LXT331 PM4344/6344 AN058 PM4344 PM6344 TG29-1205NX LEN00 LEN10 LEN20 LEN01

with PMC PM4344/6344 Quad Framers Application Note January 2001 Order Number: 249166-001 As of January 15, 2001, this document

Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers Application Note January 2001 Order Number: 249166-001 As of January 15, 2001, this document replaces the Level One document known as AN058 AN058. Information in this document is provided in connection with Intel® products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Intel's Terms and Conditions of Sale for such products, Intel assumes no liability whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not intended for use in medical, life saving, or life sustaining applications. Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. The Intel LXT331 LXT331 Dual Transceivers may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request. Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order. Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800-548-4725 or by visiting Intel's website at http://www.intel.com. Copyright © Intel Corporation, 2001 *Third-party brands and names are the property of their respective owners. Application Note Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers Contents 1.0 General Description . 5 1.1 1.2 1.3 Solution Benefits . 5 Reference Layout . 5 References . 8 1 2 E1 75 Coax Quad Port Layout. 7 Total Component Area . 8 Figures Application Note 3 Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers 1.0 General Description The LXT331 LXT331 dual T1/E1 LIU interfaces with PMC-Sierra PM4344/6344 PM4344/6344 quad framers, providing a very compact and cost-effective four-port solution. This Application Note describes an appropriate configuration of both the LXT331 LXT331 and the PMC quad framers. The LXT331 LXT331 is a high-performance dual T1/E1 line interface unit providing a rich set of features including: data recovery, stand-alone hardware mode or serial host mode, analog loopback and driver performance monitoring. It also features a constant low impedance transmit driver for optimum transmit return loss, and switchable T1/E1 operation without component changes. The PMC-Sierra PM4344 PM4344 (T1 framer) and PM6344 PM6344 (E1 framer) are quad port framers suitable for use in most T1/E1 applications with a minimum of external circuitry. Relevant features include: clock recovery, alarm condition detection (such as loss of signal, loss of framing, and AIS) digital jitter attenuator (configurable for receive or transmit side), HDLC message termination and performance monitoring. The design shown in Figure 1 uses an octal transformer from HALO Electronics that interfaces directly with the LXT331 LXT331. As the first surface-mount octal T1/E1 transformer in the industry, this compact device supports all four channels in a quad port design (transmit and receive) and can be used both for T1 and E1 operation. 1.1 Solution Benefits · T1/E1 operation with single board design - Single transformer and LIU for 75/100/120 systems; pin-compatible framers · No high frequency reference clock required · Minimal board real estate · Sophisticated driver monitoring - Secondary short detection - Driver performance monitoring - Tristate capability for 1+1 protection applications - Meets BABT 50 mA driver short circuit current limit by design 1.2 Reference Layout Figure 1 shows a layout diagram of a four port solution that includes two dual transceivers and one quad framer for an E1 75 coaxial cable interface. For a T1 solution, the framer would be the PM4344 PM4344, that is pin compatible with the PM6344 PM6344 EQUAD. The LXT331 LXT331 is T1/E1 switchable. For T1 operation, choose the appropriate line length settings LEN, and adjust the receive termination to 100. Refer to the LXT331 LXT331 data sheet for additional details. The octal transformer from HALO can be used for both T1 and E1 applications. Application Note 5 Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers At the network side, the transmit and receive lines interface with the LXT331 LXT331 LIU through the TG29-1205NX TG29-1205NX octal transformer. The transmit transformer has a 1:2 turns ratio. The receive transformer is a 1:2 center-tap used at a 1:1 turns ratio. The receive side 37.5 resistors provide adequate termination and low common mode impedance for an E1 coaxial cable interface. On the transmit side, the 9.1 series resistors between the transformer and the LIU provide excellent transmit return loss (18 dB typical). This provides a good margin for compliance with the latest ETSI standards such as ETS 300 166. Furthermore, the resistors also ensure maximum protection against excessive surge currents and allow compensation for amplitude loss in external protection