Go Down

Topic: Looking for an IC... Does it exist? (Read 812 times) previous topic - next topic



I'm looking for an IC that converts an analog voltage signal to a signal that is either high (5 Volts) or low (0 Volts). I was thinking about using a Schmitt trigger but I would like to be able to adjust the voltage level of the "switchpoint" between high and low, for example by using a potentiometer. Does an IC like this exist? Could you please post the name of the IC or the datasheet? And if it doesn't exist, how can I build a circuit like this myself? Please let me know.


Jack Christensen

Sounds like that could be a voltage comparator. I believe many AVRs include analog comparators, so if an MCU is part of the design, a separate comparator may not be needed. From the ATmega328 datasheet:
22.1 Overview
The Analog Comparator compares the input values on the positive pin AIN0 and negative pin
AIN1. When the voltage on the positive pin AIN0 is higher than the voltage on the negative pin
AIN1, the Analog Comparator output, ACO, is set. The comparator's output can be set to trigger
the Timer/Counter1 Input Capture function. In addition, the comparator can trigger a separate
interrupt, exclusive to the Analog Comparator. The user can select Interrupt triggering on comparator
output rise, fall or toggle.


Analog Comparator, or a cheap operational amplifier (without feedback loop) will do that.

It might be worth to have a read on the ATmega328 manual. There is an analog comparator onboard the Arduino chip.
This... is a hobby.


You could use an op amp or comparator suchs as the LM358 that the arduino's use for power switching comparison.
Your signal goes into the + pin, the -pin gets connected to a trim pot that you set to the swithover voltage;
If the + pin has lower voltage than the - pin, the output is low, and if higher the output is high.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Go Up