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Capacitor improves efficiency in CPU supply - 04/04/02 EDN Design Ideas: High efficiency is important for the DC/DC buck converters that supply high currents in notebook PCs. This efficiency extends battery life and minimizes temperature rise. A low-dissipation synchronous rectifier using an external MOSET provide as this high efficiency. Synchronous rectifiers require special attention, however Design by Masami Muranaka, Maxim Integrated Products, Tokyo, Japan
Caps Provide Voltage Boost to Series Regulator - This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range. it can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply. . . Circuit by David Johnson P.E.-January, 1998
Car Battery Charger - quickly and easily charge most any lead acid battery, automatically turns charging off when ready. __ Designed by Aaron Cake
Car Converter - 12V to 9V - To get a more precise output voltage, replace zener diode Z1 with 10V and R1 with a 1Kilo ohm potentiometer. A Coolrib for Q1 is optional but highly recommended. You can replace Q1 for a more robust type to get more output amps depending on your requirements. Simple circuit to power your 9 volt cassette recorder and other stuff __ Designed by Tony van Roon VA3AVR
Car NiCad Charger - This circuit provides up to20-Volt output from a regular13.2V automotive battery, to enable constant current charging of NIC d battery packs up to15 cells AT 1.2V (Tony van Roon's 18V total). __ Designed by Tony van Roon VA3AVR
Cascoded stack yields multiple voltages - 03/16/00 EDN Design Ideas: Although the cascode voltage-reference configuration in Figure 1 may seem obvious, the choice of R 1 and the bypass capacitors is critical. At first glance, stacking up references of the same voltage to produce a collection of voltages seems straightforward. However, nothing comes without precautions and an understanding of limitations. Design by Clayton Grantham
Ceramic output capacitors enhance internally compensated switchers - 07/20/06 EDN Design Ideas: Restore switching regulator stability when you change output-capacitor compositions Design by Robert Kollman, Texas Instruments, Dallas, TX
Change Improves Regulators’ Reliability - 05/12/94 EDN Design Ideas: The standard circuit for adjustable, 3-terminal regulators (LM317, LM350, etc.]in Fig 1a suffers from a designed-in fault if potentiometer R2’s wiper loses contact, regulator’s output goes high. Because potentiometer is most unreliable part in circuit, consider using circuit in Fig 1b. Now, Design by Peter Demchenko, VN, Vilnius, Lithuania
Charge Supercapacitors to 7V from USB Power - 04/26/07 EDN Design Ideas: Switching regulator charges three supercapacitors with current limit. Design by Fran Hoffart, Linear Technology, Milpitas, CA
Cheap pushbutton replaces rotary switch - 26-Oct-00 EDN Design Ideas: The problem of setting any one of four modes of aµC-operated process has a straightforward solution Have the µC check the states of some 4 bits of aµC. Design by Abel Raynus, Armatron International Inc, Melrose, MA
Cheap PWM IC makes synchronous gate driver - 02/04/99 EDN Design Ideas: NOTE: Page includes several designs. Scroll to find this one. A system with a µP, memory, and peripherals usually requires several power-supply voltages. Designers typically use local switching regulators to produce the desired voltage rails. One of the most common topologies, the synchronous buck regulator, converts a 5 or 12V bus to some other, lower voltage. This approach has gained vast acceptance, thanks to its relative simplicity Design by Dimitry Goder, Switch Power Inc, Campbell, CA
Chopping Reduces Reference’s Supply Current - 04/10/97 EDN Design Ideas: UPDATED Link! The 10V precision reference, IC 3, in Figure 1 has temperature drift of approximately 0.6 ppm/�C and good long-term stability. However, because of its zener-based design, this reference needs more than 4 mA of supply current. To reduce this current, the circuit in Figure 1 supplies the reference with chopped power. This scheme lowers the mean supply Design by Hartmut Henkel, von Hoerner & Sulger GmbH, Schwetzingen, Germany
Circuit adds foldback-current protection - 21-Jul-05 EDN Design Ideas: Enhance three-terminal regulator with foldback oversight Design by Rafael García-Gil and JM Espí, Electronic Engineering Department, University of Valencia, Spain
Circuit Charges Supercapacitors to 7V from USB Power - 04/26/07 EDN Design Ideas: Switching regulator charges three supercapacitors with current limit. Design by Fran Hoffart, Linear Technology, Milpitas, CA
Circuit Eliminates 9v Battery - if you use 9v battery powered devices for long periods of time, you may get tired of constantly changing batteries. The circuit below can be wired into any 9v battery powered device, drawing power from an external AC to DC power adapter. I designed the c . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2009
