DS91M040EVK/NOPB

DS91M040 125 MHz Quad M-LVDS Transceiver Evaluation Kit USER MANUAL Part Number: DS91M040EVK NOPB For the latest documents concerning these products and evaluation kit, visit lvds.national.com. Schematics and gerber files are also available at lvds.national.com April 14, 2008 Rev. 1.0 1 © 2008, National Semiconductor Corp. Overview The purpose of this document is to familiarize you with the DS91M040 evaluation board, suggest the test setup procedures and instrumentation, and to guide you through some typical measurements that will demonstrate the performance of the device. The primary function of the board is to assist system designers in development and analysis of M-LVDS clock distribution networks in ATCA backplanes. The board also enables the user to examine performance and all functions of the DS91M040 as a standalone device or in a point-to-point configuration. The DS91M040 is a high-speed quad M-LVDS differential transceiver designed for multipoint applications with multiple drivers or receivers. The device conforms to TIA/EIA-899 standard. It utilizes M-LVDS technology for low power, high-speed and superior noise immunity. Description R0 D0 R1 D1 R2 D2 R3 D3 R0 D0 R1 D1 R2 D2 R3 D3 Figure 1 below represents the top layer drawing of the board with the silkscreen annotations. It is a 4 x 3 inch 10 layer printed circuit board (PCB) that features two DS91M040 (U1-U2) devices. MDE FSEN2 MDE FSEN2 FSEN1 DE 2 © 2008, National Semiconductor Corp. FSEN1 RE* April 14, 2008 Rev. 1.0 DE RE* Figure 1 - DS91M040EVK Top View Drawing Each device (U1 or U2) has four channels. The three M-LVDS channels of each device directly connect to the first two rows of J4, which is an ADF (Advanced Differential Fabric) connector. When J4 is inserted into any ATCA backplane slot (location J20/P20 for those of you familiar with ATCA backplanes), the M-LVDS I/O pins of each device electrically connect to one of the clock busses (there are six clock busses in an ATCA backplane – See Figure 2). The remaining M-LVDS channel of each device connects to the SMA connectors for device standalone evaluation or evaluation in point-to-point links. Table 1 provides M-LVDS I/O pin to J4 pin (and stub length) or SMA connector mapping and LVCMOS pins to J2 pin mapping. Device U1 U1 U1 U1 U2 U2 U2 U2 M-LVDS Pins A0 B0 A1 B1 A2 B2 A3 B3 A0 B0 A1 B1 A2 B2 A3 B3 J4 Pins / SMA Connector SMA1 SMA2 B1 A1 D1 C1 F1 E1 G1 H1 E2 F2 G2 H2 SMA3 SMA4 Stub Length NA 1.50” 1.00” 0.50” 0.50” 1.00” 1.50” NA LVCMOS Pins R0 D0 R1 D1 R2 D2 R3 D3 R0 D0 R1 D1 R2 D2 R3 D3 J2 Pins 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 Table 1 - U1 and U2 Pin to Connector Pin Mapping J1 provides easy connection to U1 control pins. Refer to the DS91M040 datasheet for the device pin descriptions. J3 provides easy connection to U2 control pins. Refer to the DS91M040 datasheet for the device pin descriptions. J5 and J6 are power and ground connections. April 14, 2008 Rev. 1.0 3 © 2008, National Semiconductor Corp. DS91M040 Evaluation in an ATCA Backplane The following is a recommended procedure for building an evaluation M-LVDS clock distribution network with DS91M040EVK evaluation boards. The assumption is that the user already has an ATCA backplane. Figure 2 depicts configuration of a generic M-LVDS clock network in an ATCA backplane. 1. Use two or more DS91M040 evaluation boards and install them at backplane location J20/P20, in the desired slots. 2. Apply the power to the boards (3.3V typical) between J5 and J6 banana plug receptacles, observe the value of ICC, and compare it with the expected value (refer to the datasheet) to ensure that the devices are functional. 3. Select the board you want to configure as a clock driver/distributor. This is accomplished by setting DE and RE* pins to VDD (J1 or J3). Set MDE pin to VDD. Connect a clock source to one of the driver inputs (J2). 