Unit 1 - EE603

EE603UNIT 1INTRODUCTION TO INTEGRATED CIRCUITPrepared by Azhani binti Hashim1The History of the Integrated CircuitThe world full of Integrated Circuit (IC).Examples : ??An electric circuit is made from different electrical components such as transistors, resistors, capacitors and diodes, that are connected to each other in different ways. Which one is the most important?2Transistor EvolutionTransistor is the most important one for the development of modern computers.Before, engineers had to use vacuum tubes.The replacement due to:generates a lot of heat and has a tendency to burn out.Slow, big and bulky.3Transistor Evolution

The first digital computer ENIAC was a huge monster that weighed over thirty tons, and consumed 200 kilowatts of electrical power. It had around 18,000 vacuum tubes that constantly burned out, making it very unreliable.4Transistor EvolutionWhen transistor invented?Who created it?The first transistor was invented at Bell Laboratories on December 16, 1947 by William Shockley (seated at Brattain's laboratory bench), John Bardeen (left) and Walter Brattain (right). This was perhaps the most important electronics event of the 20th century, as it later made possible the integrated circuit and microprocessor that are the basis of modern electronics.5Transistor EvolutionTyranny of NumbersWith the small and effective transistor, constructing advanced circuits more easier than before.Advanced circuits brings complex and more component. Resulting problem in size, speed and construction.Solution: Monolithic by Jack Kibly.6Transistor EvolutionMonolithic was to make all the components and the chip out of the same block (monolith) of semiconductor material.By making all the parts out of the same block of material and adding the metal needed to connect them as a layer on top of it:no more for individual discrete components. no more wires and components had to be assembled manually.the circuits could be made smaller.the manufacturing process could be automated.

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8MOSFET HistoryThe first MOSFET transistor was invented at Canada in 1925 and England in 1935.PMOS in 1960s and mostly used in calculators.NMOS in 1970s and mostly used in (4004, 8008 microprocessor) for speed.CMOS in 1980s is the preferred MOSFET technology because of power benefit.

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20COST OF INTEGRATED CIRCUITTotal cost of can be separated into two components:Variable cost (recurring expenses)Cost that is directly attributable to a manufactured product and hence propotional to product volume.Examples : cost of the part used in the product, assembly cost, testing cost , design time and effort

die yield the number of good die divided by the number of die tested.21COST OF INTEGRATED CIRCUITFixed cost (non-recurring expenses)Effort in time and manpower it takes to produce the design.Influenced by the complexity of the design, the aggressiveness of the specifications, and the productivity of the designer.Indirect cost R&D, manufacturing equipment, marketing, sales and building infrastructure.22COST OF INTEGRATED CIRCUIT

23FUNCTIONALITY AND ROBUSTNESSNoiseIn digital circuit, it means unwanted variations of voltages and currents at the logic nodes.Three noise sourceWire noiseInductive coupling noiseCapacitive coupling noise power supply noise and ground noise expressed in volt and ampere.24FUNCTIONALITY AND ROBUSTNESSNoise source (wire noise)

two wires placed side by side in an integrated circuit form a coupling capacitor and a mutual inductance.

25FUNCTIONALITY AND ROBUSTNESSNoise source (power supply noise)

Noise on the power and ground rails of a gate also influences the signal levels in the gate.

26FUNCTIONALITY AND ROBUSTNESSVoltage Transfer Characteristic (inverter)

Gate / Switching threshold voltagehigh nominal voltageMathematical function :VOH = f(VOL)VOL = f(VOH)VM = f(VM)low nominal voltage27FUNCTIONALITY AND ROBUSTNESSVoltage Transfer Characteristic

28FUNCTIONALITY AND ROBUSTNESSNoise MarginFor a gate to be robust and insensitive to noise disturbances, it is essential that the 0 and 1 intervals be as large as possible.measure of the sensitivity of a gate to noise is given by the noise margins NML (noise margin low) and NMH (noise margin high).Noise margin is the ability to overpower the noise.29FUNCTIONALITY AND ROBUSTNESSNoise Margin

30FUNCTIONALITY AND ROBUSTNESSNoise MarginA large noise margin is a desirable, but not sufficient requirement. Assume that a signal is disturbed by noise and differs from the nominal voltage levels. As long as the signal is within the noise margins, the following gate continues to function correctly, although its output voltage varies from the nominal one.

