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Home | Contact | Service List | Project List | Publications | Other Material | Related Links |
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Some examples of recent projects, activities, and interests are outlined below. |
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The picture on the top left shows a demonstrator board constructed for a PLL fundamentals course. The picture on the bottom left shows a sample of the corresponding course documentation. The diagram is used to explain a particular measurement setup. The material was initially intended for “at -presence” learning. However, the material also includes a comprehensive set of simulation files and experiments that the student can use to get up to speed prior to attending the lab sessions. The board and simulation files allow the student to carry out basic functional, step response, VCO gain, and phase transfer function measurements. In addition, principles of frequency and other measurements are introduced. Further motivations behind the material are outlined in a corresponding paper. A subset of the course material was also modified to work with a remote access laboratory at Limerick University (see publications page). This version allowed experiments to be carried out remotely via an internet link. Various modifications and additions to the material are planned. In addition, further courses of this type are being developed. If you are interested in the material please contact me. |
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The picture to the left shows a PIC based “generic” analogue I/O module. The unit uses the PIC’s onboard A/D for analogue data acquisition and two 256 position digital potentiometers for coarse voltage generation. The reverse side has a few leds and tact switches for status and control. Also, there is an EEPROM area for storage of values. The right hand side of the board shows a sil connector. This connector can be used to connect to an RS232 level shifter to allow PC communications. The same connector has also been used with an RF PIC and USB interface. The module was initially intended to be used in conjunction with a MAX038 function generator IC to allow control of the frequency adjust input on the MAX038. The specific purpose of this function was to allow a frequency modulated input to be applied at the reference input of the PLL measurement demonstrator board (see above). As time has progressed I have added some other functions that are of use to me. |
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As well as refinement and additions to the activities outlined above, I also have a number of other ongoing projects, some of which I am carrying out for my own interest. Key areas relate to development of DDS and PLL based synthesizers and data acquisition systems hardware. In addition, I have interests in sigma delta converters for communications applications. I am also developing further simulation based training material based upon the principals of the PLL course. In addition, I have professional and personal interests in electronics and technology related to renewable energy applications. Further information for these activities can be found at www.ecopivotal.co.uk The site will be updated as appropriate. |
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Most of these boards are experimental prototypes which I have used to carry out basic experiments relating to some PLL BIST / DFT test techniques. The board uses a relatively low speed true charge-pump version of the 74HCT4046 Pll chip. Im currently planning to upgrade this version with an off-chip higher frequency oscillator and perhaps some external high-speed logic. The second picture shows a PLL test board piggy-backed onto a Spartan II development board. This arrangement was used in for test evaluation in a similar manner to that of the first board, however, it was targeted to higher-frequency PLL’s . I’m also planning to proceed with the work in this area and look at refining the solutions and develop other techniques. The third picture shows an initial piggy back board that will be used to look at supply noise injection. Two key publications that I am eager to progress are shown here. If you are interested in some of this work please contact me. Some more details of the setups can be found in various publications.
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I have a variety of electronic spice circuit simulation files and corresponding course tutorial notes. The material covers basic circuit concepts, high-pass, low pass, RLC circuits , and various other op-amp, filter and transistor circuits. This material was initially developed to support basic undergraduate electronics lectures. However, the material includes sufficient background detail relating to the circuits to allow it to be delivered in a self contained manner. I also have a selection of more advanced modules that introduce basic MOSFET operation and techniques. In the past I have used the simulation files in conjunction with corresponding lab sessions based upon real hardware. I found that this methodology was particularly useful for emphasizing the difference between actual measurements and simulations. All simulations were developed for the B2SPICE simulator. However, they are easily adapted to other spice based simulators. The pictures to the right illustrate a MOSFET curve tracing simulation plot (top), an RLC circuit plot (middle), and a simple sample and hold circuit (bottom). I can deliver courses based on part or all of the material. I can also develop new material based upon customers requirements.
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Simulation and hardware demonstrator for a PLL fundamentals course |
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PLL test development boards and research |
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Other ongoing projects |
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Handheld low-speed analogue I/O /Data logger module module |
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Electronic circuit simulation modules |
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Project List |
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For more information: |
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1 kW E-Class Amplifier module (RF source) |
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The picture to the left shows a 1kW 13.56 MHz E-Class amplifier (RF-source) module that was designed and built for a client. The source has high efficiency, measured at typically greater than 87%. In addition, it has a small area (200 mm x 90 mm). The board was constructed as a 2-layer FR4 board. Various monitoring points were included and coupled to safety shutdown mechanisms (see below). The grey block at the top of the module is a plug in RF sensor linked to the external monitoring circuitry. |
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RF source safety shutdown circuit |
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The module on the right is a prototype unit that isolates the main supply to an RF source in the event of an error condition. The unit was used with the RF source shown above. The supply line switching capabilities are 300 V @ 7A. The module monitors heating temperature, supply current and drain voltage and automatically isolates the amplifier supply if an “over “ condition occurs. Extra inputs are included for monitoring of other parameters such as VSWR. |
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16-bit 80 Ms/s A/D board |
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The picture to the left shows a prototype 80 Ms/s, 16-bit DAQ board that I recently designed and constructed. The board contains a 64K x 18-bit FIFO, a Cypress EZ-USB micro as a high-speed USB interface. (This uses the BITWISE firmware), and an Analog devices AD9446 ADC. The board is 6-layer and was fabricated by PCB-POOL.
The topmost plot shows the output from the board with the following input signal. FSK: Deviation 500 kHz, Modulation 5 kHz
The bottom plot shows the output from the board with the following input signal. -10dBm, 10 MHz sine signal from a HP 33120A signal generator displayed over 64K samples. (BW: 40 MHz, 10 MHz, 1 MHz). |
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CPLD and PLL development board |
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The picture to the left shows a CPLD and PLL development board. The board is 4-layer and includes a USB interface a Xilinx CPLD an onboard PLL and a DDS chip. The board was initially developed for training purposes as an extension to the PLL course shown on this site. |
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MJBRF-Electronics Dr. Martin John Burbidge |
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Electronics and RF, research, development and prototyping. |