Circuit Forms Single-Pulse Voltage Multiplier - 18-Sep-03 EDN Design Ideas: it is sometimes necessary for a microcontroller to generate a pulse whose voltage is higher than the power-supply voltage of the microcontroller. The circuit in Figure 1 allows you to generate 14V pulses from a 5V power supply. An adaptation of the circuit provide as a 5 to 12V programming pulse for programming the fuse bits in Atmel (www Design by Richard Cappels, Mesa, AZ
Circuit improves on bias for GaAs FETs - 12/06/01 EDN Design Ideas: it's important to properly sequence the bias applied to an RF/microwave GaAs FET or a MMIC (monolithic-microwave-IC ] amplifier. These devices are extremely sensitive to drain and gate voltage levels as well as to the order in which these biases turn on and off. A GaAs-FET amplifier that uses two bias voltages-a negative supply, VGG, on its gate and a positive supply, VDD, on its dra Design by Tom Roberts, Anritsu Co, Morgan Hill, CA
Circuit Improves Transient Dynamics - 06/24/99 EDN Design Ideas: Designing low-voltage, high-current converters with fast dynamic performance places stringent demands on a system designer. However, a simple technique reduces the peak voltage deviation and decreases the response time for a tran Design by Robert Sheehan, Linear Technology Corp, Milpitas, CA
Circuit limits DV/DTand Capacitor inrush at Regulator Turn On - 10/11/07 EDN Design Ideas: Adding a simple circuit to the adjust pin of a regulator controls the dV/dt of the output voltage, limiting inrush current Design by W Stephen Woodward, Chapel Hill, NC
Circuit Measures Small Current in DC Servo Motor - 12/06/01 EDN Design Ideas: The simple Circuit design in Figure 1 lets you measure all components of a current flowing in a dc servo motor. The rectified output of the circuit uses ground as a reference, so you can measure the output by using a single-ended A/D converter. The current-sense resistor, R1, has a value of 0.1Ω Design by Shyam Tiwari
Circuit provides ADSL frequency reference - 05/25/00 EDN Design Ideas: The discrete-multitone (DMT) frequencies that asymmetrical-digital-subscriber lines (ADSL) use are integral multiples of a common frequency, and the symbol period is the inverse of this frequency. integration over the symbol period allows the sine and cosine orthogonal waveform products to vanish for all multiples of the common frequency except for those having the same frequency. Design by Bert Erickson, Fayetteville, NY - May 25, 2000
Circuit Provides Leading-Edge Blanking - 29-May-03 EDN Design Ideas: in isolated switch-mode power supplies using peak-current-mode control, generally the current-sense resistor senses the current on the primary side of the power converter. Figure 1 shows a typical circuit, in which R2 is the current-sense resistor that monitors the current. The current-sense signal goes to the input of the PWM comparator—in this case, the PWM comparator's input (iSENS Design by Michael O'Loughlin, Texas Instruments, Dallas, TX
Circuit provides reference for multiple ADCs - 24-Jan-02 EDN Design Ideas: The achievable accuracy for systems with multiple ADCs depends directly on the reference voltages applied to the ADCs. Medical-ultrasound-imaging systems, for example, commonly include a large number of ADCs in the system's beam-former electronics, with the ADCs usually organized in groups of 16, 24, 32, and so on Design by Ron Gatzke and Tanja Hofner, Maxim Integrated Products, Sunnyvale, CA
Circuit Secures Bootstrap Operation Under Light Load - 05/12/11 EDN Design Ideas: Additional circuit lets a capacitor charge, preventing voltage dips. A previous Design idea highlights a potential issue of a bootstrap IC under light-load or precharged load operation (Reference 1). The circuit in Figure 1, with the additional circuit in the green box, fixes the problem of a voltage dip in the bus-voltage signal. The waveforms in Figure 2 demonstrate how this problem takes place in buck converter IC 1B when its output voltage, VBUS, dips below the regulation point at a fixed rate under no load. By inspecting the other traces in Figure 2, you can conclude that the dip of VBUS occurs Design by Chee Hua How
Circuit Serves as Milliohm Meter - 04/15/04 EDN Design Ideas: When I was recently debugging a design, I discovered that a short circuit existed from a ground plane to a power plane. I did not have access to a milliohm meter or an equivalent tester for locating this type of short circuit. So, I logged onto the internet to find an easily constructible milliohm meter Design by AM Hunt, Lancaster Hunt Systems Ltd, Shepperton, UK
Circuit translates I2C voltages - 12/26/02 EDN Design Ideas: This design idea explores level-shifting an i˛C bus from 5V/ground (positive domain] to ground/25V (negative domain]. in multi-supply systems, you sometimes face a situation in which digital information stored in logic circuits running from 5V to ground needs conversion to analog signals referenced to a negative supply Design by Peter Liu, Optron X, Allentown, PA
Circuit Uses Two Reference Voltages to Improve Hysteresis Accuracy - 7-Jan-10 EDN Design Ideas: increase the hysteresis of your comparator by switching between two reference voltages Design by Marián Stofka, Slovak University of Technology, Bratislava, Slovakia
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