1 Watt PLL FM Broadcast Transmitter-  This is a 1 Watt PLL FM broadcast transmitter.  The RF output varies from 500mW to about 1.2W depending on the frequency selected and RF output transistor used.  Motorola 2N4427 always seems to work well.  Transmitter uses CMOS PLL VCO that prevents the frequency drifts.  The frequency is selected via DIP switches.  The transmitter is supplied by 12V DC and can also be powered from the battery.__

1.5 GHz PLL Frequency Synthesizer-  In order to obtain excellent phase stability between two beams in our experiment, it is preferable to derive them from the same laser.  This is a limitation however, if the beams operate at different frequencies.  For frequency differences of less than a few hundred MHz, the approach is to split the beam and send it through an AOM.  For higher frequencies, we employ an optical phase-locked loop (OPLL) in which the beat frequency between two lasers sent to a feedback loop and locked to a given separation.  __

1W Portable PLL transmitter-  This small FM transmitter includes a limiter, a microphone amplifier and a PLL digital tuning.  All the parts are placed on one circuit board.  The RF power is switchable between 1W and 0, 2W __ Jan Kolar

2 gates & a microprocessor form digital PLL-  04/14/05 EDN Design Ideas:  Low-frequency PLL needs just a processor and gates Design by Kenneth Martin, TareTronics Inc, Corinth, MS

500mW PLL FM Transmitter 88-108MHz-  This PLL transmitter is controlled and the frequency is very stable and can be programmed digitally.  Transmitter will work 88-108 MHz and output power up to 500mW.  With a small change can set the frequency of 50-150 MHz.  The output power is often set to several watts with transistors.  So therefore I decided to build a simple transmitter with great performances.  The frequency of this transmitter can easily be changed by software and space / compress air coil.  This transmitter is the oscillator Colpitts.  Oscillator is a VCO (voltage controlled oscillator) which is set by the PLL circuit and PIC micro controller.  This oscillator is called the Colpitts oscillator and voltage controlled to achieve the FM (frequency modulation) and PLL control.__

50mW BH1417 Stereo PLL FM Transmitter-  This is an excellent 50mW Hi-Fi PLL FM Stereo Transmitter that features BH1417 chip.  ROHM's new Japan has BH1417 is one of the most simple and practical integrated circuits, which combines phase-locked loop circuit, stereo encoder circuit, transmitter circuit, as well as other additions.  Pre-emphasis circuit, limiter circuit and low pass filter can significantly improve the sound quality.  The total harmonic distortion up 0.3%, stereo separation to 40dB, RF output level is 100dB.  BH1417F is an excellent new IC chip, this circuit improves signal to noise ratio (S / N) of pre-emphasis circuit to prevent signal over emphasized limiting circuit, the control input signal frequency low-pass filter circuit (LPF) , generate stereo stereo composite signal modulation circuit, FM transmitter phase-locked loop circuit (PLL) component.  BH1417F excellent frequency characteristics, it can achieve 40dB of isolation, transmitted sound quality is similar to local FM radio stations.__

8 Watt TX PLL with LCD-  (TSA5511, PIC16F84, 4MHz Crystal) __

8W PLL Stereo Transmitter with LCD-  Very stable FM transmitter based on TSA5511 synthesizer.  Frequency is performed with three buttons through PIC16F84 microcontroller.  Frequency is displayed on 16x1 LCD. __

Add a door-chime repeater-  05/13/99 EDN Design Ideas:  Electromechanical door chimes can enhance your home, but they are vulnerable to costly repair problems.  A defective pushbutton switch or a careless visitor can maintain the chime in an energized state for a prolonged period, thereby damaging the chime.  The circuit in Figure 1 prevents damage to the chime and improves the chime's effectiveness by repeating the chime strike for as long as the pushbutton remains depressed.  The circuit controls both front and rear chimes.  The heart of the circuit is timer IC2, which you configure as an astable multivibrator.  The timing components, R1, R2, R3, and C3, provide the required pulse widths. Design by Dennis Eichenberg, Parma Heights, OH

AN-95-006  Optimizing VCO/PLL Evaluations & PLL Synthesizer Designs-  AN-95-006 Application Note__ MiniCircuits.com

