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Digital  / Logic Circuits 
Digital Circuits:   #'s - C       D - G       H - M       N - R       S - T       U - Z

Last Updated on: Wednesday, June 02, 2021 01:44 PM

Circuits Designed by Dave Johnson, P.E.

Digital Counter using PedometerThere are many occasions when you may want to count something electronically.  Perhaps it is car traffic on a street or items moving down an assembly line.  It might be the number of times a machine is activated or maybe you want to count the number of . . . Hobby Circuit designed by David A. Johnson P.E.-August, 2008

Digital noise generator - When you need to test an audio circuit with broadband noise, this circuit works great.  It uses just three inexpensive C-MOS ICs that generate a series of output pulses whose widths vary randomly.  I included a level control pot . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000


Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

Dashboard Digital Voltmeter Project -  This project is heLPFul to anyone who drives an automobile.  I had found this project at the local libary.  in an old publication.  I made it and it worked fine.  Below are the complete text and schematic of the Dashboard Digital Voltmeter.  I re-typed the text and re-drew the schematic.  as the printing from the book was old and faded.  Sit back and read the story why this LED display might just save you from being stranded on the road! __ Designed by braincambre500 @ yahoo.com

DDR Memory Power Supply: 2.5V to 5.5Vin, 0.75V AT +/-6A Vtt, 0.75V AT 10mA Vref, 1MHz External Clock -  The LTC3617 is a high efficiency monolithic synchronous buck regulator utilizing a current mode, constant frequency architecture.  It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to 0.5 • VDDQIN while sourcing and sinking up to 6A of load current.  An internal amplifier __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 2.5V to 5.5Vin, 1.25V AT +/-6A Vtt, 1.25V AT 10mA Vref, 2.25MHz -  The LTC3617 is a high efficiency monolithic synchronous buck regulator utilizing a current mode, constant frequency architecture.  It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to 0.5 • VDDQIN while sourcing and sinking up to 6A of load current.  An internal amplifier __ Linear Technology/Analog Devices/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 3.3Vin, 0.9V AT +/-3A Vtt (with 1.8V external reference) -  Many DDR termination applications require the bus termination voltage to be stepped down from a higher system voltage while tracking one-half of a reference voltage.  This option is allowable in most systems since a reference voltage is typically available.  This circuit shows a solution for a 3.3 V to 0.9V, ±3A termination __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 3.3Vin, 0.9V AT +/-3A Vtt, 1.8V AT 3A Vddq, 0.9V AT 10mA Vref -  The LTC3618 is a dual synchronous step-down regulator using a current mode, constant-frequency architecture.  It provides a complete DDR solution with an input voltage range from 2.25V to 5.5V.  The output of the first step-down regulator offers a high accuracy VDDQ supply.  A buffered reference generates VTTR at 50% of VDDQIN __ Linear Technology/Analog Devices App Note, Aug 8th 2011

DDR Memory Power Supply: 3.3Vin, 1.5V AT +/-3A Vtt (2.5V external reference) -  The LTC3413 is a high efficiency monolithic synchronous step-down DC/DC converter utilizing a constant frequency, current mode architecture.  It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to  (0.5) VREF while sourcing or sinking up to 3A of output current.  An internal voltage __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 3.6V to 15Vin, 1.8V AT 3A Vddq, 0.9V AT +/-3A Vtt, 0.9V AT 10mA Vref -  The LTC3634 is a high efficiency, dual-channel monolithic synchronous step-down regulator which provides power supply and bus termination rails for DDR1, DDR2, and DDR3 SDRAM controllers.  The operating input voltage range is 3.6V to 15V, making it suitable for point-of-load power supply applications from a 5V or 12V input, __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 3.6V to 15Vin, VTT Powered from VDDQ -  The LTC3634 is a high efficiency, dual-channel monolithic synchronous step-down regulator which provides power supply and bus termination rails for DDR1, DDR2, and DDR3 SDRAM controllers.  The operating input voltage range is 3.6V to 15V, making it suitable for point-of-load power supply applications from a 5V or 12V input, __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 4V to 24Vin, 1.25V AT +/-10A Vtt (2.5V external reference) -  This circuit shows a ±10A design using LTC3717.  The input voltage can vary from 5V to 24V.  The input voltage can be below 5V if an external 5V bias is available for powering the VCC pin of LTC3717.  This design uses only two SO-8 PowerPak MOSFETs from Siliconix to deliver ±10A current.  To achieve a higher output current, use __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 5V to 28Vin, 1.5V AT +/-10A Vtt (3V external reference) -  The LTC3717 is a synchronous step-down switching regulator controller for double data rate  (DDR) and Quad Data Rate  (QDRTM) memory termination.  The controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor.  Operating frequency is selected by an external resistor __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR Memory Power Supply: 5Vin, 1.25V AT +/-6A Vtt (2.5V external reference) -  The LTC3831 is a high power, high efficiency switching regulator controller designed for DDR memory termination.  The LTC3831 generates an output voltage equal to 1/2 of an external supply or reference voltage.  The LTC3831 uses a synchronous switching architecture with N-channel MOSFETs.  Additionally, the chip senses output current __ Linear Technology/Analog Devices App Note, Jun 29th 2011

