Party Line Intercom :  (diagram added 6/03)

Phonograph Disc Playback PreAmplifier :  (diagram added 6/03)

Phonograph Disc Record Amplifier :  (diagram added 6/03)

Piecewise Linear Amplifier Eschews Diodes:  10/12/95 EDN-Design Ideas / (added 4/02)  

Portable Mixer for Nagra Recorder :  (diagram added 6/03)

Power Amplifier has Transient Rail-to-Rail Swing:  09/29/94 EDN-Design Ideas / (added 6/06) Has transient rail-to-rail swing special common-drain MOSFET-based power op amp circuit

Predicting Op Amp Slew Rate Limited Response:  National Semiconductor Application Note   (app note added 2/06)

Program designs single supply op amp circuits:  10/26/95 EDN-Design Ideas / (added 6/06) 

Pushing Low Quiescent Power Op Amps to Greater Than 55dbm 2-Tone Intercept:  National Semiconductor Application Note   (app note added 2/06)

PWM Circuit uses One Opamp:  07)/06/00 EDN-Design Ideas / (added 5/03) circuit delivers a rectangular signal with duty cycle varying between0 and100% in response to an input signal varying from0 to5V dc

Rail-To-Rail Amplifiers Operate on 2.7V with 20µV Offset:  DN230  Design Notes (Linear Technology) (app note added 1/06)

Rail-To-Rail I/O and 2.4V Operation Allow Ultrafast Comparators to Be Used on Low Voltage Supplies:  DN248  Design Notes (Linear Technology) (app note added 1/06)

Rail-to-Rail Op Amp Provides Biasing in RF Amp:  01/20/00 EDN-Design Ideas / (added 11/05)

Rail-to-Rail Voltage Comparator:  Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc.  (app note added 6/06)

Rail-to-Rail Voltage Comparator-23007.0:  Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc.  (app note added 6/06)

Rail-to-Rail Voltage Follower/Buffer:  Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc.  (app note added 6/06)

Rail-to-Rail Window Comparator-23008.0:  Circuit Ideas for Designers Application Notes Advanced Linear Devices, Inc.  (app note added 6/06)

Reducing DC Errors in Op Amps (Addendum to AN241 and 242):  National Semiconductor Application Note   (app note added 2/06)

RF Oscillator uses Current Feedback Op Amp:  10/03/02 EDN Design Ideas  /  (added 12/04)  A current-feedback amplifier is a well-known component with many uses. Its basic block diagram shows that its input stage is a voltage follower—in practice, a symmetrical emitter follower (Figure 1). The configuration samples the output current, converts it to voltage across a large impedance, and amplifies it to the output using a high-power, low-output-impedance amplifier....

Selecting Op Amps for Precision 16-Bit DACs:  DN214  Design Notes (Linear Technology) (app note added 1/06)

Settling Time of Operational Amplifiers:  AN-359 Analog Devices Application Notes  (app note added 6/06)

Simple Differential Front-End for the LTC2400 Simple Rail-To-Rail Circuit Converts Differential Signals to Single-Ended Signals and Operates on Single or Dual Supplies Where Resolution is More Important Than Accuracy:  Design Solutions 2  Design Notes (Linear Technology)  (app note added 1/06)

Simple Op Amp Radio (ourworld):  (electronic circuit added 7/03)

Simple Op-Amp Radio:  This is basically a crystal radio with an audio amplifier which is fairly sensitive and receives several strong stations in the Los Angeles area with a minimal 15 foot antenna. Longer antennas will provide a stronger signal but the selectivity will be worse and strong stations may be heard in the background of weaker ones. Using a long wire antenna, the selectivity can be improved by connecting it to one of the taps on the coil instead of the junction of the capacitor and coil.... (added 2/07)

Simple Timer Exploits Opamp Bias Current:  07)/21/94 EDN-Design Ideas / (added 5/03) The simple, low-cost analog timer in Fig 1 exploits the parasitic input-bias current of op-amp IC1. The timer achieves long time delays even though it uses only low-value, inexpensive ceramic chip capacitors. After all, because the input-bias current is the minimum current flow into an op amp, this method produces the longest time delays possible from a given capacitor and op amp....  

Simplified Test Set for Op Amp Characterization:  National Semiconductor Application Note   (app note added 2/06)

Simulation SPICE Models for Comlinear's Op Amps:  National Semiconductor Application Note   (app note added 2/06)

Single NiCd Cell Drives Opamp:  12/05/96 EDN-Design Ideas / (added 5/03)

Single Op-Amp Bandpass Filter:  A bandpass filter passes a range of frequencies while rejecting frequencies outside the upper and lower limits of the passband. The range of frequencies to be passed is called the passband and.... (added 2/07)

Single Polarity Powe Supply Circuit for 400 Series Amplifiers :  (diagram added 6/03)

Slow Opamp Makes Fast Multivibrator:  01/01/98 EDN-Design Ideas / (added 5/03)  

SOT-23 Micropower Rail-to-Rail Op Amps Operate with Inputs Above the Positive Supply:  DN221  Design Notes (Linear Technology) (app note added 1/06)

SOT23-6 Op Amp Evaluation Board:  National Semiconductor Application Note   (app note added 2/06)

Source Resistance Induced Distortion in Op Amps:  DN84  Design Notes (Linear Technology) (app note added 1/06)

Specifying Selected Op Amps and Comparators:  National Semiconductor Application Note   (app note added 2/06)

SPICE-Compatible Op Amp Macro-Models:  AN-138 Analog Devices Application Notes  (app note added 6/06)

Stability Analysis of Current Feedback Amplifiers:  National Semiconductor Application Note   (app note added 2/06)

Swopamp Makes Square Wave Generator:  02/15/96 EDN-Design Ideas / (added 5/03)

Synchronous Modulator:  This unique circuit uses a very small amount of battery current and has excellent carrier suppression. Its only shortcoming is that you must limit the input signal to 0.7 Vp-p in order to prevent distortion. To use higher input voltages, replace Q3 with a JFET. A MOSFET doesn’t do as well as an NPN transistor.  Designed by Andrew R. Morris  (added 09/05)

Synchronous Modulator-1:  This is an OpAmp version of the synchronous modulator I submitted earlier. It has more consistent performance over varying power supply voltage than the discrete version, but it still has the 0.7 Vp-p limitation on the maximum input voltage. You should use a JFET or a CMOS switch in place of Q1 if you need to accommodate a higher input voltage. Also, a low pass filter needs to be added after the output of this circuit, where the discrete version had one built in.  Designed by Andrew R. Morris  (added 09/05)