31FUNCTIONALITY AND ROBUSTNESSNoise Immunityexpresses the ability of the system to process and transmit information correctly in the presence of noise.Why most digital circuits have very good noise immunity?noise immunity is the ability to reject the noise source.32FUNCTIONALITY AND ROBUSTNESSDirectivityThe directivity property requires a gate to be unidirectional, that is, changes in an output level should not appear at any unchanging input of the same circuit. If not, an output-signal transition reflects to the gate inputs as a noise signal, affecting the signal integrity.In real gate implementations, full directivity can never be achieved. Some feedback of changes in output levels to the inputs cannot be avoided. Capacitive coupling between inputs and outputs is a typical example of such a feedback. It is important to minimize these changes so that they do not affect the logic levels of the input signals.33FUNCTIONALITY AND ROBUSTNESSFan-outThe fan-out denotes the number of load gates N that are connected to the output of the driving gate.Increasing the fan-out of a gate can affect its logic output levels.Propagation delay, rise time and fall time affected by the fan-out due to larger capacitance loads.

34FUNCTIONALITY AND ROBUSTNESSFan-infan-in of a gate is defined as the number of inputs to the gate.Gates with large fan-in tend to be more complex, which often results in inferior static and dynamic properties.

35FUNCTIONALITY AND ROBUSTNESSIdeal gate

properties: infinite gain in the transition region.gate threshold located in the middle of the logic swing.with high and low noise margins equal to half the swing. Input impedances are infinity.Output impedances and zero.36FUNCTIONALITY AND ROBUSTNESSNMOS inverter of the 1970s.The observed transfer characteristic, obviously, is far from ideal: it is asymmetrical, has a very low value for NML, and the voltage swing of 3.05 V is substantially below the maximum obtainable value of 5 V (which is the value of the supply voltage for this design).

37QUESTIONSWhat is VM, VOH, VOL?

38QUESTIONSNoise margin is the ability to _____________ the ______. But noise immunity is the ability to _______ the ________.Properties of ideal gate is: Input impedances are ________.Output impedances and _______.

39PERFORMANCEPropagation DelaysThe propagation delay tp of a gate defines how quickly it responds to a change at its input(s). It expresses the delay experienced by a signal when passing through a gate. It is measured between the 50% transition points of the input and output waveforms.40PERFORMANCEPropogation delays

41PERFORMANCEPropagation delaystpLH defines the response time of the gate for a low to high (or positive) output transition, while tpHL refers to a high to low (or negative) transition. The propagation delay tp is defined as the average of the two.

42Propagation delay and power consumptionThe propagation delay is mostly determined by the speed at which a given amount of energy can be stored on the gate capacitors. The faster the energy transfer (or the higher the power consumption), the faster the gate is. A faster energy transfer requires a higher power consumption which resulted in a faster gate operation.43PERFORMANCERise time & fall time

Rise time is the time required for the logic signal to rise from 10% to 90%.Fall time is the time required for the logic signal to rise from 90% to 10%.44PERFORMANCEPower and energy consumptionThe power consumption of a design determines how much energy is consumed per operation.Factors : power-supply capacity, battery lifetime, supply-line sizing, packaging and cooling requirement.Three types of power dissipation:Peak power : supply-line sizing.Instantanenous power : power-supply capacity.Average power : cooling and battery requirement.45Power consumption determines heat dissipation and energy consumptionPower influences design decisions:packaging and coolingwidth of supply linespower-supply capacity# of transistors integrated on a single chip

46Propagation delay is related to power consumptiontp determined by speed of charge transferfast charge transfer => fast gatefast gate => more power consumptionCMOS technology:No path exists between VDD and VSS in steady stateNo static power consumption! (ideally)Main reason why CMOS replaced NMOS47