1. ECE 477 DESIGN REVIEW TEAM 2  FALL 2011 Members: Bo Yuan, Yimin Xiao, Yang Yang, Jintao Zhang

2. Outline  Project overview  Project-specific success criteria  Block diagram  Component selection rationale  Packaging design  Schematic and theory of operation  PCB layout  Software design/development status  Project completion timeline  Questions / discussion

3. Project Overview  The project we propose is a digital oscilloscope with playback function that provides almost any function of a typical oscilloscope, such as digital sampling, signal processing, scaling, cursor setting, reconstruction and visualization of signals. Additional features such as recording and replicating signals as a function generator, and write data to external storage (SD card).

4. Project-Specific Success Criteria  An ability to sample analog voltage signal range from -12 V to 12 V via BNC;  An ability to reconstruct and display the sampled signal on VGA display;  An ability to create user interface and realize basic signal measurements, such as frequency and peak- to-peak voltage;  An ability to store/load the sampled signal to/from external memory;  An ability to replay a stored signal.

5. Block Diagram

6. Block Diagram, System Level

7. Component Selection Rationale  Power Supply:  Using a standard 20 pin-Computer power supply unit. (Easy to use)  Use linear transistor 7805/7905/78M33 to provide low noise signal. Although 5V and 3.3V are available from the power supply, but along with a ripple voltage at 300mV. No significant current will be drawn from +/-5V line, large ripple voltage will be used in driving the analog MUX (+/-12V) and FPGA module (+5V), which has its own on board linear power supply system.  Using a 3V voltage reference for A/D conversion reference.

8. Component Selection Rationale  Analog circuit:  MAX14752: Analog MUX Advantage: Large tolerance (VSS-2 to VDD+2) compare to ADG1414 (VSS- 0.3 to VDD+0.3). Easy to control: Serial bus control, no SPI line require. Got free sample from MAXIM, ADG1414 cost 8 dollar a piece. Disadvantage: High On-Resistance: 60 Ohm and ADG1414 is only 9.5 Ohm (Typ.). More Pins to MCU: Each require four lines to controller, but ADG1414 is SPI shift register which can be implemented serially.

9. Component Selection Rationale  INA118: Instrumentation Amplifier Advantage: low distortion, high tolerance (+/-40V), voltage shift up by V ref (1.5V).  LF411: Output driver op-amp: Advantage: Low offset, low distortion, high power (capable to drive coaxial wires)

10. Component Selection Rationale  Digital Circuit:  MCU – STM32F407VG Sampling rate 2.4 MHz maximum. Relatively large RAM size (192 KB).  Crystal Clock: 26MHz Crystal: Allowed maximum external clock. ARM Cortex- M4 will use an internal PLL to generate higher frequency clock up to 168MHz. Secondary clock (32.768KHz) is also laid out on board in case for need of precise clocking.  FPGA – Spartan 3E VGA support. Older version of the Spartan series, avoid voltage conversion.

11. Packaging Design

12. Schematic/Theory of Operation Analog Input/ Output

13. Schematic/Theory of Operation Microprocessor

14. Schematic/Theory of Operation Display Unit

15. Schematic/Theory of Operation User Interface

16. PCB Layout: General Layout

17. PCB Layout: Through Hole/Via

18. PCB Layout: Top Copper

19. PCB Layout: Bottom Copper

20. Software Design/Development Status

21. Software Design Development Status BlockProgress Timer ConfigDone I 2 C Master ConfigDone I 2 C Slave ConfigIn progress ADC ConfigDone with one channel GPIOsIn progress SubroutinesNot started DACNot started USBDone with config VGA displayNot started

22. Project Completion Timeline

23. QUESTIONS / DISCUSSION