Analog - Chap 3-4 PDF

IC Technology Integrated Circuits (ICs) An IC is a collection of electronic components -- resistors, transistors, capacitors, etc. -- all stuffed into a...

IC Technology Integrated Circuits (ICs) An IC is a collection of electronic components -- resistors, transistors, capacitors, etc. -- all stuffed into a tiny chip, and connected together to achieve a common goal. They come in all sorts of flavors: single-circuit logic gates, op amps, 555 timers, voltage regulators, motor controllers, microcontrollers, microprocessors, FPGAs, etc. Integrated Circuits (ICs) are also known as microchips or microelectronic circuit, it is a semiconductor wafer that holds thousands and millions of resistors, capacitors, and transistors. It is basically an assembly of electronic components that’s fabricated as a single unit. Integrated Circuits (ICs) Inside Integrated Circuits (ICs) Ref: Hitachi-hightech Inside Integrated Circuits (ICs) The image above then shows how an IC chip looks like under an X-ray through 3D rendering, it features complex structures with multiple layers that forms an IC chip. Ref: Physics world Integrated Circuits (ICs) Figure 1. In 1962, four women programmers hold parts of the first four Army computers. From left is the ENIAC board, EDVAC board, ORDVAC board, and the BRLESC-I board. Image courtesy of the US Army. Scale of Integrated Circuits (ICs) Scale of Integrated Circuits (ICs) SSI MSI LSI VLSI ULSI Figure 1: Analog Signal Figure 2: Analog Circuit Figure 1: Digital Signal Figure 2: Digital Circuit  A FinFET is a type of field-effect transistor (FET) that has a thin vertical fin instead of being completely planar. The gate is fully “wrapped” around the channel on three sides formed between the source and the drain. The greater surface area created between the gate and channel provides better control of the electric state and reduces leakage compared to planar FETs. Using FinFETs, results in much better electrostatic control of the channel and thus better electrical characteristics than planar FETs. Fig. l. A structure of monolithic 3D IC based on FinFET technology. https://www.synopsys.com/glossary/what-is-a-finfet.html Integrated Circuits Fabrication Techniques The starting material for integrated circuits fabrication is Single crystal silicon wafer. 1. Layering The layering step serves to add thin layers to the surface of the wafer. These layers may be of a different material, microstructure and composition of the same material such as polycrystalline silicon and silicon oxide. Back End Of Line (BEOL) Integrated Circuits Fabrication Techniques The starting material for integrated circuits fabrication is Single crystal silicon wafer. 2. Patterning The most important step in wafer fabrication is patterning or lithography. The deposition, doping, etching, and patterning refer to a series of steps to selectively mask or expose portions of the surface. It sets the device’s critical dimensions on the wafers. Polyethylene terephthalate glycol (PETg) Indium tin oxide (ITO) Polymerized polydimethyl-siloxane (PDMS) Integrated Circuits Fabrication Techniques The starting material for integrated circuits fabrication is Single crystal silicon wafer. 3. Doping It is refers to the process of incorporating specific amounts of electrically active impurities through openings on the surface of the wafers. The doped materials are typically impurities of the type p or n and are necessary to form devices such as diodes , transistors, conductors and IC devices. Integrated Circuits Fabrication Techniques The starting material for integrated circuits fabrication is Single crystal silicon wafer. 4. Heat treatment, also called Furnace annealing It is a process used in the manufacture of semiconductor devices which consists of heating multiple wafers of semiconductors to affect their electrical properties. The heat treatments are designed for various effects. Wafers can be heated to enable dopants (doped material like phosphorus), transfer film to film or film to wafer substratum interfaces, densify deposited films, adjust grown film conditions, repair implant damage, shift dopants or drive dopants from one film to another or from a film to wafer substratum as shown in figure A. Integrated Circuits Fabrication Techniques The starting material for integrated circuits fabrication is Single crystal silicon wafer. 