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µC squares input signal - 12/19/96 EDN-Design Ideas....Converting a
random-width pulse to a signal with the same frequency but with a 50% duty cycle isn't
easy, especially when the specified frequency range is large…. [Design Idea by
Yongping Xia, Philips Lighting Electronics Co, Torrance, CA] |
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200MHz-400MHz Voltage Controlled Oscillator (VCO) - If you need a clean
emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works
fine. It uses four voltage-controlled capacitors to change the frequency.... [Designed
by David A. Johnson] |
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AF Generator - My generator can produce sine- and squarewaves with
frequencies between 1 Hz and 100 kHz and amplitudes ranging from zero to 1.55 Veff in
600 Ohms. Sinewave distortion is 0.1% or less between 20 Hz and 20 kHz, somewhat
greater outside this region. The output voltage …(electroninc design added 04/05/06)
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An OscillatorSawtooth & Square Wave Output - SimpleSingle Supply and Works
Very well with Minimum Parts Count....(Circuit design added 12/08) |
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CMOS Iinverter Parallel LC Oscillator - I have used this parallel resonant
LC oscillator circuit countless times. The oscillator frequency is determined by
the inductor and capacitor values. I have shown an adjustable inductor to make
it easy to set the frequency to a specific value. Once set the frequency is
fairly stable over supply voltage variations and temperature changes. The values
shown are for 125KHz but the frequency can range from tens of kilohertz to tens of
megahertz. With a 74HCU04 type inverter, it will oscillate down to about
1.5 volts. If the frequency is low, you can also use a 74C04 (CD4069) inverter.
…. [Designed by David A. Johnson] |
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CMOS Inverter 125kHz LC Oscillator - This circuit uses a single CMOS
inverter to form a series resonant LD oscillator. The values shown set the
oscillation at about 125KHz buth other frequencies are possible by changing the main
LC values.... [Designed by David A. Johnson] |
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CMOS Inverters Form 125kHz Oscillator - This circuit is similar to schematic
CMOS INVERTER 125KHz LC OSCILLATOR but inverts the LC components so the inductor is
grounded. Two inverters are needed to produce the needed oscillation.
Again, the values shown set the frequency at 125KHz but can be changed to produce
other frequencies.... [Designed by David A. Johnson] |
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CMOS Nand Gate Forms Gated 125kHz Oscillator - This circuit is similar to
schematic number 116 but uses a NAND gate as an inverter. The gate allows the
oscillator to be gated on and off. Again, the values shown set the frequency at
125KHz but can be changed to produce other frequencies.... [Designed by David A.
Johnson] |
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CMOS Schmitt Trigger IC Makes VCO - By changing the supply voltage fed to a
classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed
over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to
maintain a constant TTL logic level signal.... [Designed by David A. Johnson] |
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Convert periodic waveforms to square-waves - 16-Aug-01 Issue of EDN
Converting periodic waveforms to square waves is an integral part of extracting a
clock signal from data, creating waveform generators, and making timing-pulse
generators. Any square-wave-conversion circuit isvaluable when the square wave's duty
cycle is variable and controllable. Figure 1 shows a circuit that has these attributes
and can drive several TTL-compatible loads.... [Design Idea by Ron Mancini, Texas
Instruments, Bushnell, FL] |
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