Update September 17 2021
The graph below is the mid-September update. Since July we've seen Digikey stock degrade further, by another 8% or so. However, note there's a slight uptick with inventory over the last 6-8 weeks or so.
Good news for now on this metric that may or may not matter in the end.
Update July 6 2021
The graph below shows Digikey's in-stock level for TI DCDC converters. Normally, TI carries about 2800 TI DCDC parts. These are the "normally stocking" checkbox on the webpage. Of the normally stocked parts, currently about 54% are in stock (46% out of stock).
Now, I'm sure TI or Digikey would say "Now, this graph doesn't tell the entire story" and they would be correct. But as long as Digikey is showing daily declines on stock levels, it's probably safe to say we haven't hit bottom. Buckle up.
The coming months are going to be difficult in terms of product availability as the semiconductor shortages continue. Normally, when it's time to build a more of a product, the process starts 3-4 weeks before the product is actually needed. Printed circuit boards are ordered from China, and take about 2 weeks to arrive. An order is placed with Digikey or Mouser, and parts arrive in a few days. And then both are taken to the assembly house, where the boards are are assembled in 5-10 days. The process is largely automatic: You decide how many you want, you push a button in automated ordering scripts that generate the bill of materials, and it all just works.
But for the last few months, it's not generally been possible to order everything from a single supplier. It has required purchasing parts from a few different suppliers as not everyone has everything in stock. But in the last month, it's gone to another level of disfunction.
The QA460 uses a part called the TPS62135 to generate a 10.5V rail from a 12V input. If you look on Octopart, there are zero parts anyplace in the system:
And if you look at lead times on Mouser, you can see parts aren't expected until this time next year.
And it's not just a matter of re-designing the board to use another DCDC converter. The situation is equally dire for just about any DCDC converter right now.
The upshot is that until things improve, we're going to have some large inventory gaps in our product portfolio that will manifest in the coming weeks, and they won't be fixable until the shortage starts to resolve. A magnetics supplier told me last week they they will be mostly caught up in late summer. The situation with passive discretes (resistors, capacitors, etc) is mostly fine. But the unique silicon situation is bad right now.