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Ravaner
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Hello. I'm looking for a quad op amp similar to TL074 but rail to rail (mainly for input) in DIP14 (I found a lot in SMD) and supporting +12V / -12V as power supply.
Google found http://cds.linear.com/docs/en/datasheet/16789fs.pdfRavaner said:Hello. I'm looking for a quad op amp similar to TL074 but rail to rail (mainly for input) in DIP14 (I found a lot in SMD) and supporting +12V / -12V as power supply.
OOPS !Ravaner said:Thanks but I'm looking for DIP14 package not SMD
Adapters are available to do the conversion.Ravaner said:Thanks but I'm looking for DIP14 package not SMD
I don't think there is such a thing, at least not in bi-polar technology. Consider that the input stage will have an inherent VBE to turn on and that there must be a load for the first stage, in either the Emitter or Collector, to sense the change in current. It might be possible in MOSFET technology with a depletion mode input stage but I haven't thought it through completely. Your best bet is to put a voltage divider in the input to stay within the Common Mode range. You only need to lose 10% to 20% of input range, not a big hit for later gain stages.Ravaner said:rail to rail (mainly for input)
Ravaner said:looking for a quad op amp similar to TL074 but rail to rail (mainly for input)
Tom.G said:FURTHER DIGGING:
You may be able to use a couple of MOSFETs as a pre-amp input stage to get close to rail-to-rail input but it seems like a lot of added complexity for little gain.
A Google search shows a few hits for rail-to-rail input but they are low supply voltage (7V), single or dual, and small packages.
https://www.google.com/search?q="op+amp"+depletion+mode+input
CWatters said:I see someone already suggested adaptors.
Tom.G said:I don't think there is such a thing, at least not in bi-polar technology. Consider that the input stage will have an inherent VBE to turn on and that there must be a load for the first stage, in either the Emitter or Collector, to sense the change in current. It might be possible in MOSFET technology with a depletion mode input stage but I haven't thought it through completely. Your best bet is to put a voltage divider in the input to stay within the Common Mode range. You only need to lose 10% to 20% of input range, not a big hit for later gain stages.
Interesting approach! I'm interesting in following up on it. Can you point me to a datasheet so I can follow up?analogdesign said:The key idea is to put a PNP diff pair in parallel with a NPN diff pair.
A quad rail to rail op amp is an operational amplifier that has four input and four output pins, allowing for four separate signals to be amplified simultaneously. It is also capable of operating with both positive and negative power supplies, allowing for a wider range of voltage levels to be amplified.
A regular op amp typically has only one input and one output pin. This means it can only amplify one signal at a time and is limited to operating with a single power supply. A quad rail to rail op amp, on the other hand, has four input and output pins, making it more versatile and capable of amplifying multiple signals simultaneously.
The main benefit of using a quad rail to rail op amp is its versatility. It can handle a wider range of input and output signals, making it useful for a variety of applications. It also allows for more precise control over signal amplification and can operate with both positive and negative power supplies, making it suitable for both single and dual supply systems.
Quad rail to rail op amps are commonly used in applications where multiple signals need to be amplified, such as audio and video equipment, instrumentation and control systems, and medical devices. They are also useful in low-power and battery-operated devices, as they can operate with lower supply voltages.
While quad rail to rail op amps have many benefits, there are also some limitations to consider. They typically have lower bandwidth and higher noise levels compared to regular op amps. They also tend to have higher power consumption, which can be a concern in battery-operated devices. Additionally, not all quad rail to rail op amps are suitable for high-voltage applications, so it's important to carefully select the right one for your specific needs.