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.
The discussion revolves around finding a quad rail-to-rail operational amplifier (op amp) similar to the TL074 in a DIP14 package, suitable for a power supply of +12V / -12V. Participants explore various options, specifications, and potential alternatives while addressing the challenges of sourcing such components in the desired package type.
Participants do not reach a consensus on the availability of a suitable quad rail-to-rail op amp in DIP14 format. Multiple competing views exist regarding the feasibility of achieving rail-to-rail input with different technologies and approaches.
Some limitations are noted regarding the specifications of suggested op amps, including power supply constraints and performance characteristics that may not meet the needs for audio applications. The discussion also highlights the challenges of sourcing components in the desired package type.
This discussion may be of interest to electronics engineers, hobbyists, and students looking for operational amplifier solutions, particularly those focused on audio applications or requiring specific packaging formats.
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.