• 40KHZ LED TEST SIGNAL GENERATOR
  This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses.  The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals.

• Ultra Low Power 32KHz Crystal Oscillator
  I have used this circuit many times when I needed a low frequency reference, which did not draw much power.  With the components show, the current from a 3v battery is less than 1.2 microamps.

• VERY LOW POWER GATED CRYSTAL OSCILLATOR
  The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and switching on a transistor power stage only as needed. The method keeps the standby power consumption to a very low 1uA when used with a 3v supply.

0.3V Crystal Oscillator Circuit with Buffered Output:   Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

0.5V Crystal Oscillator Circuit with Output Buffer:   Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

1 Second Time Base from Crystal Oscillator:   (Electronic circuit added 7/03)

2 Tone Audio Oscillator (use for SSB Tests):   (added 2/05)

32.768 KHz Oscillator using a Common Watch Crystal:   (Circuit / schematic design added 6/06)

5 Hints for Debugging Microcontroller-based Designs (AN 1458):   Agilent Application Note   (Circuit / schematic design added 6/06)

A Discrete, Low Phase Noise, 125 MHz Crystal Oscillator for the AD9850:   AN-419-Analog Device Application Notes  (Circuit / schematic design added 6/06) 

AN-1320: Enhancing CLC031 Jitter Performance with Easy-To-Use VCXOs:   National Semiconductor - Application Note   (added 2/06)

AN-400: A Study of the Crystal Oscillator for CMOS-COPS:   National Semiconductor - Application Note   (added 2/06)

AN-419: A Discrete, Low Phase Noise, 125 MHz Crystal Oscillator for the AD9850 :   AN-419-Analog Device Application Notes  (Circuit / schematic design added 6/06) 

AN-666: DTMF Generation with 3.58 MHz Crystal:   National Semiconductor - Application Note   (Circuit / schematic design added 6/06)

AN826: Crystal Oscillator Basics and Crystal Selection for rfPIC™ and PICmicro® Devices:   Microchip Application Note - Published 17-Jan-02   (added 2/06)

CMOS Oscillator:   (Electronic circuit added 7/03)

Components of a simple Bandpass filter:   (Electronic circuit design added 02/05)

Crystal 32.768KHz CMOS Oscillator:   (Electronic circuit added 7/03)

Crystal Considerations with Dallas Real-Time Clocks (RTCs):   Maxim Application Note #58 (Electronic circuit design added 02/05)

Crystal Controlled FM Transmitter:   (Circuit / schematic design added 6/06)

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)

Crystal Controlled Time Base Generator:   (Electronic Circuit / Schematic added 10/04)

Crystal Oscillator:   Chrontel Application Note-06 (Electronic circuit design added 02/05)

Crystal Oscillator #2:   (Electronic circuit added 7/03)

Crystal Oscillator #3:   Pericom Semiconductor Application Note # 083 (Electronic circuit design added 02/05)

Crystal Oscillator Basics and Crystal Selection for rfPIC™ and PICmicro® Devices:   Microchip Application Note - Published 17-Jan-02   (added 2/06)

Crystal Oscillator overcomes typical Drawbacks:   08/17/98 EDN-Design Ideas / (Electronic Circuit diagram added 03/03)  

CX Minature Crystals Circuits:   Euro QuartzCX-6V-SM (Electronic circuit design added 02/05)

CX-1SM Crystal 530kHz to2.1MHz:   Statek Application Notes (Electronic circuit design added 02/05)

Using the 16MHz Crystal Oscillators:   Freescale AN2500 (Electronic circuit design added 06/07)

FET Circuits Applications:   National Semiconductor Application Note 32, February 1970 (Electronic circuit design added 02/05)

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

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)

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

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)

One Second Time Base from Crystal Oscillator:   (Electronic circuit added 7/03)

Pierce Crystal Oscillator Design:   The Pierce oscillator ... is essentially a common emitter amplifier with a tuned circuit for a collector load and a quartz crystal as a feedback element. In order to determine whether the Barkhausen criteria is satisfied, loop gain must be determined at the frequency of oscillation. This is accomplished by drawing the AC equivalent circuit of the Pierce Oscillator... (Electronic circuit design added 02/05)

Pierce-gate Oscillator Crystal load calculator:   RF Design - Design Tips, July 2004 (Electronic circuit design added 02/05)

Specifying Quartz Crystals:   Maxim Application Notes / 726 / Dec-08  (Circuit / schematic design added 6/06)

Study of the Crystal Oscillator for CMOS CoPS:   National Semiconductor Application Note 04 Nov1995 (circuit / schematic added 2/03)

Tiny Crystal Oscillator #2:   High-stability gate oscillator uses two, 5-pin SOT packageddevices (Electronic circuit added 7/03)

Two Tone Audio Oscillator (use for SSB Tests):   (added 2/05)

Ultra Low Voltage Crystal Oscillator Circuit using Active Loads:   Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

Ultra Low Voltage Micropower Crystal Oscillator Circuit:   Circuit Ideas for Designers - Application Notes - Advanced Linear Devices, Inc.  (Circuit / schematic design added 6/06)

Use of the CMOS Unbuffered Inverter in Oscillator Circuit:   Texas Instrument Application ReportSZZA043 January 2004 (Electronic circuit design added 02/05)