Video lectures from the iCS group @ IIT Madras

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pcb_testing [2014/09/10 19:28] (current)
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 +====== Testing equipment ======
 +The testing lab contains a number of high performance and expensive equipment. Acquaint yourselves with the equipment by reading the manuals to get the best out of them. Here is a [[testlabequipments|list of instruments in the testing lab]]. ​
 +
 +^ Purpose ^ Document ^
 +|Brief tutorial on data capture using 1682AD logic analyzer|{{1682ad_data_capture.pdf}}|
 +|Histogram based INL/DNL measurements (Appln note from Maxim)|{{inl_dnl.pdf}}{{inl_dnl.m}}|
 +|Tutorial for ORCAD|{{ORCAD_tutorial.pdf}}|
 +|LabView tutorial|{{labview_tutorial.ppt}}|
 +
 +
 +====== OrCAD Tips ======
 +
 +===== Drawing Schematics =====
 +  * Use seperate symbols for electrolytic capacitors and surface mount capacitors.
 +  * While using electrolytic capacitors, pay attention to the positive and negative terminals. Terminal 1 in schematic should be connected to higher voltage and terminal 2 to lower voltage.
 +  * Maximum value of non-polar surface mount cap is 1uF (@ modi electronics,​ ritchie street).
 +  * Use seperate symbols for thru-hole resistors and surface mount resistors.
 +  * There is a pushbutton in Orcad to generate 'Bill Of Materials'​. This will aid in determining which all components to purchase.
 +
 +
 +===== Printing Schematics =====
 +  * To save schematics as PDF, first you will need to install PDF995 ( a free software).
 +  * Change print setting to '​Landscape',​ and output as '​PDF995'​.
 +
 +===== Placement =====
 +  * First switch off '​Online DRC'. Else you will be unable to reorder the footprints.
 +
 +===== Routing =====
 +  * Before starting to route, we must fix the width of each net. Tools-->​Net-->​Select from Spreadsheet. Here we can fix the min,typ and max width of each net. For GNDA and VDDA it is 12,50,100, and for other nets 12,25,50.
 +  * To start routing click '​Add/​Edit Route Mode' button in the task bar.
 +
 +===== Submission =====
 +  * .MAX file contains the layout and .DSN file contains the schematic.
 +  * Only the .MAX file needs to be submitted for fabrication. No need to generate the GERBER files.
 +  * The shape of the PCB need not necessarily be a square/​rectangle. ​
 +
 +===== PCB Fabrication / Component purchase =====
 +
 +
 +====Fabrication==== ​
 +  * Printed Circuit Services(Zeta),​ I-1, Dr.V.S.I Estate, Near NIFT, Thiruvanmiyur. **Ph: 22541641, 42150860**, **Email: plot@zetapcs.com**
 +  * Tessolve
 +
 +====Technical information about the PCB==== ​
 +  * Type of material used : FR-4(an abbreviation for Flame Retardant 4, a glass reinforced epoxy laminate used for making printed circuit boards.)
 +  * Dielectric Constant: Varies according to the frequency applied and depends on the vendor.(A value of 4-4.5 seems to be appropriate for high frequency designs >1GHz)
 +  * Standard thickness of board: 1.6 mm
 +  * Thickness of copper trace: 35 ยตm
 +
 +The above information can be used to determine the trace impedance.
 +
 +====Component Purchase==== ​
 +  * Modi Electronics,​ No 6, 1st floor, Ritchie Street. **Ph: 28414140**
 +  * Mercy Electronics,​ L.B Road, Adyar. **Ph: 24464481**
 +  * Mency Electronics,​ Tharamani Road, Velachery. **Ph: 22434773, 42082097**
 +  * Texonic, Ritchie Street. **Ph: 28410638**
 +  * Globe Tronics, Ritchie Street. (All kinds of male/female connectors, adapters etc.) **Ph. No: 42119262, 42149503**
 +  * SRICOM(Srinar Communications) (RF Cables, Connectors, and other accessories...) http://​www.sricomworld.in/;​ email : mtk@sricomworld.com\\ **Ph.No : +91 9841005125 (Mr. Ismail)**
 +
 +====Assembly==== ​
 +Sri International