Audio noise generator drives earphones or small speaker -  This is a circuit that generates white noise, rolled-off to drive earphones or a small speaker.  White noise creates is a "rushing" sound, which sounds something like air rushing by your ear (s).  White noise would be flat with frequency, and since this circuit rolls off within the audio range, I refer to it as "rolled-off" noise.  White (or rolled-off) noise __ Designed by Dick Cappels

AVR ATMega8 board for PLL MC145170-  This board allow to manage a FM transmitter including a Phase Locked Loop (PLL) on a serial bus (SPI) like a MC145170.  A current frequency is memorized in EEPROM to configure PLL at power up.  Three auxiliary frequencies are available for maintenance function and/or HF adjust.  A local interface include 4 keys and a LCD display enable to modify transmitter parameters.  This board can be completely derived from a serial link RS232 (19200 Bds, 8b data, 2b stop, no parity).  A temperature sensor enable to control working temperature and 2 analog input are used for HF power measure (Forward and Reflected).  Information about TOS protection activation is processed by this board to inform user (local and remote) on a TOS Alarm. __

Barker Code-Locked Loop Synchronous Demodulator-  A simple, low component count phase locked loop that locks onto and detects the amplitude of an incoming base band 7 bit Barker code using a switched resistor demodulator that is driven directly by a microcontroller's output pins __ Designed by Dick Cappels

BH1417 PLL Stereo Transmitter-  This is the latest BH1417 FM Transmitter design from RHOM that includes a lot of features in one small package.  It comes with pre-emphasis, limiter, stereo encoder, low pass filter, PLL rock solid frequency transmission and RF output buffer.__

BH1417 Stereo PLL FM Transmitter-  The new FM Stereo Micromitter is now crystal-locked which means that the unit does not drift off frequency over time.  In addition, the distortion, stereo separation, signal-to-noise ratio and stereo locking are much improved on this new unit compared to the earlier designs.  The specifications panel has further details__ SiliconChip

BIAS COMS PLL transmitter-  This schematic originally comes from Bias Comms and was originally intended for use in combination with a BGY33 or BGY133 module.  The PLL is very straightforward and should not be too difficult to build. __

Build a Digital PLL with Three ICs-  05/10/12  EDN Design Ideas:  A counter’s self-presetting feedback loop hunts for the center count. Design by Dave Allen, Dash Inc, Kansas City, KS

Capacitance Meter Uses PLL for High Accuracy-  8-Oct-09 EDN Design Ideas:  An improvement on an old design lets you measure capacitors from 10 pF to 1 µF Design by Jim McLucas, Broomfield, CO

Clock multiplier circumvents PLL-  05/13/99 EDN Design Ideas:  Using a standard PLL circuit, such as the CMOS 4046B with some passive components, is a well-known way to design a clock multiplier Design by Jose Carlos Cossio, Santander, Spain

Clock Recovery PLL Fits into Single PLD-  11/23/95 EDN Design Ideas:  Serial-communication ICs can save you from using an extra wire thanks to an internal PLL clock-recovery circuit that reconstructs a clock signal phase-locked to the serial data stream. Design by Ricardo Monleone, AGIE Ltd, Losone, Switzerland

CMOS RF PLL Synthesizer-  Synthesizer based on available CD4059.  CD4046 and CD4060 ICs. __ Designed by Harry Lythall-SM0VPO

DC Accurate Filter Eases PLL Design-  DN7 Design Notes__ Linear Technology/Analog Devices

Fix Adds Door Chime Repeater-  05/13/99 EDN Design Ideas:  Electromechanical door chimes can enhance your home, but they are vulnerable to costly repair problems.  A defective pushbutton switch or a careless visitor can maintain the chime in an energized state for a prolonged period, thereby damaging the chime.  The circuit in Figure 1 prevents damage to the chime and improves the chime's effectiveness by repeating the chime strike for as long as the pushbutton remains depressed.  The circuit controls both front and rear chimes.  The heart of the circuit is timer IC2, which you configure as an astable multivibrator.  The timing components, R1, R2, R3, and C3, provide the required pulse widths. Design by Dennis Eichenberg, Parma Heights, OH

FM Synthesizer N°1-  In order to simplify the transmitter design, we've used the new pll circuit from Motorola :the MC145170.  This PLL includes the prescaler and a serial standard bus called SPI. __ Designed by Michel P

