ECE 477 Digital Systems Senior Design Project Rev 2/12
Homework 4: Packaging Specifications and Design
Team Code Name: AWESILLOSCOPE Group No. 2
Team Member Completing This Homework: Jintao Zhang
E-mail Address of Team Member: zhang451 @ purdue.edu
Evaluation:
SCORE
/DESCRIPTION
10 /Excellent – among the best papers submitted for this assignment. Very few corrections needed for version submitted in Final Report.
9 /Very good – all requirements aptly met. Minor additions/corrections needed for version submitted in Final Report.
8 /Good – all requirements considered and addressed. Several noteworthy additions/corrections needed for version submitted in Final Report.
7 /Average – all requirements basically met, but some revisions in content should be made for the version submitted in the Final Report.
6 /Marginal – all requirements met at a nominal level. Significant revisions in content should be made for the version submitted in the Final Report.
* /Below the passing threshold – major revisions required to meet report requirements at a nominal level. Revise and resubmit.
* Resubmissions are due within one week of the date of return, and will be awarded a score of “6” provided all report requirements have been met at a nominal level.
Comments:
Comments from the grader will be inserted here.
1.0 Introduction
Our proposed project is a digital oscilloscope with playback function that provides almost any function of a typical oscilloscope, such as digital sampling; signal processing, auto-scale setting, cursor setting, reconstruction and visualization of signals. Additional features such as recording and replicating signals as a function generator.
Since we utilize VGA output for the video, it is not necessary to implement a graphic LCD/ display screen directly on the device. Also based on out selected parts and components necessary, the package would be rather compact and portable without extra effort.
2.0 Commercial Product Packaging
The commercial products we use to reference are Agilent 54621A a relatively classis oscilloscope, and an up-to-date commercial product, DSO nano v2.
The features in the Agilent product that we will implement in our design are the basic functions, such as trigger, auto/manual scaling, time/voltage measurement, and run/stop. From the DSO nano v2,
2.1 Product #1
Fig. 2.1 Agilent 54621A
The typical Oscilloscope we can see in every EE lab.
This device contains series of coupling, attenuating, and amplifier circuitry with a analog to digital converter, to perform a high rate sampling and reconstruction process. The Oscilloscope record the sampled points, trigger level, and time/voltage range into data-storage before display the signal, and let user to choose the range of display. It also supports auto/manual scaling function to properly display the signal.
The device also has a wide-range of measurement utilities. By analyzing the stored data, it can give a quick measure to the typical properties of the signal.
The user interface of the device is also friendly and easy to use. However, our design will utilize less pushbutton and place most of the control/measurements selections in an RPG-controlled display menu on VGA output.
In conclusion, the device has a relatively high sampling rate, user-friendly interface and can satisfied most functions for lab use. On the other hand, however, the device is too heavy, can hardly be carried around in lab. Also, the screen only supports mono-color display. Additionally, it has no play-back function for any sampled waves. Even now, the product is still expensive (~$3,000).
2.2 Product #2
Fig. 2.2 DSO nano V2
A pocket-size device designed for basic EE tasks.
For the aspect of convenient, this product is similar to our design in many ways. Major features of the device are portable size, proper measurement range, color displays, simple packaging, and playback function.
Although continent in use, the device has a limited screen size and short battery life, so it will not sustain continuous use. Also the playback function is not a full-copy of the original signal. It only gives back the shape and major feature of the original signal.
The features we will reference and implement in our design are the size and the reconstruction of the signal. Due to the limitation of using a battery, a sustainable power supply will be implemented in our design instead of battery.
This product is highly compact and easy-portable (palm size), multi-color LCD display. Although small in size, it has abundant measurement that can satisfy almost all EE use. Moreover, it has a built-in function generator. The price is also reasonably acceptable ($94).
The disadvantages of the product are majorly limited screen size, and short battery life (1 hour).
3.0 Project Packaging Specifications
The package of the device is a stand-alone box that has the proper input/output. All the I/O ports are on the box. By reference the products in the market, general plastic case was determined to be the best choice for packaging.
The device was designed for general laboratory use, so as long as the size and weight is easily portable (doesn’t have to be “palm size”), it would be acceptable.