DDR3 1.5V VDDQ/20A 0.75VTT/±10A 4.5V to 14V Input -  The LTC3876 is a complete DDR power solution, compatible with DDR1, DDR2, DDR3 and future DDRX lower voltage standards.  The LTC3876 includes VDDQ and VTT DC/DC controllers and a precision linear VTT reference.  A differential output sense amplifier and precision internal reference combine to offer an accurate VDDQ supply.  The __ Linear Technology/Analog Devices App Note, Dec 5th 2011

DDR-differential-clock source on SOC drives two DDR-memory chips -  02/05/09  EDN-Design Ideas OC integrates controller to drive two external-DDR-memory chips without a costly differential-clock buffer Design by Goh Ban Hok, Infineon Technologies, Singapore

DDS & converter form signal generator -  20-Feb-03 EDN-Design Ideas Polarity protector outperforms Schottky diodesMany applications require low-frequency signal generators that can deliver high-performance, high-resolution signals.  This design idea presents a circuit that generates frequencies of 0 to 1 MHz.  Sinusoidal, triangular, and square-wave outputs are available.  You can achieve frequency resolution of better than 0 Design by Colm Slattery, Analog Devices, Limerick, Ireland

DDS Device Produces Sawtooth Waveform -  10-Jul-03 EDN-Design Ideas Ramp or sawtooth waveforms are useful for a broad range of applications, including automatic-test equipment, benchtest equipment, and actuator control.  Discrete components typically set the waveform frequency.  Unfortunately, drift in these component values over time and temperature limits the accuracy of the output frequency Design by Niamh Collins, Analog Devices, Limerick, Ireland

DDS Device provides Amplitude Modulation -  09/02/99 EDN-Design Ideas Many applications require an analog output to assume different amplitudes, but many direct-digital-synthesis  (DDS) devices do not accommodate amplitude variations.  Test equipment uses DDS devices to generate signals of different frequencies.  However, the amplitude of these signals often must be variable, too.    Design by Mary McCarthy

DDS forms Inphase & Quadrature Generator -  12/04/97 EDN-Design Ideas Many instrumentation applications use two sine waves to carry out coherent modulation.  The circuit in Figure 1 allows you to measure vector magnitudes  (for example, voltage or impedance) by multiplying the measured signal with inphase and quadrature sinusoidal signals of the same frequency.  In a classic approach, these signals come from one VCO and a pi/2  (90º) delay.  However, when the measurements cover a wide frequency span, it is necessary to compensate phase differences between the measured and instrument circuits by using a programmable delay. Design by J Toda, R Bragos, and M Tresanchez, UPC, Barcelona, Spain

DDS Generates Precise PWM Waveforms -  10/02/03  EDN-Design Ideas Pulse-width modulation is a simple way to modulate, or change, a square wave.  In its basic form, the duty cycle of the square wave changes according to some input.  The duty cycle is the ratio of high and low times in the square wave Design by Colm Slattery Analog Devices, Limerick, Ireland

DDS IC plus frequency-to-voltage converter make low-cost DA - C -  02/05/04  EDN-Design Ideas Precision DACs are essential in many consumer, industrial, and military applications, but high-resolution DACs can be costly.  Frequency-to-voltage converters have good nonlinearity specifications—typically, 0.002% for the AD650—and  Design by Noel McNamara, Analog Devices, Limerick, Ireland

Dead-Accurate 6-Digit GPS-Locked Clock, Pt 1 -  Looking for a digital clock that's always dead accurate? This one derives its time signals from the GPS  (Global Positioning Satellite) system, so it never needs setting or adjusting.  It features big, bright 58mm-high digits for the hours and minutes, plus smaller digits to indicate the seconds.__ SiliconChip

Dead-Simple Circuit Masthead Amplifier -  Decided to take the plunge and get into digital TV? For most people, it's simplejust plug the new TV or set-top-box into your existing antenna.  But for many, the old TV antenna and cable just won't be up to it.  Here?s a new kit from Oatley Electronics which could solve your digital woes __ SiliconChip

Decimal to BCD Convertor -  This circuit will provide an output in Binary Coded Decimal from any of the input switches.  The input switches may be expanded to 16 switches, providing a Hexadecimal to BCD conversion  __ Designed by Ron J.

