Few Extra Components Stabilize Oscillator:  02/15/96 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

FIFO Makes Cheap Waveform Generator:  12/21/95 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)

FleaPower Oscillator Consumes only 1 µA:  05/21/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  A simple way to make an oscillator is to use a resistor, a capacitor, and a Schmitt trigger (Figure 1a). However, this circuit uses several tens of microamperes because of the voltage transitions at the Schmitt trigger's input. The CMOS device consumes almost no power when the input is either high or low. Whenever the input voltage is at an intermediate level, however, both the p-channel and n-channel transistors turn on partially, producing a significant increase in power consumption. The circuit in Figure 1b uses a Panasonic MN13812C comparator to form an oscillator. The comparator's threshold is rated at 2 to 2.2V, with approximately 0.1V of hysteresis. It has an inverted output; thus the output is low if VDD is higher than the threshold...

Flip Flop Flashers Buzzers Etc.:  (Electronic circuit added 7/03)

Function Generator #1:  (added 11/05)

Function Generator #2:  (Electronic Schematic / circuit added 4/02)

Function Generator:  Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

Gated Oscillator Emulates a Flip Flop:  03/16/95 EDN-Design Ideas / (added 03/03)

Gates Provide Low Cost Sine Wave Generator:  08/15/97 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  

Generate CID/CIDCW Analog Signals:  12/07/00 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) / A high-speed µP can generate CID (caller-ID) and CIDCW (caller-ID-on-call- waiting) analog signals (Figure 1). CID data transmits at 1200 baud FSK between the first and second 20-Hz ring of an incoming call. CIDCW uses a CAS (CPE Alert Signal) dual tone, which consists of 2130 and 2750 Hz to initiate the FSK data transfer. You can produce these analog signals using software-generated PWM (pulse-width-modulated) outputs from a high-speed µP, such as an Atmel AVR or Scenix SX. You create these PWM outputs using a constant-sampling frequency, and you select this frequency so that small, repetitive integer-number samples define the desired output. The 11.0592-MHz µP clock frequency and single-instruction cycle time are the same for IC1. The design produces the 1200-baud FSK marking frequency of 1200 Hz by using 22 cycles of a constant-sampling frequency of 11.0592 MHz/419. The design produces the 2200-Hz spacing frequency by using 12 cycles of the same sampling frequency. At each sample, the µP produces a PWM TTL output proportional to the analog....

Generate frequencies with arbitrary relationships:  03/16/00 EDN-Design Ideas / (added 2/06) The circuit in Figure 1 and the program in Listing 1 use an Atmel 89C2051 µC to generate a variety of frequencies that have no specific relationship to each other. The example given here generates the following eight frequencies: 500, 700, 1000, 1050, 1100, 1500, 1700, and 2000 Hz. The program delivers these frequencies on eight I/O pins (P17 to P10, respectively) of the µC. The program associates each of these I/O pins with an internal-RAM address (f1 through f8).

Generating and Downloading Data to the ESG-D RF Signal Generator for Digital Modulation:  Aligent Application Note  (added 2/06)

Generating Digital Modulation with the ESG-D Series Dual Arbitrary Waveform Generator, Option UND:  Aligent Application Note  (added 2/06)

Generating Low Duty-Cycle Pulses with a Function Generator (5988-7507EN):  Aligent Application Note 1407 (added 4/08)

Generator Features Programmable Duty Cycle:  11/23/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) The simple pulse generator in Fig 1 allows you to program its output's duty cycle. You apply your duty-cycle code to the B port of IC1, a 7485 magnitude comparator. The clock increments the 74193 4-bit counter, IC2. When the output of the counter is equal to or greater than your duty-cycle code, IC3 resets the output flip-flop, IC4, until the counter, IC2, overflows. Thus, your input code determines the output's duty cycle....  