FM Synthesizer N°2-  This new FM transmitter is very simple and doesn't need any RF tuning.  First of all , we have used an integrated VCO: The POS150 from Mini-circuits.  This excellent RF circuit covers all the FM Band in a voltage range of 4V to 8V.  The Kvco factor is very stable all over the FM band, (08/08/08) __ Designed by Michel P

Improved CMOS RF PLL Synthesizer-  Lock range extended up to about 400:1 (50KHz, 2MHz).  Spectral purity improved, reduced reference frequency FM ripple.  Output level buffered to over 200mW RF power output.  Unnecessary DIP switches removed, silly combinations not possible.  BMP format single-sided PCB foil available for downloading.  External VCO/Prescaler PCB to follow shortly (up to 150MHz) __ Designed by Harry Lythall-SM0VPO

Low-Cost RF Synthesizer Uses Generic ICs-  24-Jun-10 EDN Design Ideas:  You can design a hardware-based frequency synthesizer with one inexpensive IC and a few passive components.  Such synthesizer chips are not always available, however, because they are typically single-sourced and are not in stock with parts distributors.  The need for a working circuit in a short time and using common parts prompted the creation of the circuit in this Design Idea.  The synthesizer covers the US commercial AM (amplitude-modulation) broadcast band.  It tunes in 10-kHz steps from 500 to 1800 kHz, but you can scale the frequencies for other applications Design by James B Wood, Inovonics Inc, Felton, CA

Low-cost, programmable oscillator operates at 2 GHz-  05/11/00 EDN Design Ideas:  All wireless communication systems need a local oscillator.  Figure 1 shows a low-cost PLL circuit for the 2-GHz band for such applications as industrial, scientific, and medical (ISM]and satellite personal-communication systems (S- Design by A Navarro, M Rostami, and JN Matos, Instituto de Telecomunicaçoes, Aveiro University, Portugal

LTC1436-PLL Low Noise Switching Regulator Helps Control EMI-  DN141 Design Notes__ Linear Technology/Analog Devices

MC145151 PLL FM Transmitter-  This PLL has been designed with an old Motorola circuit :the MC145151.  The VCO is based on a "Colpitts" oscillator equipped with a FET Transistor. (J310) Two varicap Diodes are used in order to reduce the global noise of the VCO.  In addition, these two diodes allow the PLL to keep the lock status through a large range of climatic conditions.  An another J310 is used in order to match the impedance between the oscillator and the fist amplifier stage.  A MSA1105 from Minicircuits increases the RF power level coming from the VCO to +14dBm.  A simple low pass filter rejects the second harmonic to -20 dB. (Worst case) Finally, a 7 dB attenuator and a second amplifier stage (BFR96S) achieve this radio design. __ Designed by Michel P

MC145170 PLL FM transmitter-  This new FM transmitter is very simple and doesn't need any RF tuning.  First of all , we have used an integrated VCO: The POS150 from Mini-circuits.  This excellent RF circuit covers all the FM Band in a voltage range of 4V to 8V.  The Kvco factor is very stable all over the FM band, (08/08/08) __ Designed by Michel P

Micro Spy PLL FM Transmitter-  This micro spy PLL FM Transmitter transmits on the 160MHz frequency (if we use a 40MHz quartz) and therefore can be listened through a receiver tuned on this frequency.  This circuit can be used to on various frequencies, for example on the FM band 88-108 just modifying some components, among which the quartz (25MHz).  Voice is detected by an electret microphone, then it is amplified and filtered by U1 pass-band in order then to be modulated from the carrier section, where through the varicap diode it "mixes" with the frequency generated by the quartz, that guarantees an adapted stability.  Practically the modulating voltage is obtained applying the audio signal to the resonating circuit varicap diode that determines the carrier oscillation.  The carrier frequency (160 MHz) must be greater than the modulating frequency (300-3300 Hz) audio band.  The transmission is on the fourth harmonic, therefore 160MHz, the oscillation frequency of the driver RF transistor Q1.  A small calibration is allowed acting on the L1 inductance and the C1 Trimmer Capacitor.__

Optimizing VCO/PLL Evaluations & PLL Synthesizer Designs-  AN-95-006 Application Note__ MiniCircuits.com

PLL's:   #'s - O       P - Z