networks. In Figure 1, the LXT331 LXT331 is configured in hardware mode. This mode does not require the allocation of any microprocessor resources. However, if microprocessor control is preferred, the device can be configured for host mode to allow control through a simple, three-wire serial interface. In Figure 1, the line length inputs are set to LEN=000 (E1 75 operation). If TCLK is provided, the MCLK input can be grounded. The PM6344 PM6344 EQUAD is configured for dual rail input (RDPx, RDNx) and Return-to-Zero (RZ) mode. The clock recovery block inside the framer extracts the clock and the analog LOS information from the RZ pulses provided by the LXT331 LXT331, using a digital PLL. Digital loss of signal detection, HDB3 decoding and bipolar violation detection are also included in this device. 6 Application Note Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers Figure 1. E1 75 Coax Quad Port Layout +5 V 68 µF BTPCM/BTDP[4.1] BTSIG/BTDN[4.1] BTCLK[4.1] BTFP[4.1] TCLKI[4.1] PM6344 PM6344 MCLK DPM0 DFM0 TCLK0 TPOS0 TNEG0 PMRK0 NMRK0 TCLKO[1] TDP[1] TDN[1] RDP[1] RDN[1] RCLKI[1] TCLKO[2] TDP[2] TDN[2] RDP[2] RDN[2] RCLKI[2] TRING0 GND 9.1 37.5 37.5 1 K 5 V TVS (Semtech SMCJ5.0AC) RTIP1 +5V 0.1 µF 0.1 µF 37.5 0.1 µF 1 K RRING1 TTIP1 TRING1 470 pF 9.1 MTIP1 MRING1 1:2 +5 V 68 µF RDLSIG/RDLINT[4.1] Transmit data link signal/interrupt TDLSIG/TDLINT[4.1] HALO TG29-1205NX TG29-1205NX µP I/F BRCLK/MRCLK BRFPI/MRFPI TCLKO[3] TDP[3] TDN[3] RDP[3] RDN[3] RCLKI[3] TCLKO[4] TDP[4] TDN[4] RDP[4] RDN[4] RCLKI[4] MRD MENB XCLK RSTB ALE WRB RDB CSB INTB A[9.0] D[7.0] TVCC0 LEN00 LEN00 LEN10 LEN10 LEN20 LEN20 TAOS0 ALOOP0 TGND0 MCLK DPM0 DFM0 TCLK0 TPOS0 TNEG0 PMRK0 NMRK0 TRING0 LXT331 LXT331 5V GND 9.1 5 V TVS (Semtech SMCJ5.0AC) 0.1 µF 1 K +5V 0.1 µF 0.1 µF 37.5 2CT:1 2CT:1 37.5 1 K RRING1 TRING1 37.5 37.5 1 K RTIP1 TTIP1 1:2 470 pF 0.1 µF 1 K RRING0 VCC 9.1 Line Protection (see below) RTIP0 TCLK1 TPOS1 TNEG1 PMRK1 NMRK1 DPM1 DFM1 TRSTE MTIP0 MRING0 TTIP0 LEN01 LEN01 LEN11 LEN11 LEN21 LEN21 TAOS1 ALOOP1 TGND1 TVCC1 Crystal ref. clock Reset signal TDLCLK/TDLURD[4.1] PLD[3.0] Serial mux I/F 68 µF RDLCLK/RDLEOM[4.1] PLA[5.0] Ext. synchronous backplane timing sources 2CT:1 9.1 Line Protection (see below) +5 V Receive data link signal/interrupt 2CT:1 37.5 1 K DPM1 DFM1 TRSTE BRFPO[4.1] RCLKO[4.1] RFP[4.1] RRING0 VCC 1:2 470 pF 0.1 µF 1 K LXT331 LXT331 9.1 Line Protection (see below) RTIP0 TCLK1 TPOS1 TNEG1 PMRK1 NMRK1 BRPCM/BRDP[4.1] BRSIG/BRDN[4.1] MTIP0 MRING0 TTIP0 LEN01 LEN01 LEN11 LEN11 LEN21 LEN21 TAOS1 ALOOP1 TGND1 TVCC1 Receive PCM backplane I/F TVCC0 PHD[3.0] PHA[4.0] Transmit PCM backplane I/F LEN00 LEN00 LEN10 LEN10 LEN20 LEN20 TAOS0 ALOOP0 TGND0 Power Line Protection (see below) MTIP1 MRING1 9.1 470 pF 9.1 1:2 +5 V 68 µF Line Protection Circuit D1 TTIP D2 D1 - D4: Motorola MBR0540T1 MBR0540T1 or International Rectifier 11DQ04 11DQ04 or 10BQ060 10BQ060 D3 TRING D4 5V Application Note 7 Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers In normal operation, the PM6344 PM6344 Digital Jitter Attenuator (DJAT) is placed in the transmit direction. The elastic store in the receive side provides adaptation between the recovered line clock and the backplane clock (BRCLK). When the backplane timing is derived from the receive line data (i.e. the RCLKOx output is used) the elastic store can be combined with the DJAT digital PLL to provide receive jitter attenuation. This is accomplished by locking the elastic store output clock to the de-jittered recovered clock. The framer backplane signals are also represented in Figure 1. These signals would be further processed in a real application. Figure 2 shows an approximate measurement of area for the quad port design described above. Real package sizes were used to make this measurement. A total of only 4.15 sq inches is required for the complete solution. The LXT331 LXT331 is also available in a very compact QFP package. Figure 2. Total Component Area 0.68 in. PM6344 PM6344 PM6344 PM6344 0.91 in. LXT331 LXT331 0.52 in. TG29-1205NX TG29-1205NX TG29-1205NX TG29-1205NX 0.625 in. 0.52 in. 1.7 in Total Area: 4.15 sq inches References · · · · 8 2.44 in LXT331 LXT331 0.52 in. 1.3 LXT331 LXT331 LXT331 LXT331, Dual T1/E1 Line Interface Unit Data Sheet, Intel Communication ICs Data Book 1996, Intel PM6344 PM6344, Quadruple E1 Framer Data Sheet, PMC-Sierra Inc. PM4344 PM4344, Quadruple T1 Framer Data Sheet, PMC-Sierra Inc. Application Note Intel® LXT331 LXT331 Dual Transceivers with PMC PM4344/6344 PM4344/6344 Quad Framers · PM6344 PM6344 EQUAD, Answers to Frequently Asked Questions Regarding the EQUAD, PMCSierra Inc. · PM4344 PM4344 TQUAD, Answers to Frequently Asked Questions Regarding the TQUAD, PMCSierra Inc. · TG29-1205NX TG29-1205NX Transformer Data Sheet, Halo Electronics Inc. Application Note 9