Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltage and to ensure a constant difference between the input and the output voltages (Figure 1). This circuit is useful for high-side-drive applicati…

Driving LEDs at a regulated current from low supply voltages can be difficult because minimal overhead voltage is available for control circuits. A current-mirror architecture is suitable but usually works only with ICs with well-matched transistors…

A previous Design Idea describes a programmable current source that used a three-terminal National Semiconductor LM317 adjustable regulator (Reference 1). Although that circuit lets you program the output current, the load current flowed through the…

Cs5171: Tracking Boost Regulator Adding a current mirror circuit to a typical boost circuit allows the user to select the amount of boost voltage and ensure a constant difference between input and output voltage.   This is useful for high side drive…

http://learn.adafruit.com/ice-tube-clock-kit/design Tubes such as VFDs, Nixies, Decatrons, etc require high voltage to light the gas in the tube. For nixies, this iabout 170VDC. VFDs aren't as bad they only need about 30-50VDC. In order to reduce cos…

LDO Regulator High accuracy voltage regulator Vout = 2.5V * (1 + ( 5.6 / 6.8 ) ) = 4.55V Recently the author had to adapt  a standard circuit configuration  (which often uses an npn bipolar) so as to operate as a low-dropout (LDO) regulator. The circ…

LDO current regulator for power LED Challenge You've got a power LED? Great! Build a flash light! What does the spec say? "Voltage: 3.6 .. 3.8 V, power 3 W." Okay. This means that it draws some 800 mA. Three mignon cells give 4.5 V for at least…

High accuracy voltage regulator Good morning everybody, I want to make a accurate voltage regulator based on the Basic Stamp.Total range 0-10 V and a resolution of eg 5 mV. So this means 2000 steps.Maximum current around 250 mA. I tried to do somethi…

http://pdfserv.maximintegrated.com/en/an/AN818.pdf http://www.maximintegrated.com/app-notes/index.mvp/id/818 Digital Adjustment of DC-DC Converter Output Voltage in Portable Applications Abstract: This tutorial discusses methods for digitally adjusti…

Most isolated, offline SMPSs (switched-mode power supplies), including flyback, forward, and resonant, must operate at input voltages of 90 to 260V rms. Some cases even use line-to-line voltages of 400V rms±10%, leading to increased component-voltage…