4x4 Crosspoint Switch EVM U s e r 's G u i d e User's Guide January 2004 HPL-D SLLU064A
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.
EVM IMPORTANT NOTICE Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not considered by TI to be fit for commercial use.
EVM WARNINGS AND RESTRICTIONS It is important to operate this EVM within the input voltage range of -0.7 V to 4 V and the output voltage range of -0.5 V to 4 V. Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions concerning the input range, please contact a TI field representative prior to connecting the input power.
Preface Read This First About This Manual This evaluation module (EVM) user’s guide describes the hardware, theory of operation, and use of the EVM for evaluating the high-speed performance and functionality of either the SN65LVDS125A or SN65LVDS250 4x4 crosspoint switches. How to Use This Manual Chapter 1 provides an overview of the functional configurations and signal paths. Typical hardware setup and results are discussed in Chapter 2.
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Contents Read This First ................................................................................................................iii About This Manual..................................................................................................... iii How to Use This Manual ........................................................................................... iii Related Documentation from Texas Instruments ....................................................... iii If You Need Assistance .
Tables Figure 3-6. Layer 4–Vcc01 Plane ..................................................................................3-6 Figure 3-7. Layer 5–GND Plane ....................................................................................3-6 Figure 3-8. Layer 6–GND/Signal Plane.........................................................................3-7 Tables Table 2-1 Crosspoint Function Table...........................................................................2-3 Table 3-2.
Chapter 1 1 Overview This chapter provides a high-level description of the 4x4 crosspoint switch EVM mounted with either a SN65LVDS125A, 4x4 1.5-Gbps or a SN65LVDS250, 4x4 2.5-Gbps crosspoint switch. Topic Page 1.1 Sample Functional Configurations 1-2 1.
1 Overview 1.1 Sample Functional Configurations The 4x4 crosspoint switch is a fully non-blocking switch that provides flexibility in switch configuration for the desired application. A sample of various functions for which the EVMs can be configured is shown in Figure 1-1.
1 Overview Figure 1-2 shows the 4x4 crosspoint switch EVM (part number SN65LVDS125A or SN65LVDS250). The EVM comes with either the SN65LVDS125A or SN65LVDS250 installed and a copy of the data sheet. The latest version of the data sheet is also available from www.ti.com. A/W # 6456526 A SN65LVDS125A SN65LVDS250 4X4 Crosspoint Switch EVM Figure 1-2.
1 Overview 1.2 Signal Paths The signal paths on this EVM (see Figure 1-3) include: ❏ Sixteen edge-launch SMA connectors (J1–J16) for high-speed data transmission ❏ Eight jumpers (W1– W8) for active switch logic control ❏ Four jumpers (W9–W12) for enabling and disabling the outputs ❏ Three banana jacks (J17, J18, J19) for power and ground connections. Banana jack J20 is used for non-LVDS type configurations.
Chapter 2 2 Setup and Required Equipment Both the SN65LVDS125A and the SN65LVDS250 LVDS driver output characteristics are compliant with the requirements of the TIA/EIA-644 standard. LVDS drivers nominally provide a 350-mV differential signal, with a 1.2-V offset from ground. These levels are attained when driving a 100-Ω differential line-termination test load. This requirement includes the effects of up to 32 standard receivers with their ground references offset up to ±1 V from that of the driver.
2 Setup and Required Equipment + 3.3V Power Supply #1 - + 1.2V Power Supply #2 - DATA, DATA Amplitude: 400 mV Offset: 0.0 V J15 J13 W11 U1 1 J19 VCC01 J17 VCC ` J14 VCC 2DE GND GND W12 J4 J12 J5 VCC 3D E GND J11 J10 J9 J8 J7 DATA, DATA Amplitude: 400 mV Offset: 0.0 V VCC W9 W10 GND W8 VCC S41 VCC S31 GND J6 W6 4DE GND W7 VCC S40 W5 GND DATA, DATA Amplitude: 400 mV Offset: 0.
2 Setup and Required Equipment Table 2-1 Crosspoint Function Table Output Channel 1 Control Input Pins Selected Output Channel 2 Control Input Pins Selected Output Channel 3 Control Input Pins Selected Output Channel 4 Control Input Pins Selected S10 0 0 1 1 S20 0 0 1 1 S30 0 0 1 1 S40 0 0 1 1 S11 0 1 0 1 1Y/1Z 1A/1B 2A/2B 3A/3B 4A/4B S21 0 1 0 1 2Y/2Z 1A/1B 2A/2B 3A/3B 4A/4B S31 0 1 0 1 3Y/3Z 1A/1B 2A/2B 3A/3B 4A/4B S41 0 1 0 1 4Y/4Z 1A/1B 2A/2B 3A/3B 4A/4B Apply inputs to the SMA connecto
2 Setup and Required Equipment 2.2 Observing an Output In order to minimize the parasitic capacitance in high-speed measurements (probe capacitance), the 4x4 crosspoint switch EVM provides an offset power plane (layer 5). This power plane allows the user to offset the device so that the common-mode output is compatible with the 50 ohms to ground termination within the scope. Terminating the EVM within the scope eliminates any bandwidth limitations introduced by a probe.
2 Setup and Required Equipment Figure 2-3. Typical Test Results.
2 Setup and Required Equipment 2-6
EVM Construction Chapter 3 3 EVM Construction This chapter presents the schematics, board layouts, fabrication information, and the bill of materials. Topic Page 3.1 Schematic 3-2 3.2 Board Layout Patterns 3-3 3.3 PCB Fabrication Requirements and Stack Up 3-8 3.
SN65LVDS125A or SN65LVDS250 U1 3.1 Schematic Figure 3-1.
3 EVM Construction 3.2 Board Layout Patterns A/W # 6456526 SN65LVDS125A SN65LVDS250 4X4 Crosspoint Switch EVM Figure 3-2.
Figure 3-3.
3 EVM Construction Figure 3-4. GND Plane Figure 3-5.
Figure 3-6. Layer 4–Vcc01 Plane Figure 3-7.
3 EVM Construction Figure 3-8.
3.3 PCB Fabrication Requirements and Stack Up Notes: 1. PWB TO BE FABRICATED TO MEET OR EXCEED IPC-6012, CLASS 3 STANDARDS AND WORKMANSHIP SHALL CONFORM TO IPC-A-600, CLASS 3 CURRENT REVISIONS 2. BOARD MATERIAL AND CONSTRUCTION TO BE UL APPROVED AND MARKED ON THE FINISHED BOARD. 3. LAMINATE MATERIAL:COPPER-CLAD NELCO N4000-13 (DO NOT USE -13SI) 4. COPPER WEIGHT: 1oz FINISHED 5. FINISHED THICKNESS: 0.062" +/- 0.010" 6. MIN PLATING THICKNESS IN THROUGH HOLES: .001" 7. SMOBC / HASL 8.
3 EVM Construction 3.4 Bill of Materials Table 3-2. Bill of Materials for SN65LVDS125A / SN65LVDS250 EVM Item 6456526-1 Qty 6456526-2 Qty 6456526-3 Qty Description Pattern Reference Designator 1 9 9 9 0.001 µF 402 C2, C3, C4, C5, C6, C7, C8, C9, C10 2 2 2 2 0.01 µF 603 C13, C18 3 1 1 1 0.1 µF 603 C21 4 2 2 2 0.
