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hi, 1-why ADC op-amp use -5v 0v +5v supply power why not use single supply?? 2-the -5v 0v +5v connected to low voltage 3v ADC that's mean more op-amp gain can damage the high cost ADC ?
Hi, You didn´t specify input_voltage range. I´d use a comparator instead of an opamp (Because it is desigend to be a comparator). And add some hysteresis. What comparator to use depends on your signal voltages, supply voltages, hystereis circuit and output behaviour. Klaus
Saw a few times, counterparalleled LEDs driven by the single output of a single-supply operational amplifier circuit. /-------------------|<|---------------\ opamp out >------ -------- gnd \-------------------|>|--------------- Second way, the (...)
I constructed non inverting DC amplifier using 1/2 LM 358 with a gain of 10 employing the standard circuit. It does work at single supply of 5 V. Every thing is fine if the output levels are less than 3 V approximately. The output never exceeds certain value that ranges from 2.6 to 3 V irrespective of gain and input. Some sort of saturation lik
If you just want that the circuit works somehow, then you can use almost any other opamp. But if you want the same performance, then it might be difficult. Any opamp with input voltage range including negative rail and suitable output voltage range, TL072 e.g. won't work. Look for "single supply" or "rail-to-rail" OPs in (...)
135454 135455 1)Most opamp use nmos differential amp, but this one uses pmos. why? nmos is faster. 2)the third stage, buffer stage gain, and on the circuit, it shows 2 pmos(m8, m9). why? isn't it inverter is used as buffer? how's 2 pmos is a buffer?
The results with the single supply voltage depend on the output impedance of the power supply. The circuit you show feeds half of any hum and noise on the positive supply to the reference input of the opamp. Do it liked this:
Thank you for you reply! And sorry for my lack of precision... The input voltage comes from a 3V linear regulator, which is itself supplied by a battery. I don't need a high precision on the output voltage, but I need it to be as flat and stable as possible: noise and drift are an issue. The output will be used as a ground reference for an ampl
Hello, I have collected a direct conversion receiver on 3 breadboards: the first one contains rf stage, the second one contains opamp audio preamplifier/bandpass filter and the third LM386 audio amp in minimal configuration with gain 20. The rf part is based on NE612 famous mixer. The receiver works quite weel (I can hear 10 nanowatt beeping
Hello guys, a stupid and quick question I am checking tha datasheet of one opamp Rail to Rail which maximum VCC suplpy acording to this datasheet is +-22V. Is it possible to supply it between 0V and 24V or can i break it? I think that it is possible but i need to confirm this issue. Thanks in advance!
Most half-decent opamps have maximium supply voltages of 36V and 44V so 24V is no problem. They work well up to at least 100kHz. A 741 opamp was designed 47 years ago and has trouble above 9kHz.
An important specification for an opamp is the range of its useable input voltage. Some opamps have a limited input voltage range that might be 3V or more away from a positive or negative supply pin like a 741 opamp then if it has a single positive supply its inputs do not work if their (...)
If you apply a positive voltage to the (-) input of an opamp then its output will be saturated as low as it can go. The negative input of a linear opamp is used for negative feedback, not a DC voltage. The (+) input of an opamp is its reference voltage input and if it is at half the supply voltage and the (...)
The circuit does in fact a negative instead of the intended positive level shifting. Quite obviously, a single supply non-inverting amplifier can't process the negative input voltages corresponding to negative currents. A simple way to achieve a positive level shift is to use two resistors and a reference voltage. No OP needed
Some opamps like the LM324, LM358, TLE2141 and rail-to-rail opamps have inputs and an output that work down to 0V when the supply is only positive.
Hi, Thanks for reading my message. I am making a high impedance measuring device that measures input voltage in the range of 0v up to 34V. Now I generate 36V for the input opamp and this first stage is a 1x buffer. Is there an opamp solution that only needs a single voltage supply (3v3) and that can handle 0v-34v and has (...)
Why do you need a dual-polarity power supply? ANY AC opamp circuit will work with a single supply voltage if its (+) input is biased at about half the supply voltage and the signal input, output and feedback to ground parts are capacitor-coupled. Here is an example:
The 'scope photo you posted shows no DC voltages. Is the output of the opamp at about 0V? Then since it has apositive-only supply, the negative parts of the input are missing from the output. 1) The input DC voltage is 0.43V lower than the voltage divider on the inverting input so the opamp amplifies the difference 21 times and forces its (...)
ANY opamp works from a single polarity supply if its input is biased at about half the supply voltage.
The PNP transistor inputs of an LM358 dual opamp work perfectly when they are at the voltage of its negative supply pin so it can be a single positive supply inverter when it has a negative voltage to its input resistor. Its output goes as high as +5V only when its supply is about +6.5V.
I notice that the resistor values are VERY low. The TL064 and LM324 are low power opamps but the low resistor values use fairly high power. I agree that an LM324 will work fine in this circuit since its minimum supply is 3V and its inputs work when they have a voltage as low as the negative supply which is 0V in this circuit. An LM324 has (...)
This design is extremely popular since the input works below ground on a single supply and is very cheap to produce.108199 Thanks! Yes, the one you showed is a BJT opamp with pnp pair input so that the input can go below ground.
On the other website the OP admits that the circuits are identical but the malfunctioning opamp has a higher input voltage of 0.9V and the good opamp has an input of 0.6V. So obviously the opamps are fine and the signal source that has a voltage too high is defective.
i want to switch on and off a dc fan using mosfet depending upon lm35 output. so i build the below circuit, but it does not work. can some one please tell what i am doing wrong? op amp pin 2 is at 0.25v and pin 3 at 0.32v R11 is not connected. VCC is 12v 106839
For 5v supply (5v and gnd) you should use single supply opamp like LM358, LM324 etc. You should not use 741. For LM311 issue, check the operation of LM311 in a bread board using a potentiometer and two resistors as voltage divider. You first need to make sure that LM311 is working properly. Upload schematic, otherwise it is (...)