Definition of terms, Q&As -  Application Note__ MiniCircuits.com

Delay Unit for Surround Sound -  The Mitsubishi M65830 Delay IC has been discontinued  (for reasons beyond my comprehension) , and so far a suitable replacement device has not been found.  This means  (of course) that you will be unable to build this delay circuit.  I have left the project in place as reference, and the overall connection schematic is still valid if  (when?) a replacement for the M65830 is located.  The project will be updated at that time.  In the meantime, just ignore the delay circuit __ Designed by Rod Elliott  ESP

Delta Audio XL-02 Towers -  A high-power 2-way system that you build from a kit__ SiliconChip

Deluxe Lead-Acid Battery Zapper & Condition Checker  -  Improved design can check battery condition and has output sockets so that you can monitor the zapping pulses using a multimeter__ SiliconChip

Design Considerations for a Ku-Band DRO in Digital Communication System 5/99  -  App Note  Doc #928__ California Eastern Laboratories

Design Provides Single-Port-To-Dual-Port SDRAM Converter -  EDN-Design Ideas -- 03/03/11    Read and write operations won't interfere with each other. Design by Yu-Chieh Chen, Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, Taiwan

Designing Low Noise Amplifiers for PCS Applications 8/25/97  -  App Note  Doc #923__ California Eastern Laboratories

Developments in Battery Stack Voltage Measurement -  Linear Technology AN112 __ Designed by Jim WilliamsMar 2nd, 2007

Device Programmer-Atmel 89 Series -  Powerful programmer for the Atmel 89 series of microcontrollers that includes 89C51/52/55, 89S51/52/55 and many more.  With this article you can make your own programmer.  This is a complete programming solution when it is attached to a suitable power supply and connected to your personal computer.  Proload and Firmware Version 4.1 at 57600 speed.   __ Designed by Wichit Sirichote

Dialer -  This circuit is the up down circuit of the digital counter which used a rotary encoder.  Two sliding switches are incorporated into the rotary encoder.  The timing that each switch closes is shifted.  Because this circuit detects the timing that each switch closes, it judges the clockwise  (CW) or the counterclockwise  (CCW) of the switch, and adds or subtracts a counter __ Designed by Seiichi Inoue

Difference Amplifier uses digital potentiometers -  05/30/02 EDN-Design Ideas You sometimes need to measure a small signal in the presence of a large common-mode signal.  Traditional instrumentation amplifiers that use two or three op amps in their internal structure find common use in these applications.  The circuit in Figure 1 presents an alternative approach that is useful when low cost and low drift are important, but when you don't need high precision Design by Reza Moghimi, Analog Devices, San Jose, CA

Different Programs In the Chip using a PIC16c509 -  Scroll to find this circuit #3Up to 5 different programs can be burnt into a single '508A and the required program can be accessed by soldering a resistor between one of the outputs and the "input-only" lineGP3, as shown in fig: 4. 
During turn-on, a special program will put a HIGH on each output in turn and the output containing the resistor will determine the program.   __ Contact: Colin Mitchell

Digi Pack DMX 512 Lighting Controller -  This is a design for a digital lighting controler.   __ Designed by Paul Harris

Digisound ring Modulator -  Dual Ring Modulator based on MC1496.  The X and Y inputs are AC coupled and are capable of accepting 10V p-p signals.  Comprises two totally independent ring modulators on the same PCB which produces the sum and difference with two input signals.  Ideal for the production of a whole range of sounds including bell and gong sounds __ Designed by dave @ NO_SPAM_digisound80.co.uk 

Digital & Binary clock with thermometer & hygrometer -  Here we have a clock.  It's not another clock.  It has digital and binary output.  It also has a thermometer and a hygrometer.  It's not another thermo-hygrometer.  It display's absolutely humidity  (gr/m 3) also.  Schematic __ Designed by Konstantinos Bellosstyle

Digital Audio Delay for Perfect Lip Sync -  Do you have a large plasma or LCD TV set and a home-theatre system? If so, you may have problems with sound and picture synchronisation  (lip-sync) .  This Digital Audio Delay unit allows you to get the picture and audio perfectly matched.  to choose from.  To help you in this choice we gathered a number of these to test along with some expansion boards that might help you connect the Maximite to the rest of the world.__ SiliconChip

Digital Audio Signal Generator, Part 1 -  This Digital Audio Signal Generator has TOSLINK and coax  (S/PDIF) digital outputs, as well as two analog audio outputs.  If a digital output is used, the harmonic distortion from a high quality DAC is extremely low.  Alternatively, if you use the analog outputs the harmonic distortion of the sinewave signal is typically still very low at less than .06%.__ SiliconChip

Digital Audio Signal Generator, Pt.2 -  Last month, we described how the S/PDIF Digital Audio Signal Generator works.  This month, we describe how to assemble the PC boards, mount them in the case and check that they are working correctly.__ SiliconChip

Digital Audio Signal Generator, Pt.3 -  In the March and April 2010 issues, we described the design and construction of our new Digital Audio Signal Generator.  The final article this month has the driving instructions.__ SiliconChip

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Digital or Logic Circuits:  #'s - C       D - G       H - M       N - R       S - T       U - Z


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