4. Configure the remaining boards as clock receivers. This is accomplished by setting DE and RE* pins to GND (J1 or J3). Set MDE pin to VDD. Set the receiver to either M-LVDS Type 1 (FSEN pins set to GND) or Type 2 (FSEN pins set to VDD). 5. Observe clock waveforms by either connecting receiver LVCMOS output pins (J2) directly to an oscilloscope or by probing receiver M-LVDS input pins with a differential probe. Figure 2 - M-LVDS Clock Distribution Network in an ATCA Backplane April 14, 2008 Rev. 1.0 4 © 2008, National Semiconductor Corp. The block diagram of Figure 2 details a clock distribution network in an ATCA backplane. The clock busses have 130-ohm differential impedance and are doubly terminated with 80 ohms at either end of the backplane. The parallel combination of 80-ohm resistors means that the MLVDS devices will be driving a 40-ohm load termination. The maximum stub length from the backplane is defined in the ATCA standard as 1 inch or 2.54 cm. Figure 3 shows a picture of a 14-slot ATCA backplane fully populated with DS91M040 evaluation boards. Figure 3 - DS91M040 Evaluation Boards in an ATCA Backplane April 14, 2008 Rev. 1.0 5 © 2008, National Semiconductor Corp. Figure 4 shows 19.44 MHz clock waveforms obtained with a differential probe, Tektronix P6330, on the M-LVDS input pins of the device on a receiver board in slot #8. The14-slot backplane was fully populated. The clock driver/distributor board was in slot #7. Figure 4 - 19.44 MHz Clock Waveforms Show Stub Length Effects on Signal Integrity April 14, 2008 Rev. 1.0 6 © 2008, National Semiconductor Corp. DS91M040 Evaluation in a Point-to-Point Link The following is a recommended procedure for building an evaluation M-LVDS point-point network with DS91M040 evaluation boards. Figure 5 depicts a typical setup and instrumentation used for evaluation of a point-to-point link. 1. Use a single DS91M040 evaluation board. 2. Apply the power to the board (3.3 V typical) between J5 and J6 banana plug receptacles, observe the value of ICC, and compare it with the expected value (refer to the datasheet) to ensure that the devices are functional. 3. Configure U1 as a driver. This is accomplished by setting DE and RE* pins to VDD (J1). Connect a signal source to the driver inputs (J2, pin 3). 4. Configure U2 as a receiver. This is accomplished by setting DE and RE* pins to GND (J3). 5. Select a differential interconnect with balanced 100-ohm differential impedance (i.e. UTP cable) and connect the M-LVDS pins of both devices through SMA connectors (SMA1 and SMA2 for U1 driver outputs; SMA3 and SMA4 for U2 receiver inputs ;). You may want to consider developing / obtaining an SMA to RJ45 adapter board for easy interface from SMA connectors to twisted pair cables. See the following link: http://www.national.com/appinfo/lvds/sma2rj45evk.html. 6. Terminate the interconnect with a matching resistor on the inputs of the U2 receiver (R2). 7. Observe waveforms by either connecting the receiver LVCMOS output pin (J2, pin 29) directly to an oscilloscope or by probing receiver M-LVDS input pins with a differential probe. Figure 5 - M-LVDS Point-to-Point Link with DS91M040 Boards and UTP Cable April 14, 2008 Rev. 1.0 7 © 2008, National Semiconductor Corp. Figure 6 shows eye diagrams acquired at the output of the DS91M040 driver loaded with a 100-ohm resistor and after 50 m CAT5e cable terminated with a 100-ohm resistor. The generator connected to the driver input simulated a 100 Mbps PRBS-7 NRZ. Figure 6 - Eye Diagram Before and After 50m of CAT5e April 14, 2008 Rev. 1.0 8 © 2008, National Semiconductor Corp. IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps DSP dsp.ti.com Energy and Lighting www.ti.com/energy Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial Interface interface.ti.com Medical www.ti.com/medical Logic logic.ti.com Security www.ti.com/security Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap Wireless Connectivity www.ti.com/wirelessconnectivity TI E2E Community Home Page e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2012, Texas Instruments Incorporated