4. Heat treatment, also called Furnace annealing It is a process used in the manufacture of semiconductor devices which consists of heating multiple wafers of semiconductors to affect their electrical properties. The heat treatments are designed for various effects. Wafers can be heated to enable dopants (doped material like phosphorus), transfer film to film or film to wafer substratum interfaces, densify deposited films, adjust grown film conditions, repair implant damage, shift dopants or drive dopants from one film to another or from a film to wafer substratum as shown in figure A. https://youtu.be/_VMYPLXnd7E Quantum Computer Quantum computer Intel Corporation’s 49-qubit quantum computing test chip, code-named “Tangle Lake,” is unveiled at 2018 CES in Las Vegas. (Credit: Walden Kirsch/Intel Corporation) U.S. President Joe Biden stands next to a quantum computer Quantum computer “Quantum computing takes advantage of the strange ability of subatomic particles to exist in more than one state at any time. Due to the way the tiniest of particles behave, operations can be done much more quickly and use less energy than classical computers” — BEALL, A (2018) Quantum computer OPERATIONAL AMPLIFIER  AMPLIFIER IT IS AN ELECTRONIC CIRCUIT OR DEVICE WHICH INCREASES THE AMPLITUDE OF A SIGNAL  OPERATIONAL AMPLIFIER (OP AMP) HISTORICALLY AN OP AMP WAS DESIGNED TO PERFORM SUCH MATHEMATICAL OPERATIONS AS ADDITION, SUBTRACTION, INTEGRATION AND DIFFERENTIATION. HENCE THE NAME OPERATIONAL AMPLIFIER.  Background Originally invented in early 1940s using vacuum tube technology – Initial purpose was to execute math operations in analog electronic calculating machines Shrunk in size with the invention of the transistor Most now made on integrated circuit (IC) Huge variety of applications, low cost, and ease of mass production make them extremely popular ICs FAIRCHILD SEMICONDUCTORS NATIONAL SEMICONDUCTORS ΜA 702 (1963) LM101 (1967) ΜA 709 (1965) LM101A (1968) ΜA 741 (1968) LM107 (1968) ΜA 748 (1968) LM324 (1974) 741 Op-Amp –Internal Circuitry  OP AMP – A MULTISTAGE AMPLIFIER DIFFERENTIAL AMPLIFIER STAGE HIGH GAIN CE AMPLIFIER STAGE CLASS B PUSH PULL EMITTER FOLLOWER Differential More stages of Class B Push Amplifier gain pull Amplifier Op Amp Equivalent Circuit  IDEAL OP AMP PRACTICAL OP AMP ZIN = ∞ ZOUT = 0 ZIN = 2MΩ AVOL =∞ ZOUT = 100Ω BW = ∞ AVOL = 105 BW = GHZ Voltage Transfer Characteristic Range where we operate the op amp as an amplifier. Vin APPLICATIONS Non-Inverting Amplifier Inverting Amplifier Op-Amp Summing Amplifier Op-Amp Differential Amplifier If R1 = R2 and Rf = Rg:  Op-Amp Integrator Vo = - Op-Amp Differentiator Low-pass Filter (active) Cutoff frequency This works because the capacitor needs time to charge. High pass filter (active) Applications of Op-Amps Electrocardiogram (ECG) Amplification – Need to measure difference in voltage from lead 1 and lead 2 – 60 Hz interference from electrical equipment  Simple ECG circuit – Uses differential amplifier to cancel common mode signal and amplify differential mode signal Realistic ECG circuit – Uses two non-inverting amplifiers to first amplify voltage from each lead, followed by differential amplifier – Forms an “instrumentation amplifier” Strain Gauge Use a Wheatstone bridge to determine the strain of an element by measuring the change in resistance of a strain gauge (No strain) Balanced Bridge R #1 = R #2 (Strain) Unbalanced Bridge R #1 ≠ R #2  Half-Bridge Arrangement Op amp used to amplify output from strain gauge R + ΔR Rf Vref R + Vcc + - - + - Vcc + R V0 R - ΔR __ Rf Using KCL at the inverting and non-inverting terminals of the op amp we find that ➔ ε ~ Vo = 2ΔR(Rf /R2)  Op Amps Applications Audio amplifiers – Speakers and microphone circuits in cell phones, computers, mpg players, boom boxes, etc. Instrumentation amplifiers – Biomedical systems including heart monitors and oxygen sensors. Power amplifiers Analog computers – Combination of integrators, differentiators, summing amplifiers, and multipliers THANK YOU