Crystal Oscillator Circuits
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The oscillator delivers an output of high spectral purity without any substantial sacrifice of the usual stability of a crystal oscillator. The crystal in addition to determining the oscillator's frequency, is used also as a low-pass filter for the unwanted....
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CI in series with the crystal may be used to adjust the oscillator output frequency· Value may range between 20 pF and 0.01 µ¥, or may be a trimmer capacitor and will approximately equal the crystal load capacitance. X values are approximate and can vary....
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One section of the MC10101 is connected as a 100 MHz crystal oscillator with the crystal in series with the feedback loop. The LC tank circuit tunes the 100 MHz harmonic of the crystal and may be used to calibrate the circuit to the exact frequency. A second....
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This circuit employs an adjustable resonant tank circuit which insures operation at the desired crystal overtone. Cl and LI form the resonant tank circuit, which with the values specified as a resonant frequency adjustable from approximately 50 MHz to 100....
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The crystal element in this circuit is connected directly between the base and ground. Capacitor Cl is used to improve the feedback due to the internal capacitances of the transistor. This capacitor should be mounted as close as possible to the case of the....
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The crystal is in a feedback circuit from collector to base. A trimmer capacitor in series shifts the point on the reactance curve where the crystal operates, thus providing a frequency trim..
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The crystal operates into a complex load at series resonance. Ll, Cl, and C2 balance the crystal at zero reactance. Capacitor Cl fine-tunes the center frequency..
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This circuit is often used by amateur radio operations, shortwave listeners, and other operators of shortwave receivers to calibrate the dial pointer. The oscillator operates at a fundamental frequency of 100 kHz, and the harmonics are used to locate points....
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The crystal is placed between the collector of the output stage and the base of the input stage. The frequency of oscillation can be set to a precise value with trimmer capacitor CI. The range of operation for this circuit is 500 kHz to 10 MHz..
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For frequencies below 20 MHz, a fundamental-frequency crystal can be used and the resonant tank is no longer required. Also, at this lower frequency range the typical MECL 10,000 propagation delay of 2 ns becomes small compared to the period of....
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This low cost, crystal-controlled oscillator uses one TTL gate. Two factors ensure oscillator start-up: The connection of NAND gates G1, G2, and G3 into an unstable logic configuration and the high loop gain of the three inverters. Values of R1, R2, C1,....
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An on-board oscillator and a 17-stage divider compose IC1. By connecting a standard 3.58-MHz, television color-burst crystal as shown, an accurate source of 60-Hz squarewaves is generated at the IC"s output, pin 1. Those pulses are then fed to IC2, a 4024....
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This unit is easily tunable and stable, consumes little power, and costs less than other types of oscillators tlmt operate at the same frequencies. This unusual combination of features is made possible by a design concept that includes operation of the....
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This circuit uses LTC1043 to differentiate between a temperature sensing network and a de reference. The single-ended output biases a varactor-tuned crystal oscillator to compensate drift. ..
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Diagram shows a 100MHz oscillator operating on the fifth harmonic. Again to maintain the transistor"s gain, note the increase in the collector"s load resistance Rl because of the increase in the quartz crystal"s internal series resistance R5. C3 is needed....
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Diagram shows a 50MHz oscillator operating on a third harmonic. The collector"s load resistor R1 has been increased because the quartz crystal"s internal series resistance Rs increases with frequency in the VHF range. The crystal"s internal series....
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Although ceramic resonators are a good choice for low-power, low-frequency clock sources (if you can stand their 30-ppm te..
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CI capacitor in series with the crystal may be used to adjust the output frequency of the oscillator. The valu..
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This simple circuit will oscillate with a wide range of crystals. Connect several different types of crystal holders in ..
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Ql, Q2, and the associated circuitry form a modified astable multivibrator in which the loop gain is automatically adjusted to the threshold of oscillation by means of field effect transistor Q3. Q4 linearly amplifies the signal present at the collector of....
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On occasion, microprocessors/microcomputers and microprocessor crystals just aren`t compatible with each other. Many microprocessor data sheets specify maximum values for a crystal`s equivalent series resistance (Rs) that aren`t met by some crystals....
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This general purpose signal source serves very well in signal-tracing applications. The output level is variable to more than 1 Vrms into a 50 O load. Almost any crystal in the 1 to 15 MHz range can be used. Ql forms a Colpitis oscillator with the output....
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A high speed oscillator is possible by combining an MECL 10 crystal oscillator with an MECL III frequency doubler as shown. One section of the MC10101 is connected as a 100 MHz crystal oscillator with the crystal in series with the feedback loop. The LC....
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The FET input amplifier has fixed bias with source feedback. This provides a very high input impedance with very low capacitance. The FET amplifier drives an emitter follower which, in spite of the fact that it has a low output impedance, feeds a transformer....
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Resistors Rl and R2 temperature-stabilize the NAND gates; they also ensure that the gates are in a linear region for starting. Capacitor CI is a dc block; it must have less than Vw ohm impedance at the operating frequency. The crystal runs in a....
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The circuit is powered by a single 1.35 V mercury cell and provides a 1 V square-wave output. As shown, the crystal is a tuned circuit between transistors Ql and Q2, which are connected in the common-emitter configuration. Positive feedback provided by means....
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By a crystal oscillator b DTL integrated circuit constituted DTL is shown by the crystal oscillator integrated circuits, and the oscillation frequency..
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It consists of several gates as a crystal oscillator circuit c Several gates as shown by a crystal oscillator circuit. FIG. (A) to l MHz crystal oscillator circuit, the figure (b) is 20 MHz crystal..
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Temperature stable resistors R1 and R2 NAND gates, they ensure that the switches in the linear region open. Capacitor C1 is a DC component at the operating frequencies, ..
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One of the nicest features of the 8-bit KX8 microcontroller (manufactured by Freescale Semiconductor) is that it includes an internal clock generator (ICG). This allows the chip to run without the trouble and expense of an external crystal or canned....
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Bugdozer is an autonomous mini-Sumo robot. Her main board consists of a MC68HC908GP32 microcontroller along with input/output support chips, a voltage regulator, a crystal oscillator, and the usual assortment of resistors, capacitors, and switches. All chips....
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The world is full of xtal oscillators twiddled by digital designers lacking in the analog design knowledge necessary. Just look at all the PC real time clocks that lags or leads by several minutes per day. And they eat backup batteries too! IC`s with pins....