I am building a simple inverting operational amplifier circuit where I am using a chip with dual amplifier. I am only using one of the two amplifiers. What should I do to the unused amplifier's input pins? Should I leave them floating or is there a good way to sort of terminate them.
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I am using a dual op-amp package in a circuit, however I only need to use one. Is there anyway to disable the other op-amp so it doesn't inject electrical noise in my circuitboard? I think grounding the positive input and setting the op-amp into unity gain might be best, but I am not certain.
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I'm working on a relatively simple Arduino project and want to reach an elegant solution for a circuit. I'm not sure if there is an existing IC for what I want to do, but here is a diagram for what I'm attempting to accomplish.  When googling the solution I found the name to be an ABBA circuit (tagged by minecraft sadly), essentially I have 2 inputs which need to be switched when a 3rd logic trigger is activated. Can I do this with a single device? Or is there a more complex solution?  More stats: +3V line has ~170 mA of current Logic Switch is a +5V line with ~47 mA of current (Digital pin)  Thanks for taking a look and I appreciate any help given.
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What is the significance of a coupling capacitor in a common-emitter amplifier? What would happen if it is removed? What will be  the effect on AC amplifier gain on removing it?
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I bought an . When I saw the reference manual, I saw that it has several I/O modes.  For input: floating, pull-up, pull-down For output: analog, open-drain, push-pull  I have already worked with AVR MCUs which have tri-state and pull-up. So I can understand pull-up and pull-down, but, I can't understand the modes floating, analog, open-drain, push-pull. What do these modes mean and when do I use which?
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I am looking at  (dual low-voltage power amplifier). On the fourth page, there is a sample circuit; right at the V+ input there is a symbol that looks like a capacitor. However, it looks like it is shaded in. What is that?
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Consider a BJT serving as an amplifier. No suppose I need to  subtract the output obtained from two such  BJT amplifiers A1 and A2. Then I can simply  connect the output from A1 to one of the input  terminals of another transistor amplifier A3 and connect the other terminal to the output obtained from A2. In this way I can  obtain the output from A3 as the difference of two signals.    Now similarly suppose I need A non inverting amplifier. Then I can measure the output of a CE transistor amplifier in a reverse way so as to get the output in phase with the input. Now  consider an integrator circuit. When an ac source is connected in series with a resistor and capacitor then if the function to be integrated is taken as the current then obviously the voltage gives the integrand of the function (although multiplied by the capacitance).     In all the above situations I have sen opamps being used. When the circuit arrangement is as simple as mentioned above why do we use opamps(which have complicated internal circuit arrangements)? I don't intend to be a critic but rather I want to know the actual purpose for which opamps are used at the expense of simplicity?
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I'm a newbie in electronics and Trying to understand and build this circuit. would somebody tell me the rule of R1 &amp; C2 in this circuit and their magnitude effect on the controlling of process.why didnt feedback start just after the output of opamp?How could i find the transfer function between the voltage output of Hall effect sensor and the voltage output of MOSFET drain?  The schematic is the circuit of a magnetic levitating tool at:    Thanks so much
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I'm working on a 4 layer PCB with internal 2 layers being power and GND... 2 outside layers are signal. Is it better to have a pour on the outside layers or just leave them empty except for the signals?
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For the circuit of opamp 741. we have to supply the dual power for it. How can I make a dual power supply from single. For example, make a (+9V)-GND-(-9V) from single 9V battery ?
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Is there any IC that interfaces any 3.3V Input/Output to 5V Output/Input? I need it primarily for an Arduino Due but if there any bidirectional IC that works like that it would be great.  Some people advised me to use the SN74AHC125 and CD4050 ICs, but I don't understand how they work or how to interface with them.
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What is the difference between a differential op amp and a comparator? I know a comparator can only give me two values (the supply values).  The differential op amp amplifies the difference between the inputs...but should a comparator not do the same then? What is the specific difference?
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I'm working on a 9V VCO (synthesiser) that has three op amps, of which two needs virtual ground. So far I've been using voltage divider with a couple of caps and it works. I wonder if I need a separate power supply for each op amp? Is the TLE2426 any better? Do I need two of the TLE2426 for the two op amps?
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I've got an MCU with a 3.3V DAC onboard and I'd like to convert the 0-3.3V signal to a 4-20mA output. Any ideas on how to do this?
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I want to implement a simple circuit which can map -10V  +10V voltage range to 0V 5V voltage range. Thus I'm planning to use two op-Amps, one for the slope and the other for the offset. So basically I'm planning to use an inverting amplifier and a summing amplifier consecutively.  But Inverting amplifiers multiplies the input voltage with a minus sign. I need a positive slope. How can I overcome this?  Also Could you gibe me any ideas for a cheap op-Amp models for this purpose?
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Is the below a valid circuit implementation and are there any things to watch out for? It's a simplification of the larger circuit but the crux of it is that I need to sink current into two GPIO input pins. The pins are signified by the 1 and 0.  Also, would a diode on the pins be advisable?    Edit: Here's the non-simplified circuit. The question relates to the 3.3v part of it. In essence, the timer and decade counter sequentially pulse current, 'activating' the transistors one at a time. The keypad is a simple matrix keypad. What I'm wondering if I can do is to put a GPIO pin on the line between the keypad and ground. The intended effect is that, when a button on the keypad is pressed, 2 pins will change state - this signifies the row and column.  Note that some of the resistance and capacitance values are notional at the moment.
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The basic amplification schematics shown in the  datasheet shows a 250 uF capacitor in series with the output. I don't have any 250 uF, but I do have plenty of 470uF. If I understand correctly, is this capacitor used as a high pass filter, so should I be able to use a 470 uF instead of a 250 uF?   Also, is the resistor (10 ohm) and capacitor (0.05 uF) going to ground a low pass filter?
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I'm making a small project which will take +5v from USB, What should I do with the D+ and D-, keep it open or short them to ground or do I have to add some components?  I want to run ATMEGA168 and 16x2 LCD with back light.