8.
Receiver 9 can monitor the performance of receivers 10 to 16 or transmitters 10 to 16.
The DS26334 contains 16 identical transmitters. Digital transmit data is input at TPOS/TNEG with reference to
TCLK. The data at these pins can be single-rail or dual-rail. This data is processed by waveshaping circuitry and
the line driver to output at TTIP and TRING in accordance with ANSI T1.102 for T1/J1 or G.703 for E1 mask.
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