High stability frequency synthesis frequency signal generator
L loop low-pass filter and DC amplifier to be applied. Four BCD preset code from 9 to 24 feet into. BCD can be used to manually dial the number of code disc set [shown as decimal engraved show], active HIGH. Can be easily input by the microcontroller 16-bit binary data parallel program-controlled. Is the power of 3 feet. 2 feet grounded in the 8 V supply voltage when its highest crossover frequency rate 80MHz. 28 feet for the lock indicator output signal ID, the loop is locked outside of normal working 28 feet high, the access LED light. Figure 3 decimal-based high-frequency phase-locked loop frequency synthesizer circuit of electronic measurement of total 2005 second period 11 map (Omitted high-frequency power amplifier and power supply circuit). The system uses the MC1648 VCO as Ic, the highest oscillation frequency up to 225MHz. The use of relatively simple, using a pair of back to back varactor diodes for voltage-controlled frequency adjustment is to increase the output frequency linear control. Cover design band. The actual circuit used in the oscillation coil section access, through the electronic switch for automatic switching (digital logic circuits can be programmed by switching automatically generated to determine the band switching signal, this is abbreviated), while the low-pass filter output of about 0-4 Vdc single voltage power operational amplifier IM358 be enlarged to O-13 DC volts to increase the varactor capacitance range. These two measures with LED allows full-frequency coverage factor greater than 3.5 times. If the required output FM signal can be modulated from Vmodin end by adding audio signals, potentiometer signal determines the location and size of FM deviation, so the system easily can be used as FM radio frequency signal source. As the MC145163 is less than the maximum crossover frequency 80MHz, so the VCO output frequency signal must be pre-high-speed prescaler divider. This step requires taking into account the restrictions, using only one of the two divided parts, the design phase frequency 5kHz, fixed high-speed divide just after the interval to make the output frequency 10kHz, and the programmable divider to set the number of decimal and decimal output matching. Figure 3 PLL frequency synthesizer frequency decimal figure of the total high-frequency PLL frequency synthesizer As a result of large scale integrated circuits, circuit composition and overall design becomes very simple loop parameters, the main consideration two points, The first phase frequency, the second is the loop filter. As selected with four BCD / N programmable divider which allows for a maximum input frequency 80MHz, and therefore make full use of its internal divider to achieve the minimum output frequency to ask every of 10kHz, as had after the introduction of the VCO of a high-speed fixed two divider, the output frequency to every question to 10kHz, the design must take the phase frequency of 5kHz. This can be by setting the MC145163 internal reference frequency divider allows the phase frequency of 5kHz. In the PLL loop low-pass filter design is very important, it affects the performance of the loop when asked about the machine,
Beats By Dre Headphones, such as capture the signal to noise ratio. If the low-pass filter time constant large, cut-off frequency is low,
Beats By Dre Studio, the output signal to noise ratio is high, the spectrum of pure, but to capture the lock ring into a long time, the need for fast channel frequency conversion applications should be designed to use low-pass filter some of the higher cutoff frequency. For the system as a general design considerations for high-frequency equipment or FM radio signal source used, the capture time is not critical, and because the requirement to carry out high-frequency FM, it is low-pass filter cutoff frequency should be made lower (where the design fetch less than 10Hz). Proportional-integral circuit with passive low-pass filter (see Figure 3, composed by the R1.R2.C1) simple structure, stable performance, convenient debugging. Figure 3 Output frequency preset by four BCD DIP switches to achieve,
Salvatore Ferragamo outlet, the use of single-chip MC145163 parallel program-controlled, but can increase the functionality,
herve leger sale, for example,
tods shoes outlet, direct display output frequency, output frequency can be multiple storage and retrieval and easier to use, intuitive. The high-frequency PLL frequency synthesizer integrated circuit design all the components, in particular selected MC145163p lock circuit block, the output frequency can achieve a convenient and intuitive way to change the decimal, and the minimum frequency interval to 10kHz, thanks high-frequency integrated voltage-controlled oscillator, the phase-locked high-frequency high frequency frequency synthesizer output frequency range from 29.00MHz to 99.99MHz. Frequency to seven thousand, frequency stability better than ± 5ppm, for equal amplitude sine wave, but also for the FM waves, expanding the range of applications. References 1 [U.S.] Weidi Mu.迈纳赛维奇 frequency synthesizer Beijing: Mechanical Industry Press, 1992.6
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