Hi, I have designed an opamp of gain 120dB and ugb in the range of 2-3 MHz with power consumption nearly 0.5 mw and settling time is in the range of 200 ns with a single power supply of 1.2V. I have a query that which area needed such an opamp specification........ I have read papers on high gain low power (...)
The (+) input of the opamp on your first schematic does not have an important "ref" voltage. Its DC voltage is whatever is the input source voltage which might be 0V. That's a perfectly valid topology-the only issue is the common (ref).
The Max Vs is typically listed under the parameter search table: That may not necessarily be the max single rail supply allowed, because a value of +- 25v would appear as 50v in that table and I'm not sure that all the opamps take the middle point between Vcc- and Vcc+ as reference for the max supply, or some of them have a (...)
The first opamp has no power supply shown (single or dual supply?) The 2nd opamp has no dc feedback and single supply. Cannot work. Where does the circuit comes from?
A TL081 is good or an NE5534 is even Lower Noise. BOTH of these require +/- supplies. No they don't. ANY opamp can use a single supply if its input is biased at half the supply voltage. Coupling capacitors might be needed.
Usually a Sallen-Key filter is biased at half the supply voltage so its output can swing up and down. Your circuit uses the amplifying opamp as a rectifier because it has a single supply, is biased at ground therefore its output swings only positive. Your Sallen-key filter design with gain has bizarre resistor and capacitor (...)
A 741 opamp is 45 years old and was not designed for audio because it has too much hiss and has trouble above only 9kHz. A TL071 is a good single audio opamp that has low noise and works well up to 100kHz.
i can't make any circuit from filterpro to work in multisim with single supply +5V opamp Sounds like a trivial point, add suitable DC bias, which isn't provided in the FilterPro circuits.
you need an opamp that works from a single low voltage supply PLUS a 5V voltage reference. Use an LM10. It has a low voltage opamp and an adjustable voltage reference in an 8-pins package.
Hi, Has anybody used ideal opamp from cadence ahdllib. I am trying to simulate it with Vsupply_p=1.2V, Vsupply_n=0V and Vref=600mV in unity gain configuration. However, for a sine wave input, output is just a constant dc voltage. I tried to change different parameter values but it did not work.
Hello, I need our (single supply) MCP601 opamp follower (U17 in below schematic) to be able to drive its output down to as low as about 10mV above ground?.and still be operating in the linear region. However, page 2 (near bottom) of the MCP601 datasheet states that MCP601 can only drive to within 100mV of ground..However, this (...)
It is easy to use a single polarity supply. Simply bias the inputs of the opamps at half the supply voltage with 2 resistors as a voltage divider and use input and output capacitors.
Hi all, I am now designing circuit using AMS C18 process. Its core power supply is 1.8V. I start from very basic block, say PMOS-input 2 stage opamp. The common mode input range is from near zero volt to about 1V. DC bias at 0.5V gives the best result of gain, and it also gives wide range of input signal amplitude. But Here is the quest
Trevorth - Why don`t you use the classical double supply operation? single supply requires some special bias provisions. Check your dc quiescent point at the opamp output. What voltage do you expect? This opamp will work perfectly fine with a single supply. Common mode (...)
hi all, pls tell me some low cost opamps woking on battery (single supply). is it possible for lm 741 to work in single supply ? thanks.
You HAVE to use the negative input of the opamp for summing, also there must be negative feed back to this point so it is a virtual earth. Frank
I need to design a low power single supply cmos opamp. Please help me with a schematic as I have to submit it by sunday night. You make-design IC ? Or you need to use CMOS opamp in some circuit ?
What do you want to trim?? single opamps have offset adjust pins where you connect a pot. Most opamp circuits have their input biased at half the supply voltage (or ground if there is a dual-polarity supply) by two resistors, not a pot. Sometimes a pot is used to adjust the amount of gain. Sometimes a pot (...)
Hi I'm trying to measure the open loop gain of an opamp in the lab. I'm trying to implement the first circuit in from the pdf below Just want to input on how this circuit works. Is it currently configured to work on a single supply opamp, or do I need to change
741 can't work correctly because the output can't go near the power supply voltages and the input range can be a problem too. A different opamp that can go down to 0 level should solve that. Can you try lm358? Note that it can go down to 0 but no up to Vcc so the topmost diff amp may still not work properly. A rail to rail model should solve th
Hello, I am using the LM7705 (charge pump) to provide a negative bias supply voltage for a previously single supply opamp ( i wish to get the Vout of the OPA335 opamp to go to zero).....however, i am trying to work out what the capacitor values are that i need to use............. What do "V1" and (...)
Hello, I am using an OPA335 opamp as a differential amp with a gain of 100.... ...sometimes the input signal will only be 500uV, which would mean an output voltage of 50mV , which is lower than the 100mV minimum achievable output voltage when the OPA335 opamp has a single supply. .....If i use the LM7705 to (...)
Greetings, I am having some trouble finding out how to implement a negative DC shift with an opamp. I am trying to read a sensor that outputs a voltage that ranges from 325 mV to 265 mV. I would like to shift this signal by approximately -265 mV, meaning that I would get a final waveform that ranges from 0 - 60 mV. From there, I can then amplify
I suspect the first opamp is running off a single supply; thus as the input goes negative, the output is forced to ground.
1) No, you won't hurt the opamp 2) You have to look at the particular opamp do determine how it will perform when driven to the power supply rails-there's no single answer to that question. 3) You might rather use a comparator than an opamp for this function. (If you can find one that will work at these voltages)