DS26334G(2005) 查看數據表（PDF） - Dallas Semiconductor -> Maxim Integrated

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DS26334G
(Rev.:2005)

3.3V, 16-Channel, E1/T1/J1 Short- and Long-Haul Line Interface Unit

Dallas Semiconductor -> Maxim Integrated 

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 TEBGA

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 100W T1 twisted pair,

110W J1 twisted pair, 120W E1 twisted pair, and 75W 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 ETSI CTR12/13 ITU G.736,

G.742, G.823, and AT&T PUB62411 specifications.

The DS26334 detects and generates AIS in accordance with T1.231, G.775, and ETSI 300233. Loss of signal is

detected in accordance with T1.231, G.775, and ETSI 300233. 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 has the option to select internal impedance matching to

75W, 100W, 110W, or 120W with the use of a single external resistor. 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.

The DS26334 drives the E1 or T1 line from the TTIP and TRING pins by a 1:2 coupling transformer. The DS26334

supports the use of either a 1:1 or a 1:2 transformer on the receive side through the receiver turns ratio (RTR) bit.

For long-haul applications, a 1:1 transformer is preferred. Receive internal impedance matching allows one

external resistance value to work for all T1/J1/E1 modes.

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