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Frequency Divider Circuits

 Last Updated: June 02, 2021 01:45 PM

 Circuits Designed by Dave Johnson, P.E. : Circuit Forms Divide By 1.5 CounterTwo inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function. . . Circuit by David Johnson P.E.-July, 2000 Divide a TTL Clock Signal by 1.5Two inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2000 Divide By 1.5 CounterTwo inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function. . . Circuit by Dave Johnson P.E.-July, 2000

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3 GHz Divide by 1000 Prescaler -  Converts 0.1, 3 GHz freqency to 0, 3 MHz, extends frequency range measurements.   __

74ACT74 makes low-skew clock divider -  12/17/98 EDN-Design Ideas Serial-data systems often generate an internal clock at twice the data rate for mid-bit sampling or for generating bi-phase codes.  External equipment and some internal processes require a clock that runs at the data rate.  Simply dividing the twice-rate clock with a flip-flop generates a data-rate clock that is skewed by one logic delay with respect to the input.  Scroll to find this one__ Circuit Design by JTom Napier, Consultant, North Wales, PA

Amplifiers perform precision divide-by-2 -  6-Mar-03 EDN-Design Ideas Rotary encoder mates with digital potentiometerThe classic implementation of a voltage-halving circuit uses two equal-value resistors.  Using 1% resistors provIdeas a divider output with 2% accuracy.  For most applications, this performance is cost-effective andthan adequate. - Design by Glen Brisebois and Jon Munson, Linear Technology Corp, Milpitas, CA

Analog divider uses few components -  01/04/07 EDN-Design Ideas Low-cost op amp, CMOS timer perform analog math__ Circuit Design by David Cripe, Chatham, IL

Charge-pump divides by two -  02/18/99 EDN-Design Ideas NOTE :  Collection of Design Ideas, scroll to find this one.   Small size and efficiency approaching 100% make switched-capacitor charge pumps popular for voltage doubling and inverting in miniature dc-dc applications.  Few are aware, however, that most charge pumps can halve as well as double or invert an input voltage.  The increasing adoption of low-voltage logic makes this ÷2 capability useful for generating low-voltage supplies in portable equipment.  __ Circuit Design by Budge Ing, Maxim Integrated Products, Sunnyvale, CA

Circuit conditions variable-duty-cycle clock -  02/17/97 EDN-Design Ideas Simple enhancement of an earlier Design Idea("Delay line implements clock doubler",EDN, July 18, 1996, pg 102) implements a variable-duty-cycle clock-signal conditioner.  The circuit accepts an input clock of any duty cycle and generates any desired duty cycle at the output.  You need to add only one flip-flop to the earlier design to generate an arbitrary-duty-cycle output.  You can use the circuit to correct a non-50% input to a 50% output or to create a non-50% output from any arbitrary input duty cycle__ Circuit Design by David Albean, Thomson Consumer Electronics, Indianapolis, IN

Circuit divides frequency by N+1 -  07/11/02 EDN-Design Ideas Digital frequency dividers usually use flip-flop stages that connect the Q pin to the D data-input pin of the following stage.  This configuration creates a binary waveform that you can feed back to the input.  You can divide any integer lower than 2N with minimal stages, where N is the number of stages__ Circuit Design by Bert Erickson, Fayetteville, NY

Circuit divides frequency by N+5 -  07/11/02 EDN-Design Ideas Digital frequency dividers usually use flip-flop stages that connect the Q pin to the D data-input pin of the following stage.  This configuration creates a binary waveform that you can feed back to the input.  You can divide any integer lower than 2N with minimal stages, where N is the number of stages__ Circuit Design by Bert Erickson, Fayetteville, NY

Circuit Forms Divide By 1.5 Counter -  Two inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function. . . Circuit by David Johnson P.E.-July, 2000

Counter Provides Divide by 4.5 Function -  05/22/97 EDN-Design Ideas It's common practice to use a divide-by-N circuit to create a free-running clock based on another clock source.  Designing such a circuit where N is a noninteger is not as difficult as you might think.  Listing 1 gives the synthesizable VHDL code to configure a divide-by-4.5 circuit.  Figure 1 shows the simulation result for a 50-MHz input clock and a 11.11-MHz output.  You can apply the concept given here for any N, where N is 1.5, 2.5, 3.5.  First, consider what divide-by-4.5 is.  It simply means that, for every nine clocks, you need to generate two symmetrical pulses.  __ Circuit Design by Alex Sumarsono, Baynetworks Inc, San Jose, CA

Dekatron-device used for dividing by 10 during the valve era -  The circuit diagram is almost the same as Mike's.  I added an ON/OFF switch and an additional toggle switch to stop the spin.  The resistors are standard types (according to Mike I should've used higher power ones to ensure adequate voltage rating); the capacitors need to have sufficient voltage rating.  I didn't have anything rated 400V so I used two 330nF capacitors in series in two places.   __ Designed by Hans Summers

Divide a TTL Clock Signal by 1.5 -  Two inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2000

Divide By 1.5 Counter -  Two inexpensive ICs divide a TTL clock signal by 1.5.  By following the circuit with another flip/flop, you could also generate a divide by three function. . . Circuit by Dave Johnson P.E.-July, 2000

Frequency Divider Adapts to I/O Condition -  12/05/96 EDN-Design Ideas The circuit in Figure 1 accepts an input clock signal, such as from a crystal oscillator, and divIdeas the frequency according to the input divisor word.  You can easily modify the basic design of this versatile PLD-based divider to handle different I/O conditions.  The design uses the FLEX8000 family of PLDs from Altera Corp (San Jose, CA).  __ Circuit Design by Steve Hranilovic, University of Waterloo, Waterloo, ON, Canada

Frequency Dividers -  This paper is a collection of unusual frequency divider techniques which offer features not achieved with ordinary divider ICs or prescalers __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Frequency multiplier improves line readings -  EDN-Design Ideas March 26, 1998    [ NOTE : File has multiple design, scroll for this one.]  Because of the low frequencies involved, accurately measuring line-frequency variations is complicated. When you use an ordinary frequency counter with a 1-sec gate time, the reading would be 59, 60, or 61 Hz. To obtain 0.01-Hz accuracy, you must increase the gate time to 100 sec, a scale that most frequency counters do not offer.__ Circuit Design by Yongping Xia, Teldata Inc, Los Angeles, CA

Precision divide-by-two analog attenuator needs no external components -  03/17/05 EDN-Design Ideas Many modern A/D converters offer only a 5V input range, and using these converters with a 65V or larger input signal gives the designer a problem  how to discard half of a good analog signal without introducing errors and distortion.  To solve the problem, you can use an attenuator comprising two operational amplifiers and two resistors(Figure 1)__ Circuit Design by Moshe Gerstanhaber and Chau Tran, Analog Devices, Wilmington, MA

Synthesize optimal digital-frequency dividers -  05/13/99 EDN-Design Ideas For many applications, you need to divide a reference clock into one or more subclocks to use in different parts of the system.  Sometimes,PDF contains many circuits, scroll to find this one.   __ Circuit Design by Lindo St Angel, PrairieComm Inc, Arlington Heights, IL

Unusual Frequency Dividers -  This paper is a collection of unusual frequency divider techniques which offer features not achieved with ordinary divider ICs or prescalers __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Frequency Divider Circuits

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