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Circuit Reduces VCC Ripple in Audio Band - 01/18/96 EDN-Design Ideas - The circuit in Figure 1 reduces noise and ripple by at least 35 dB over the audio range of 100 Hz to 20 kHz. The circuit provIdeas a clean source of 5V power for driving audio circuits in portable applications such as cellular phones and multimedia notebook computers. Most linear regulators reject noise only to about 100 Hz, Design by John Wettroth, Maxim Integrated Products, Sunnyvale, CA Digital Noise Generator - This circuit produces a repeating sequence of serial data that contains attributes useful for emulating audible noise. Upon power application, the momentary application of a "high" logic level is applied, via C1 and R1, to the RESET inputs of four four-bit shift registers, U3A, U3B, U4A, and U4B. These shift-register sections are serial-connected to form a single 16-bit register. The reset application causes the initial output states of the registers to be "low. " __ Designed by Arthur Harrison |
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Eliminate Hum from Pulsed Signal - 01/20/94 EDN-Design Ideas - The circuit eliminates hum from a periodic signal by a factor of as much as100:1. Fig2a shows an incoming signal that combines a periodic square wave and a much lower frequency hum. Suppose for simplicitys sake that the hum is sinusoidal Design by Stanislav Tomek, Slovak Technical University, Slovak Republic How to Build a Low Noise Power Supply for High Voltage (i.e.100V up to 1000V) Transducers - (Just a picture, but should be enough to build one yourself.) A Kilovolt with 100 Microvolts of Noise Photomultipliers(PMT) , avalanche photodiodes(APD) , ultrasonic transducers, capacitance microphones, radiation detectors and similar devices require high voltage, low current bias. Additionally, the high voltage must be pristinely free of noise; well under a millivolt is a common __ Linear Technology/Analog Devices App Note, Jim Williams-Staff Scientist Sep 15th 2008
Measuring Switching Regulator Noise - The universal application of switching regulators, combined with the powered systems potential for supply noise sensitivity, mandates the need for a reliable noise measurement technique. Actually, switching regulator "noise" isn't really noise at all, but coherent, high frequency residue directly related to the regulators switching. __ Linear Technology/Analog Devices App Note, Jim Williams-Staff Scientist Jun 15th 2009
Minimizing Switching Regulator Residue in Linear Regulator Outputs - Linear regulators are commonly employed to post-regulate switching regulator outputs. Benefits include improved stability, accuracy, transient response and lowered output impedance. Ideally, these performance gains would be accompanied by markedly reduced switching regulator generated ripple and spikes. In practice, all linear__ Linear Technology/Analog Devices App Note, Jim Williams Mar 21st 2011
Reduce Acoustic Noise from Capacitors - 02/17/11 EDN-Design Ideas - Adding parts or cutting PCB slots can make a difference. Some surface-mount capacitors exhibit acoustic noise when operated at frequencies in the audio range. A recent design uses 10-μF, 35V X5R 1206 ceramic capacitors that produce noticeable acoustic noise. To quiet such a board, you can use acoustically quiet capacitors from manufacturers such as Murata and Kemet. Unfortunately, they tend to cost more than standard parts. Another option is to use capacitors with a higher voltage rating Design by Damian Bonicatto, Landis+Gyr, Pequot Lakes, MN
Reduce VCC Ripple in Audio Band - 01/18/96 EDN-Design Ideas - The circuit in Figure 1reduces noise and ripple by at least 35 dB over the audio range of 100 Hz to 20 kHz. The circuit provIdeas a clean source of 5V power for driving audio circuits in portable applications such as cellular ph Design by John Wettroth, Maxim Integrated Products, Sunnyvale, CA
Royer Topology Achieves 100μVp-p Noise at 250V Output - This circuit's resonant Royer topology achieves 100μVP-P noise at 250V output by minimizing high frequency harmonic in the power drive stage. The self oscillating resonant Royer circuitry is composed of Q2, Q3, C1, T1 and L1. Current flow through L1 causes the T1, Q2, Q3, C1 circuitry to oscillate in resonant fashion, supplying __ Linear Technology/Analog Devices App Note, Apr 22nd 2011
Self-timed logic technique cuts noise & power - 06/10/99 EDN-Design Ideas - Tired of struggling with the problems of global clock timing and distribution in ASIC design? A solution to at least part of that problem may lie in a change of strategy to self-timed design. Design by Graham Prophet |
