Compaq M-LVDS manual Point-to-Point Parallel Terminated Simplex Transmission

Page 19

Typical Cable Test Configurations

2.1.2Point-to-Point Parallel Terminated Simplex Transmission

1)Connect a twisted-pair cable from P1 to P2.

2)Verify resistor R4 and R7 are installed.

3)Remove resistors R5 and R6. This properly terminates the transmission line at both ends.

4)Enable the driver by connecting the jumper on W2 between pin 1 and pin 2, or U1 pin 4 to VCC.

5)Enable the receiver by connecting the jumper on W1 between pin 2 and pin 3, or U1 pin 3 to GND.

Figure 2−2. Point-to-Point Parallel Terminated Simplex Transmission

VCC

Signal Source

with 50-

Output

50-

Cable

J2

TP2

 

 

Jumper

 

 

Input Signal

 

W2

 

 

4

9

 

 

 

5

R7

 

R6

 

P2

U1

 

100

100

R3

10

 

 

 

 

49.9

 

 

 

Twisted Pair Cable

 

 

 

 

 

 

 

50-

 

R2

 

 

50-

cable or

Cable

J1

 

12

453

2

 

 

 

R4

Active Voltage

 

 

 

U1

100

Probe into one

 

 

 

3

 

 

TP1

11

Channel of Scope

 

 

VCC

 

 

 

Terminated in

 

 

 

 

 

High Impedance

 

 

 

 

W1

 

 

 

 

Output Signal

 

 

 

 

Active Voltage

 

Jumper

 

 

 

 

 

 

 

 

 

 

Probe

 

 

 

 

P1

R5

100

 

2.1.3Two-Node Multipoint Transmission

1)Connect a twisted-pair cable between P1, P2, and P3.

2)Verify resistor R5 and R16 are installed.

3)Remove resistors R4, R6, R7, and R15. This properly terminates the transmission line at both ends.

4)Enabling the driver in a two-node multipoint configuration will be a slightly more challenging task. The user can either jumper enable a single driver and send all of the data on the bus through a single driver, or sync the driver enable to the data and send data from each driver. Enable a single driver by connecting the jumper on W4 between pin 1 and pin 2 which

connects U2 pin 3 to VCC, or by connecting the jumper on W2 between pin 1 and pin 2 which connects U1 pin 4 to VCC.

5)Enable the receivers by connecting the jumpers on W1 and W3 between pin 2 and pin 3, or U1 pin 3 to GND and U2 pin 2 to GND.

Test Setup

2-3

Image 19
Contents User’s Guide Important Notice EVM Important Notice EVM Warnings and Restrictions Preface How to Use This ManualPage Contents Tables FiguresTopic M-LVDS Evaluation Module−1. M-LVDS Devices Supported by the EVM OverviewLvds Standard TIA/EIA−899 Lvds EVM Kit Contents Point-to-Point ConfigurationsMultipoint Multidrop−7. Two-Node Multipoint Circuit EVM Operation With Separate Power Supplies Recommended Equipment PS1 PS2 PS3Test Setup −1. EVM Configuration Options Typical Cable Test ConfigurationsPoint-to-Point Simplex Transmission Two-Node Multipoint Transmission Point-to-Point Parallel Terminated Simplex Transmission−3. Two-Node Multipoint Transmission −4. Point-to-Point Parallel Simplex Typical Eye Pattern Data Test ResultsDriver Input Receiver #1 Output Receiver #2 Bill of Materials, Board Layout, and PCB Construction −1. M-LVDS EVM Bill of Materials Bill of MaterialsBoard Layout −1. Assembly DrawingÏïïïïïïïïïïïïï Ï Ìììììììììììììì Ì −5. Bottom Layer + 2 Z 374e * 2.9s h PCB ConstructionMicrostripstripline Mils −2. EVM Layer Stack UpThis Appendix contains the EVM schematic SchematicVCC