POL IC Manufacturer Prefix - Page 1
Forum section: electronics / general

author: farlander762
author_rank: Contributor
timestamp: August 23, 2021, 11:18:02 pm
content: Has anyone ever run across an IC manufacturer prefix of POL? I have a Philips (BTM2180) mini stereo that I'm trying to fix and it has two POL4558 op-amps. Per the schematic, they should be NJM4558's. I've searched all over the Interwebs and found exactly nothing about POL or P0L. The sucker is 4mm square so it is difficult to photograph or I'd send a pic. EDIT: Daughter got a pic in their native environment. Likely failed one is top left mostly out of frame because it's on the edge of the board. They are the same.The one from the tuner appears to have a failed "A" channel. I get nothing downstream of that rig. The B channel works fine. I ordered 10 of the NJM4558E from Mouser to replace the bad one. The shipping cost more than 10 of them and I might kill one or three getting it soldered; again, itty bitty...

author: amyk
author_rank: Super Contributor
timestamp: August 24, 2021, 12:46:39 am
content: Couldtheybe rebranding stuff? That's the only thing I can think of that might seem plausible.

author: farlander762
author_rank: Contributor
timestamp: August 24, 2021, 01:21:16 am
content: I suspect they're clones. The actually measure 4mm square and the NJM is 4x5mm in that size class (SOP8).https://www.njr.com/electronic_device/products/NJM4558.html

author: Oldtestgear
author_rank: Regular Contributor
timestamp: August 24, 2021, 12:34:48 pm
content: Best to start by asking Mouser the question as they supplied them. IF they substituted these for a known brand then they ought to be able to provide full datasheets for the part. Just because a distributor is a multi national company does not mean they are immune from getting caught out if they have been buying on the spot market to support customers. The part may actually be perfectly acceptable, just from an little known vendor. These are the times that all sorts of companies may appear offering parts that are sourced from obscure wafer fabs.Back in the 1990s when stocks became tight we bought in wafers from Russian companies. The parts were actually very good copies of well known manufacturers that had been "second sourced" during the Cold war. For copies read identical mask sets. I actually toured a few Russian wafer fabs at the time to assess whether they did actually diffuse the parts in question.One customer complained that the parts we sold were not Russian in origin but from a well known European company. They really were that close to the original parts.Phil

author: farlander762
author_rank: Contributor
timestamp: August 24, 2021, 03:33:23 pm
content: The IC's that came from the factory in my stereo are the POL4558 units. The schematics for the stereo call out NJM4558. The replacements I ordered from Mouser are NJM4558E, well, they should be. I haven't received them yet.I'm just curious if anyone has ever heard of POL or P0L. I found exactly nothing about them after a pretty exhaustive search.

author: magic
author_rank: Super Contributor
timestamp: August 25, 2021, 06:49:14 am
content: Could be some obscure Asian manufacturer you have never heard about. It seems they are from 2012 so quite recent.4558 is a common generic opamp made by many vendors. NJM is not a bad choice.They look like standard SO8 so anything will fit.