Ultra Miniature Surface Mount Transistor 2/17/94 - App Note Doc #906__ California Eastern Laboratories
Unijunction Transistor - The unijunction transistor (UJT) is a three terminal device with characteristics very different from the conventional 2 junction, bipolar transistor. it is a pulse generator with the trigger or control signal applied at the emitter. This trigger voltage is a fraction (n) of interbase voltage, Vbb. The UJT circuit symbol, junction schematic, and characteristic curve are__ American Microsemiconductor
Universal DC Sink to Source Converter - As illustrated below, many control systems use an open collector transistor to turn something on. Perhaps it is a LED light, a relay or a small motor. However there are other systems which require a common ground connection instead of a common V+ supply . . . Hobby Circuit designed by David A. Johnson P.E.-March, 2011
Use a Transistor & an AM meter to Measure Inductance - 04/05/12 EDN Design Ideas: Bipolar junction transistors transfer a current from a lower-resistance emitter to a higher-resistance collector. You can use this property to measure inductance. Design by Raju Baddi, Tata Institute of Fundamental Research, Pune, India
Use a Transistor as a Heater - 04/19/12 EDN Design Ideas: A temperature sensor and a hot transistor hold biological samples at a preset temperature. it is common to use transistors for driving resistive heating elements. However, you can use the heat that a power transistor dissipates to advantage in several situations, eliminating the need for a separate heating element because most transistors can safely operate at temperatures as high as 100°C. A typical example is in a biological laboratory, in which the need for maintaining the temperature of samples in microliter-sized cuvettes is a common requirement. Design by REC Johnson, B Lora Narayana, and Devender Sundi, Center for Cellular and Molecular Biology, Hyderabad, India
Use Op Amps to Make Automatic-Oring Power Selector - 08/11/11 EDN Design Ideas: Replace diodes with FETs to reduce power loss. Many systems must select among two or more low-voltage dc-input sources, such as an ac adapter, a USB (Universal Serial Bus) port, or an onboard battery, for example. You can implement this selection using manual switches, but automatic switching is preferable. You usually want to use the highest-available input voltage to power your system. You can accomplish this task using a Schottky-diode ORing scheme (Figure 1). Unfortunately, the forward-voltage drop of a Schottky diode ranges from 300 to 600 mV. This voltage wastes power, creates heat, and decreases the voltage available to your system. Design by Bobwicker, Analog Devices, Fort Collins, CO
VCOM adjustment uses any logic-supply voltage - 09/30/04 EDN Design Ideas: All TFT [thin-film-transistor] LCD panels require at least one appropriately tuned VCOM signal to provide a reference point for the panel’s backplane. The exact value of VCOM varies Page includes several designs. Scroll to find this one Design by Peter Khairolomour and Alan Li, Analog Devices, San Jose, CA
Verilog code Models boundary-scan TAP machin - 04/27/95 EDN Design Ideas: Listing 1 shows a Verilog behavioral model for the Test Access Port (TAP) controller for boundary-scan test circuitry. Boundary scan is one of the most popular methods to scan the internal nodes of a circuit. The test circuitry for the boundary scan consists of the following: a boundary-scan register, a bypass register, an instruction register, and the TAP controller. The principal of operation Design by Swapnajit Mittra, Wipro Infotech Ltd, Bangalore, Karnataka, India
Verilog Program Models Metastable Flip-Flop - 05/12/94 EDN Design Ideas: The Verilog HDL program in Listing 1allows you to simulate the behavior of a set-reset (SR] flip-flop that has both its set and reset inputs high simultaneously. The outputs of a physical SR flip-flop become indeterminate in this condition. This property is the basis of circuits such as random-number and pseudo-noise-sequence (PSN] generators Design by Swapnajit Mittra, WIPRO Infotech Inc, Beaverton, OR
Very Basic 12 volt Inverter - This circuit will provide a fairly stable "Square Wave" Output Voltage. Frequency of operation is Mainly determined by the 220 uF Feedback Caps. Currently about 60 Hz. Various "off the shelf" transformers can be used. __ Designed by G.L. Chemelec
Very Low Power Astable Multivibrator - This classic circuit draws only 200 nanoamps from a 1.5v supply. . . Circuit by David A. Johnson P.E.-June, 2000
VHDL & Verilog fundamentals - 02/03/97 EDN-Design Feature To successfully design chips with Verilog or VHDL, you need to understand the basics of these hardware-description languages. Design by Douglas J Smith, VeriBest
VHDL code implements 50%-duty-cycle divider - 08/15/97 EDN Design Ideas: Realizing a 50%-duty-cycle, divided-down clock is not always a trivial task, particularly when the divisor rate is an odd number. You can use the VHDL source code in Listing 1 to synthesize an FPGA or a CPLD circuit that produces a 50%-duty-cycle waveform for any Design by Brian Boorman, Harris RF Communications, Rochester, NY
VHDL customizes serializer/deserializer - 06/05/00 EDN Design Ideas: Many applications require a multiple-signal exchange among cards through a backplane. Several solutions are available to serialize/deserialize data—from the classic UART to newer low-voltage differential-signaling components. it is sometimes important to have hardware flexibility in transferring signals; for example, Design by Antonio Di Rocco, Siemens ICN, L’Aquila, Italy
VHDL procedure dynamically opens a file - 12/17/98 EDN Design Ideas: (File contains many circuits. Scroll to find this one.) A simple VHDL-87 procedure opens a file whose name a command file or user conveys in runtime. You can apply this technique to the reading or writing of data, control, and status files. This procedure is useful for replacing the input stimulI file of a testbench without recompiling the code (with a different stimulI file name) or rename the stimulI file name. in addition, the procedure can write the simulation results to a file whose name consists of the input file name and any preferred extension. Design by Jacques Behar, Rockwell Semiconductor Systems, San Diego, CA
VHDL produces CRC checker - 08/03/00 EDN Design Ideas: CRC (cyclic-redundancy checking) allows you to verify the integrity of transmitted data frames. it finds use in many transmission protocols, both bit-oriented (High Level Data Link Control, Advanced Data Communications Control Procedure, CRC-CCiTT, for example) and frame-oriented (asynchronous transfer mode, Ethernet, Fiber Distributed Data interface, for example) Design by Antonio Di Rocco, Siemens ICN, L
Visualbasic Does I/O - 02/17/94 EDN Design Ideas: Microsoft's VisualBasic—which runs under Windows—cannot operate on a PC's i/O ports. However, you can add dynamic-link libraries (DLLs] to extend the keywords of native VisualBasic (Listing 1]. The compiled code, listings, and documentation in ZiPfile Di1167Z. ZiP (attached to EDN BBS /Di_SiG #1367] let you Design by Jon Titus, Test & Measurement World, Newton, MA
Voltage Controlled Resistor - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Voltage reference improves JFET - 26-Oct-00 EDN Design Ideas: The common JFET current-source in Figure 1a has average output impedance and depends heavily on the JFET's VP and iDSS variations. These manufacturing variations limit the initial accuracy of the current setpoint that the circuit can obtain with a fixed R1. Most users of JFET current-sources sample VPPDF has several circuits, scroll to find this one Design by Clayton Grantham, National Semiconductor, Tucson, AZ
Voyager 2 FM Radio Bug - VOYAGER is a super-sensitive FM Radio microphone developed by Talking Electronics. The components are all common types of resistors, capacitors and transistors matched so well in this circuit that amazing sensitivity and distance are obtained. The name VOYAGER was given to it "because it goes so far". We have re-designed the Board and further matched some components to suit the needs of the classroom. The result is a superb bug which is compact but powerful, and quite easy to build__ CdS Electronic |