Absolute Value Circuit Delivers High Bandwidth:  05/15/03 EDN Design Ideas  /  (added 1/05)  Most absolute-value circuits have limited bandwidth and high component count, and y require several matched resistors. The circuit in Figure 1 uses three fewer components than most absolute-value circuits require, and only two of  resistors must have 1% tolerance to obtain 1% accuracy. This circuit's output voltage is an accurate representation of  absolute value of  input signal,......

Absolute Value Comparator Touts Accuracy Size:  03/07/02 EDN Design Ideas  /  (added 1/05)  A typical window comparator uses two comparators and a single op amp to determine wher a voltage is inside or outside a boundary region. Figure 1 shows a typical implementation. IC1 is an inverting op amp with a gain of –1. VREF and –VREF create  window limits. When VIN becomes more positive than VREF,  output of IC2A goes low. ...

An IC Voltage Comparator for High Impedance Circuitry:  National Semiconductor Application Note   (app note added 2/06)

AN-41: Precision IC Comparator Runs from +5V Logic Supply:  National Semiconductor Application Note   (app note added 2/06)

AN-87: Comparing the High Speed Comparators:  National Semiconductor Application Note   (app note added 2/06)

Applications of the LM392 Comparator Opamp Ic:  National Semiconductor Application Note 04-Nov-1995 (app note added 4/02)

Circuit Techniques for Avoiding Oscillations in Comparator Applications:  National Semiconductor Application Note   (app note added 2/06)

Comparator Provides Stable Hysteresis:  03/18/99 EDN-Design Ideas / (added 7/03) Unless a voltage-comparator circuitis sampling an extremely clean signal, the comparator always requires some hysteresis. Traditional comparator circuits obtain the required hysteresis by using positive feedback derived from the ratio of two resistors. The voltage at the noninverting input is the superposition....

Comparator uses Signal Dependent Hysteresis:  03/26/98 EDN-Design Ideas / (added 03/03)  A project posed the challenge of replacing existing analog potentiometers (used to set brightness and contrast levels) in video monitors with digitally controlled potentiometers. The different brands and models of monitors presented widely varying voltages across the potentiometers....

Comparators Form 3 to 5 Volt or 5 to 3 Volt Translator/Tranceiver:  09/02/96 EDN-Design Ideas / (added 3/03) In many recent systems, you often need to interface 3V signals with higher voltages within the system. In some cases, it's necessary to interconnect 3 and 5V open-collector transceivers.Figure 1 shows one example, in which multiple multidrop communications devices interconnect. In systems where no control lines are available for interfacing, the translating transceiver must control

Comparing the High Speed Comparators:  National Semiconductor Application Note   (app note added 2/06)

Design an Efficient Reset Circuit:  05/01/03 EDN Design Ideas  /  (added 1/05)  When you work with microprocessors, you must ensure that when the power-supply voltage fluctuates to the minimum permissible level, VL, that the processor's ALU continues to operate normally. Also, when you switch on the power supply, the ALU must operate normally when the supply voltage equals or exceeds a certain high level, VH....

Design Low Duty Cycle Timer Circuits:  08/22/02 EDN Design Ideas  /  (added 1/05)  Designing astable circuits using the industry-standard 555 timer is a straightforward process when duty cycles are 50% or greater. However, you must overcome the many pitfalls of low-duty-cycle circuits to arrive at a desired result. Using only ideal components eases the design, but the components themselves are hard to obtain....

Electronic Fuse Emulates Fast  or Slow BLow Fuses:  11/09/00 EDN-Design Ideas / (added 7/03) The electronic-fuse circuit in Figure 1 combines the properties of a current transducer and a solid-state relay to disconnect low power at preset levels. Using this circuit lets you avoid the bother of stocking and replacing fusible links. The circu...

Expanded Scale Indicator Revisited:  08/08/02 EDN Design Ideas  /  (added 1/05)  The visualization aid that a previous Design Idea describes allows only the expansion of the upper end of the scale (Reference 1). But what can you do if, according to your project requirements, you need to expand the middle region of the scale? Figure 1a illustrates the challenge. A voltmeter comprises a 100-µA dc meter and a series resistor....

Fast Voltage Comparators with Low Input Current:  National Semiconductor Application Notes,28-Jun-1996 (app note added 4/02)

LB-12: Linear Brief 12 an IC Voltage Comparator for High Impedance Circuitry:  National Semiconductor Application Note   (app note added 2/06)

LB-32: Linear Brief 32 MicroVolt Comparator:  National Semiconductor Application Note   (app note added 2/06)

LB-39: Linear Brief 39 Circuit Techniques for Avoiding Oscillations in Comparator Applications:  National Semiconductor Application Note   (app note added 2/06)

LB-6: Fast Voltage Comparators with Low Input Current:  National Semiconductor Application Note   (app note added 2/06)

Light Sensor with Hysteresis:  (schematic / circuit added 10/02)

LM139/LM239/LM339 a Quad of Independently Functioning Comparators:  National Semiconductor Application Note 24-Feb-1999 (app note added 4/02)

Low Voltage Alarm:  NE555 Low Voltage Battery Disconnect Circuit (added 4/02)

MicroVolt Comparator #2:  National Semiconductor Application Notes,28-Jun-1996 (app note added 4/02)

MicroVolt Comparator:  National Semiconductor Application Note   (app note added 2/06)

Missing Codes Tester Checks 16 Bit ADC in 7 Sec:  06/10/99 EDN-Design Ideas / (added 7/03) As the resolution of ADCs increases from 12 to 16 bits and higher, the difficulty in testing the"nomissing-codes"specification grows proportionately. To fully guarantee no missing codes for a 16-bit ADC requires testing all 2 16-1 possible output...

Missing Pulse Detector (Basic):  (schematic / circuit added 10/02)

Precision IC Comparator Runs from Plus 5 Volt Logic Supply:  National Semiconductor Application Note 04-Nov-1995 (app note added 4/02)

Synchronized Window Comparator Eliminates Error:  05/11/95 EDN-Design Ideas / (added 3/03) Precision A/D converters need a window comparator. The window comparator in Fig 1a is synchronized to the clock signal. This synchronization eliminates errors that could arise when the input signal crosses the high or low threshold (Fig 1b) unsynchronized to clock. In operation, comparator IC1A sets flip-flop IC2A high when the input signal rises above the high threshold. Inverting comparator IC1B sets flip-flop IC2A low when the input signal descends past the low threshold. The second flip-flop, IC2B, synchronizes the first flip-flop's output to the rising edge of the clock signal. Obviously, the clock signal must be significantly higher in frequency than the input signal to avoid problems with metastability....

Two Buttons Provide Safe Start:  07/06/00 EDN-Design Ideas / (added 7/03) The circuit in Figure 1 provides a safety interlock that checks the actuation of two pushbuttons before enabling a relay. When you push both buttons, the circuit actuates the relay. At that point, you can release one of the switches without the relay'...

Voltage Comparator Forms Pulse Demodulator:  11/19/98 EDN-Design Ideas / (added 3/03)  

Voltage Comparator Information And:  (electronic design added 10/06)

Voltage Comparator Switch:  (electronic diagram added 6/03)