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There's more to transistors than just the basic type (MOSFET vs. JFET vs. BJT). CMOS, by definition, involves two types of MOSFETs (P-channel and N-channel). And not every transistor of the same type will be identical. For instance, the microcontrollers I work on use two voltages -- 3.3V for the IOs, and 1.2V for the core logic. The core transistors are ...


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Here is an awfully incomplete answer : By doping, oxyding, metallising a slice of sillicon, you can create on the surface several types of components : wires, bipolar transistors (aka BJT), metal-oxyde transistors (aka MOS), resistors, inductors, capacitors... (but it is often easier to create a transistor than these passive components). Components are ...


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Each logic family has different circuits for the same function (e.g. an AND gate), since each was an advance on earlier technology. The earliest logic families used bipolar junction transistors. Some examples are: RTL (1963) - resistor transistor logic (used in the Apollo Guidance Computer) DTL (1962) - diode transistor logic (used in the Minuteman II ...


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TTL logic uses bipolar transistors and CMOS logic uses, well, CMOS transistors. The structure of gates is also quite different between the two since the two types of transistors are so different and therefore need to be used differently.


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Here is a (slightly dated) paper that discusses the differences: http://www.ece.neu.edu/faculty/ybk/publication/ASSESSING_MERDRAM_ELSEVIER.pdf Basically, it boils down to a few important differences. Leakage current. The pass transistors for the DRAM cells must be extremely low leakage, otherwise the leakage current will affect the bit stored in the ...


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It might be easier to see this with an example. Let's take a look at the CD4001/CD4011 gates which are NOR or NAND gates respectively. Here is the internal schematic of a single NOR gate and a single NAND gate from the datasheet: You can ignore the four transistors that form the buffer for the output: Now for the NOR gate you can see that there are ...


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It's actually quite simple, and it's based on two requirements: Every node in the signal path must be connected to either Vcc or GND, to be at logical level 1 or 0 respectively; There should never exist a conductive path between Vcc and GND, else it will short the supply and start draining a lot of current and possibly burning some parts here and there. ...


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In general, CMOS inverters won't be able to source 3A. As Wouter van Oeijen stated, an H-Bridge is what you want. The princicple of operation is shown below. As shown, S_B1 and S_B2 are closed, causing a current flow from right to left. When you instead close the A-Switches, the current is reversed. When you want no current at all, open all switches. In ...


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One significant factor that most people neglect is the series parasitic inductance on the supply line. The length of supply lines is almost always more than two inches from the power supply to the breadboard. That means a huge parasitic series inductance for 16MHz. I suggest fitting a 10nF to 100nF ceramic capacitor next to the hole of pin 16 and pin 8 ...


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(answering from the comments) You could use a slower, inexpensive oscillator as your base clock, then use a PLL in the FPGA to generate various internal clocks at higher, lower or equal frequencies for use in your design. The functionality of the PLL's that are available to your design will depend on the type of FPGA; by way of example (modern) Xilinx ...


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UCLA apparently offers an undergrad program in semiconductor process engineering. You could suss out the course materials. See this and this. If you have access to the manuals for the expensive equipment used, you've got an advantage already. Note that it's offered by the chemical engineering faculty, and the electronics content is pretty minimal.



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