HAM Radio BFO:  circuit diagram of beat frequency oscillator using BF494 and how to listen amateur radio communication on ordinary BC receiver. . (added 01/05)

Harmonic Oscillator:  (Electronic circuit added 7/03)

HCMOS Crystal Oscillator:  Fairchild Semiconductor Application Note 340, May 1983 (Electronic circuit design added 02/05)

How to Connect Two or More Signal Generators to Create a Multi-Channel Waveform Generator (5988-8151EN):  Aligent Application Note  (added 2/06)

I.F. Amplifier:  The I.F. transformer primary has 18 turns, the secondary winding has 4 turns. The capacitors across the IFT primaries are 82pF. The input/output transformer has 12 turns, tapped at 3 turns from ground. This transformer is wound on a ferrite core. The MOSFETs are 3SK45's. The diodes in the product detector are 1N34's. I use a six pole SSB filter from a scrap CB. The centre frequency is 7.8MHz. The -6db bandwidth is about 2.5KHz. (Electronic circuit design added 02/05)

Improved PL Tone Decoder:  (Electronic Schematic / circuit added 4/02)

JT-11ssp 6m as Input Transformer for Crystal Cs5367 A/D Converter:  transformer balanced passive input circuit for CS5367 A/D converter, PDF file (Circuit / schematic design added 6/06)

JT-6110k B at Input Stage for Crystal a to D Converters:  high performance transformer balanced input stage for Crystal A/D converters, PDF file (Circuit / schematic design added 6/06)

Kick start a crystal oscillator in SPICE:  02/05/2004  EDN-Design Ideas  In low-noise analog circuits, a high-gain amplifier serves at the input to increase the SNR. The input signal level determines the input-stage gain; low-level signals require the highest gain. It is also standard practice in low-noise analog-signal processing to make the circuit's bandwidth as narrow as possible to pass only the useful input-signal spectrum. (added 10/05)

LB-16: Easily Tuned Sine Wave Oscillators:  National Semiconductor - Application Note   (added 2/06)

LC (Colpitts) Oscillator operates on 0.5V to 5V Single Supply:  Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

LC Oscillator has 1% THD:  03/31/94 EDN-Design Ideas / (added 03/03) At the heart of many oscillators is a parallel-resonant LC tank circuit whose impedance is infinite at the resonant frequency of 1/2[pi]ÖLC Hz. Infinite impedance implies an absence of parallel damping resistance, so once an ideal tank circuit starts oscillating, it should continue indefinitely. An actual tank circuit, of course, has parasitic resistances that dissipate energy, causing the oscillations to die out. You can counteract this effect by adding a "negative" resistance, which cancels the net parallel parasitic resistance. Fig 1a's circuit uses a wideband transconductance amplifier to synthesize negative resistance easily....  

linkwitz Cosine Burst Generator:  part of speaker measurement set described in the construction article (Electronic circuit added 5/02)

Low Distortion Crystal Oscillator :  (Electronic circuit added 7/03)

Low Distortion Oscillator Starts Fast:  05/26/94 EDN-Design Ideas / (Electronic Circuit diagram added 03/03) Unlike a Wien-bridge oscillator, the phase-shift oscillator in Fig 1 starts up quickly. Also, the circuit does not require that you adjust several trimming resistors just to tune the oscillator to a given frequency. Experiments show that the circuit's total harmonic distortion (THD) measures approximately 0.5% or less. Connecting the output of a bandpass stage to its input via a phase inverter realizes a phase-shift oscillator. In practice, a phase-shift oscillator also needs a limiter stage. Unfortunately, the limiter can distort the output sine wave. Diodes D1 and D2 in the feedback loop of IC1A form a limiter that does not distort.... 

Low Frequency Crystal Controlled Oscillator :  The RF engineer sometimes has to look for an instrument that will check a low frequency quartz crystal unit reliably and rapidly. This is a difficult piece of equipment to find and the engineer often has to consult an electronic circuits handbook for the schematic of a circuit that will perform the task. Unfortunately, there aren't many such circuits in the technical literature currently available, and when found, they don't always work as expected. A circuit that has been found to work at full satisfaction in the frequency range from 10 kHz to 500 kHz is illustrated in Figure 1.  (added 11/05)

Low Frequency Sine Wave Generator:  The two circuits below illustrate generating low frequency sine waves by shifting the phase of the signal through an RC network so that oscillation occurs where the total phase shift is360 degrees. (Electronic circuit added 5/02)

Low-distortion Audio-range Oscillator:  Generates very low-distortion sine waves up to 1V RMS No thermistors required - No settling time (circuit design added 3/05)

Low-Pass Filter (RFI Filter):  Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)