Replacement for OPA627?

Member
Joined 2011
Paid Member
The OPA627 Product Details page on Texas Instruments' website suggests a compatible replacement, see below. T.I. also provide a side-by-side comparison table (here) . If you prefer to use an actual OPA627 in SMD package, but are unwilling or unable to solder an SOIC-to-DIP adapter yourself, I would be happy to solder it for you, free of charge. You only pay the round trip shipping fees. Send me the ICs, the SOIC-to-DIP adapter PCBs, and the thru-hole "legs" which fit your adapter boards. I'll solder them together and test them to verify they work, then send back to you. Send PM when you've got everything together and ready to ship.

_
 

Attachments

  • screen_capture.png
    screen_capture.png
    21.5 KB · Views: 137
  • Like
Reactions: 1 users
There is the added benefit that the totally awesomely specified OPA828 is a whole bunch cheaper than the much earlier generation OPA627. As Mark says it is only available in surface mount, but that is the way the whole electronics industry is heading.
 
  • Like
Reactions: 1 user
Rochester Electronics claims to have 41K of the PDIP in stock. Min order of 7 pcs. I've used them before and they are legit. I would pretty much guarantee that anything from eBay, ali, etc. would be a fake.
The SOIC8 from Mouser, etc. would be your best bet. I would recommend the Aries SOIC8-PDIP8 adapters (LCTQ-SOIC8) unless you can work out a deal with stellavox.
 
Thank you to all for the suggestions and major offers of help.

I've seen all the options of 'bulk' buys through partner stores etc. Rather more $$ than I believe the owner will pay. Possibly more than what this thing is worth.
ebay, ohhhh no, I prefer proper channels for all my parts :)
This device has mosfets driving the output so I'm thinking the load on the opamps will be very low. irf9z34 / irfz24. 55v 17amp devices.
Doing the smd adaptor boards with smd versions isn't an issue for me at all.
I was just hoping for a plug in option.
I'm not too concerned about how it will sound compared to the correct opamps. A slightly lower quality device would be ok for me.
Gent got it second hand and it never worked, so we have no idea how it 'should' sound to start with.
There's no markings on the case at all. but the pcb has amb m3 screened on it. I haven't looked it up so no idea if it's good or not :)
Guess I'll price up a smd adaptor with opa828 and see what the owner wants to do..

Edit.
Ahhhhhhhhh always look for the obvious = me lazy.
Just did something I should've started with.
Voltage to the board is 24vdc.
Voltage supply at the opamps is 3vdc. Yes across pins 4 and 7.
Stated range is 9-36vdc.
Somehow I think I need to look into the power supply to the opamps :p
 
Last edited:
The OPA627 Product Details page on Texas Instruments' website suggests a compatible replacement, see below. T.I. also provide a side-by-side comparison table (here) . If you prefer to use an actual OPA627 in SMD package, but are unwilling or unable to solder an SOIC-to-DIP adapter yourself, I would be happy to solder it for you, free of charge. You only pay the round trip shipping fees. Send me the ICs, the SOIC-to-DIP adapter PCBs, and the thru-hole "legs" which fit your adapter boards. I'll solder them together and test them to verify they work, then send back to you. Send PM when you've got everything together and ready to ship.

_
I may be stupid here , but TI states that the OPA827 has rail to rail output ?
https://www.ti.com/compare-products...ernate-gpn&partList=OPA627,OPA828&sticky=true
Figure 6-18 & 6-19 , says no. But I maybe wrong .
https://www.ti.com/lit/ds/symlink/o...l=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA828
 
Hi RickTH
There was an error in the model number in your post, and at first I thought you were claiming that "OPA627 is not rail-to-rail, but TI says it is."
I was a little confused, but I guess you meant to say that OPA828 isn't actually rail-to-rail.
I have posted the confirmation results here.
Thanks for letting me know.
 
Yes sorry , I meant the OPA828 of course . With 627 and 828 and there is an 827 too , an easy error. Now I kinda understand Mark J's post.
But in the TI comparison is an error too . OPA 828 is not rail to rail . That is why I kept it on 2 x 15 V instead of 2 x 12V to keep the chip cooler.
Thanks for the correction and confirmation.
 
  • Like
Reactions: 1 user
An opamp cannot possibly do rail to rail. There are at least voltage drops in the drivers, Vce(sat) in the output pair, and a further drop in the emitter resistors of the output pair. So you ultimately be limited to at least 2V between voltage rails and peak output voltage. So for example if the rails are +/-15V the maximum output swing will be +/-13V or very close.