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Its contribution to total noise is characterized by the corner frequency f c between the low-frequency region dominated by flicker noise and the higher-frequency region dominated by the flat spectrum of white noise. MOSFETs have a high f c (can be in the GHz range). JFETs and BJTs have a lower f c around 1 kHz, [3] but JFETs usually exhibit ...
The flicker of a CRT monitor can cause various symptoms in those sensitive to it such as eye strain, headaches [9] in migraine sufferers, and seizures in epileptics. [10]As the flicker is most clearly seen at the edge of our vision there is no obvious risk in using a CRT, but prolonged use can cause a sort of retinal shock where the flickering is seen even when looking away from the monitor.
Does not normally occur due to a high refresh rate higher than FPS [25] Does not normally occur at 100% brightness level. At levels below 100% flicker often occurs with frequencies between 60 and 255 Hz, since often pulse-width modulation is used to dim OLED screens. [26] [27] Risk of image persistence or burn-in: High [28] Low [28] High [28 ...
TV, computer monitor, radar display, oscilloscope: Yes Direct view Charactron CRT: Spherical curve 24 61 Computer monitor, radar display: No CRT self-contained rear-projection Flat lenticular: 80 [4] 203 TV: Yes CRT front projection: Flat (limited only by brightness) TV or presentation No Plasma display: Flat 152 [5] 386 TV, computer monitor
Spectrum analyzer based measurement can show the phase-noise power over many decades of frequency; e.g., 1 Hz to 10 MHz. The slope with offset frequency in various offset frequency regions can provide clues as to the source of the noise; e.g., low frequency flicker noise decreasing at 30 dB per decade (= 9 dB per octave). [3]
High resolution monochrome mode using a custom non-interlaced monitor with the slightly lower vertical resolution (in order to be an integer multiple of low and medium resolution and thus utilize the same amount of RAM for the framebuffer) allowing a "flicker free" 71.25 Hz refresh rate, higher even than the highest refresh rate provided by VGA.
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15. [2]A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).
If used correctly, the Leeson equation gives a useful prediction of oscillator performance in this range. If a value for f c is included, the equation also shows a curve fit for the flicker noise. The f c for an amplifier depends on the actual configuration used, because radio-frequency and low-frequency negative feedback can have an effect on f c.