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Transistor Differential Amplifier - Look under the hood of most op amps, comparators or audio amplifiers, and you'll discover this powerful front-end circuit, the differential amplifier. A simple circuit able to amplify small signals applied between its two inputs, yet reject noise signals common to both inputs. This circuit has a unique topology: two inputs and two outputs. Although you can tap the signal from one output only, taking the difference between (spice design) __
Translate TTY Current Loop to Rs-232 - 08/01/98 EDN Design Ideas: (NOTE: Multiple circuits in this file, scroll to find this one.) The circuit in Figure 1a provide as signal translation between a passive current-loop (TTY) interface and a duplex RS-232C port. The current flowing in the receiver loop causes the transistor to pull down RxD; when the transistor turns off, R1 pulls up RxD. In like manner, the current in the transmitter loop switches on for a negative TxD voltage and off for a positive voltage. Design by Jerzy Chrzaszcz, Warsaw University, Poland
Transmission Line Terminations - (spice design) __ Designed by Rick
Triangle Wave Generator - This signal generator gives you two waveforms for the price of one: a triangle-wave and a square-wave. What is the central component of this circuit? The integrator capacitor Ci. Basically we are interested in performing two functions on Ci: charge it, discharge it, repeat indefinitely. During the design process, we ask these (spice design) __
Use PSpice for behavioral Modeling of VCOs - 12-Dec-02 EDN Design Ideas: PSpice, a member of the Spice family for PC users, is becoming a standard tool for analog and mixed analog-digital simulation. Many analog designers are familiar with the software of Design Center, Design Lab, and OrCad (www.orcad.com] PSpice and use the software in their everyday lives. This design idea should be heLPFul to those who design and simulate PLL systems at a behavioral level Design by Dobromir Dobrev, Jet Electronics, Sofia, Bulgaria
Use PSpice to Model distributed-gap cores - 03/17/05 EDN Design Ideas: PSpice software lets you create magnetic-core models that simulate nonlinear magnetic devices (Figure 1). These simulations are useful for observing hard-to-measure magnetic parameters such as core flux density, especially when you cannot quickly procure a sample device. The required inputs to the PSpice magnetic-core model are initial permeability of the core material, data poin Design by Jeff Fries, GE Transportation Systems Global Signaling, Grain Valley, MO
Variable Length 22AWG Twisted Pair Transmission Line SPICE Model - Very good working four port subcircuit model of a transmission line. Can be adapted to CAT5 and others. Length of line defined by 1ft = 1V. __ Designed by Jim Haggerman, Hagerman Technology LLC
Voltage Regulator w/ Series-Pass Transistor - What is the function of a voltage regulator circuit? it’s basically this, maintain a precise voltage regardless of the current drawn by the load. Three basic components are needed to achieve good voltage regulation (spice design) __
Voltage-Controlled Resistor - A common request from SPIC E users is a voltage-controlled resistor. Although there's no SPIC E component that directly models this device, you can easily put one together. There's several ways to do it. You can even extend the device to model more complex resistance functions like RTDs and thermistors (spice design) __
Wien Bridge Oscillator - The OpAmp Wien-bridge oscillator provides a nice view into classic oscillator design using feedback analysis. Feedback analysis reveals if your circuit is stable (well behaved) or unstable (may oscillate). When designing amplifiers (especially high-speed ones) , the trick is to avoid the conditions that make the circuit oscillate. When designing oscillators, you strive to achieve those conditions in a predictable way.__ |