The material for packaging will be LPDE (low cost); unless extreme case happening during future test (i.e. melting, inability of holding the structure) will we change the material for better plastic cases.
In conclusion, the packaging constraints are: 1. Portability, must be easy to transfer by hand. Light-weight: 20 lbs or less in total weight. 2. Operating environment: ±10 ºC around room temperature. Chassis fan would provide such environment, however if the constraints cannot be made by a chassis fan, other heat-sink method would be implement. The interface (keypad, RPGs, and VGA) should be easy to use by students with basic oscilloscope knowledge.
4.0 PCB Footprint Layout
The three components previously identified as major elements of the project include the STM microprocessor and Spartan 3E FPGA for digital components; and analog components are Op-amp (2 types), precision resistors, DC/DC converter, Voltage regulator (2 types), and ports for other off-chip components (LED, LCD, Input/ Output port).
After searching parts online, we found that most parts have only 1 type of size/ packaging. Fortunately the parts fit our design consideration. Detailed parts packaging/ size see attachment.
After some optimization of our initial layout, out PC board size conclude to be 225mm X 180 mm (digital components); and 150mm X 120 mm (analog components). PC board interconnects via on-chip pin port, so it will protect the digital chip sinking too much current.
5.0 Summary
This report summarizes our packaging constrains and presents a preliminary layout of the two PC boards. We conclude our design constrains as portability (easy to move by hand, both proper size and light weight), proper operation temperature and user-friendly interface.
List of References
[1] DSO nano v2 manual v9.01B [Online], May. 2011. Available: http://www.seeedstudio.com/depot/datasheet/DSO%20Nano%20v2%20Manual.pdf [Accessed: Feb 7, 2012].
[2] Prof. Dr. –Ing. K. –D. Kammeyer [Online], April. 2010. Available: http://www.ant.uni-bremen.de/whomes/rinas/agiload/ [Accessed: Feb 7, 2012].
[3] MetricTest, Agilent 54621A 60MHz 2CH 200MSa/s Oscilloscope [Online], 2010. Available: http://www.metrictest.com/product_info.jsp?mfgmdl=HP%2054621A(N) [Accessed: Feb 7, 2012].
-4-
ECE 477 Digital Systems Senior Design Project Rev 2/12
Appendix A: Project Packaging Illustrations
Case size (approximate) 250 mm * 200 mm * 100 mm
Appendix B: Project Packaging Specifications
Table B.1 Basic package type of components
Other constrains: the packaging should be as compact as possible, however the case should also provide enough space between analog and digital board to effectively prevent interference during sampling data
Vendor / Manufacturer / Part No. / Description / Packaging/ size(mm) /Qty
/Total Price
Digi-Key / STMicroelectronics / STM32F407VGT6 / ARM Cortex-M4 32b MCU+FPU / LQFP10017*17*1 / 1 / $16.00
Digi-Key / Xilinx / XC3S500E-4FG320C / Spartan-3E FPGA Family / --
110*65*5 / 1 / $34.98
Digi-Key / Maxim / MAX5490TA05000 / 100kΩ Precision-Matched Resistor-Divider in SOT23 / 3-pin SOT32
3.04*1.4*1.12 / 18 / $13.96
Digi-Key / National Semiconductor / LMH6703 / Low Distortion Op Amp with Shutdown / 8-pin SOIC
5*4*1.75 / 12 / $23.22
Digi-Key / Panasonic / ELK-E333FA / Coil type EMI Filters / Embossed taping
10*6.5*3.3 / 2 / $2.88
Digi-Key / Liner Technology / LTC1174HVCS8-3.3 / High Efficiency Step-Down and Inverting DC/DC Converter / 8-pin PDIP
5*4*1.75 / 1 / $8.30
Maxim / Maxim / MAX14752 / 8 to 1 Analog Multiplexer / 16TSSOP
6.6*5*1 (may change) / 3 / $7.50
Digi-Key / Analog Device / OP07 / High-Voltage OP amplifier / 8-pin SOIC
5*4*1.75 / 6 / $4.32
Total / $111.16
Appendix C: PCB Footprint Layout
Overview of PCB1
PCB1 Layout (Preliminary)
Overview of PCB2
PCB2 Layout (Preliminary)
-4-