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From looking at the specs of the LF347 quad op amp, it seems the specifications are basically identical to the TL074. I do know though the LF347 has a higher current output then the TL074; 31mA max output of the LF347 vs 10mA max output of the TL074.

Another interested thing is that Texas Instruments, uses the same functional block diagram for these op amps , on their pages for the LF347 and TL074/84 series etc.

Texas instruments op amp block diagram

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  • \$\begingroup\$ The specs for the LM247 appear identical to the TL074. But I have seen and used thousands of TL074 and stereo TL072 audio opamps and have never seen an LM347. Today, the TL074 is still made, stocked and sold but the LM347 is obsolete. \$\endgroup\$
    – Audioguru
    Commented Nov 12, 2021 at 1:46
  • \$\begingroup\$ Not so sure the LF347 (not LM) is any more obsolete than the TL074 series. But when the TL074 manufacturer bought the LF347 manufacturer, it's likely they rationalised production (but TI still make many Nat Semi parts where there is no direct equivalent). \$\endgroup\$
    – user16324
    Commented Nov 12, 2021 at 16:10
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    \$\begingroup\$ @user_1818839 also the LF347 use to be a 4mhz gbw op amp, but ever since Ti had manufactured the IC, it became a 3mhz gbw op amp , the same as their 074 series op amps. \$\endgroup\$
    – Michael Weaser
    Commented Nov 12, 2021 at 18:25

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There’s LF347 that seems to be just TL074 by another name. That’s not what you’d have bought in the 80s from NatSemi. There’s also LF347-N, which is the NatSemi design, with an output stage with active current limiting that doesn’t merely use series protection resistors like TL074 does.

TI has made a bit of a mess with those LF347 part numbers. In many applications, TL074 or “LF347” is an OK replacement for LF347-N and NS LF347. In a few, LF347-N is required for stability or transient response where NS LF347 was used. It’s a direct 1:1 replacement.

I’ve recently been reacquainting myself with those parts from the heyday of my youth, it’s a blast from the past. TL07x is still a workhorse part.

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    \$\begingroup\$ That is kinda what I thought , I found out the LF347BN/NOPB or LF347N/NOPB version seems to have the same specs as the original NatSemi version, as those versions seems to have the same 4 MHz bandwidth, while all the non /NOPB versions seems to have similar specs to the TL074 including the 3 MHz bandwidth. All of this information is from mouser.com , if you search the LF347 on their website. \$\endgroup\$
    – Michael Weaser
    Commented Feb 12, 2022 at 15:47

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