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Ultra Low Voltage Nanopower Two-Input NOR & NAND Gates - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc Ultra Low Voltage N-Channel Analog Switch Transmission Gate - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc
Ultra Low Voltage RC Oscillator - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc
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 Boost Regulator Beyond Its Rated Voltage - 01/05/12 EDN-Design Ideas Use an external FET in a common-gate cascode configuration. Inexpensive boost regulators with on-chip FET power switches work well for low-voltage boost converters, SEPICs (single-ended primary-inductance converters) , and flyback converters. For higher voltages, designers typically use a more expensive approach comprising a controller with an external FET or a high-voltage boost regulator. Design by Kevin Tompsett, Analog Devices, Fort Collins, CO
Use a Photoelectric-FET Optocoupler as a Linear Voltage-Controlled Potentiometer - 01/19/12 EDN-Design Ideas The circuit takes advantage of an identical photo-FET as a feedback element. You can use a photoelectric FET as a variable resistor or a potentiometer in combination with a fixed resistor. The H11F3M photoelectric FET has an isolation voltage of 7.5 kV, enabling you to safely control highvoltage circuit parameters. The nonlinear-transfer characteristics of these devices are problematic, however (Figure 1) . To correct the nonlinearity, using a simple feedback mechanism as a potentiometer yields a linear response (Figure 2) . This circuit uses two photoelectric FETs—one for feedback and the other for applications requiring an isolated potentiometer. You connect the inputs of the two photoelectric FETs in series to ensure the same amount of current for the input LEDs. Design by Sajjad Haidar, University of British Columbia, Vancouver, BC, Canada
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 Bob Zwicker, Analog Devices, Fort Collins, CO
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
Voltage Controlled Resistor - Circuit Ideas for Designers App Note__ Advanced Linear Devices, Inc |
