Issue 328 November: EQ Questions

EQ

Review these four Test Your EQ problems that appeared in Circuit Cellar November (328). Test your knowledge. Answers appear in the December issue (329) Question 1—USB is by far the most common way to connect peripherals to PCs these days, yet … Continue reading

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Issue 326 September: EQ Questions

EQ

Review these four Test Your EQ problems that appeared in Circuit Cellar September (326). Test your knowledge. Answers appear in the October issue (327) . Question 1 Asynchronous (dual-clock) FIFOs are important functions in high-speed digital design, especially when data needs … Continue reading

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Issue 324: EQ Questions

EQ

Review these four Test Your EQ problems that appeared in Circuit Cellar 324. Test your knowledge. Answers appear in issue 325. Problem 1: In the following circuit, pick a value for Rx that sets the quiescent voltage at the collector to … Continue reading

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Issue 322: EQ Answers

EQ

Here are the answers to the four EQ problems that appeared in Circuit Cellar 322. Problem 1: Some time ago (Issue #274), we discussed how theoretical channel capacity is a function of the bandwidth and the signal-to-noise ratio of the … Continue reading

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Issue 320: EQ Answers

EQ

Problem 1: A certain CPU has three blocks of combinatorial logic that are used in each instrucion cycle, and these have delays of 7 ns, 3 ns, and 10 ns, respectively. A register in this technology has a total of 2 ns of setup … Continue reading

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Issue 318: EQ Answers

EQ

Here are the answers to the four EQ problems that appeared in Circuit Cellar 318. Problem 1: Outside of simply moving data from one place to another, most of the work of a computer is performed by “dyadic” operators — … Continue reading

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Issue 316: EQ Answers

EQ

Question 1: What is the second grid in a tetrode vacuum tube for? How about the third grid in a pentode? Answer 1: In a triode, there is a certain amount of capacitance between the control grid and the plate, which contributes … Continue reading

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Issue 314: EQ Answers

EQ

Answer 1—Intersymbol interference is created by nonlinearities in the phase/frequency response of the RF channel. These irregularities are generally proportional to the carrier frequency — for example, if a channel centered at 1 MHz has a quality factor (Q) of … Continue reading

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Issue 312: EQ Answers

EQ

Question 1: What is the probably of a flip-flop with a uniformly-distributed asynchronous input going metastable? Answer 1: The probably that a flip-flop with a uniformly-distributed asynchronous input will go metastable is a function of how wide its “window of opportunity” (the … Continue reading

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Issue 310: EQ Answers

EQ

Answer 1: UDP packets are subject to the following problems. Packets may be lost. Packets may experience variable delays. Packets may arrive in a different order from the order they were transmitted. UDP gives the application the ability to detect and deal with … Continue reading

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Issue 308: EQ Answers

EQ

Problem 1—The circuit shown below is an audio amplifier with a slightly unusual topology. Explain how to analyze its DC operating point.  Answer 1—For the DC analysis, start by calculating the Thevenin equivalent of the bias network: 8.0 V and 16.67 kΩ. … Continue reading

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Issue 304: EQ Answers

EQ

Problem 1—The following circuit was designed to be an inrush current limiter for the large (40,000 µF) capaitor C1. R7 represents the application load of about 180 mA at 9 V. The load on the 9-V source (Vin) needed to … Continue reading

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Issue 302: EQ Answers

EQ

Problem 1: You have decided to build a small computer from discrete transistors as a demonstration. After researching the available technologies, you have decided to base your design on NMOS logic, using a 3-input NOR gate as your basic building block, … Continue reading

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Issue 300: EQ Answers

EQ

Problem 1: The diagram below is a simplified illustration of a switchmode “buck” DC-DC converter with synchronous (active) rectification. The switching elements are shown as MOSFETs, with the associated body diodes drawn explicitly. The details associated with driving the MOSFET gates … Continue reading

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Issue 298: EQ Answers

EQ

Problem 1: What do we call a network of gates that has no feedback of any kind? What is its key characteristic? Answer 1: A network of gates that has no feedback is called “combinatorial logic”, or sometimes “combinational logic”. Its defining characteristic … Continue reading

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