Automotive Ethernet 100/1000BASE-T1 PHYs Are Now a 26-Week Story: Why Industrial Buyers Are Sharing the Same Foundry Slot

By Procurement Priya · icboms supply-chain desk · data through August 22, 2026

A Tier-1 EV integrator in Shenzhen placed an order last Tuesday for 18,000 pieces of TI's DP83TC812SRHARQ1 — a 100BASE-T1 automotive Ethernet PHY in a 36-pin wettable-flank VQFN — and got a 24-week confirmation from the franchised channel. Their purchasing manager did the math on the spot: that order commits him through the end of February 2027, and the next BOM freeze locks before Christmas. He is now writing the same long-term agreement for DP83TG720RWRHATQ1 (the gigabit version of the same family) and a parallel 5,000-piece line for Microchip's KSZ9131RNXC-TR as a dual-source for industrial machines that don't need the AEC-Q100 envelope.

A handful of automotive Ethernet PHY parts — known in the specs as 100BASE-T1 (100 Mbit single-pair), 1000BASE-T1 (1 Gbit single-pair), and 10BASE-T1S (10 Mbit multidrop) — used to be a quiet specialty corner that brokered between ADAS head units and zonal controllers. They are now a procurement story for industrial buyers too, because the same Texas wafer slots that pour out those PHYs also pour out the DP83822IFRHBT and DP83822HFRHBR that sit behind almost every PLC, every industrial gateway, and every factory 5G router. When the automotive side pulls 24-week capacity, the industrial side ends up on the same allocation line.

That is the news of late August 2026. TechInsights documented this on May 14, 2026 — automotive semiconductor lead times "climbed again in Q1 2026, reaching their highest level since Q3 2023" (TechInsights, May 14 2026). Sourceability's Q2 2026 lead-time report on July 14, 2026 confirmed the extension carried into the second quarter. Microchip's own Q3 FY2026 earnings call on February 9, 2026 told investors that the company's mix was "shifting toward networking and data center" — which, in plain language, means the silicon real estate is being consciously steered away from the marginal industrial 100-Mbit gigabit PHY line and toward the higher-margin server Ethernet, fiber, and SPE business (The Futurum Group, February 9 2026). SDxCentral reported on May 7, 2026 that Arista Networks "warns of long-term chip challenge," and a Broadcom link was implied in the analyst commentary.

This report covers the parts and lead-time windows, who is tight, who is still open, what is happening to industrial PHY prices, what we can ship today, and how to position a 12- to 26-week contract before Q4 closes. Data cutoff: August 22, 2026.

1. What the market signal looks like in numbers

Three threads converge on the 100BASE-T1 / 1000BASE-T1 story:

• Automotive semi lead times are at a 24-month high. TechInsights reported on May 14, 2026 that "automotive semiconductor lead times climbed again in Q1 2026, reaching their highest level since Q3 2023." The same report attributed much of the climb to MCU and power supply allocation, but the Ethernet PHY and serializer/deserializer buckets dragged the headline number higher. Sourceability's Q2 2026 report on July 14, 2026 carried the extension into Q2 without a clean reversal.
• The architecture shift toward zonal E/E is now real, not roadmap. Molex announced its next-generation HSAutoLink G automotive Ethernet connector on June 30, 2026 — explicitly addressing "rising ADAS/compute demands and zonal architectures" (PR Newswire, June 30 2026). Automotive IQ framed this as a "Domain vs Zonal Architecture" engineering shift in a piece on July 8, 2026. EE Times published "Automotive Ethernet and Time Sensitive Networking for Next Generation Vehicles" on July 27, 2026, the same week that Marvell reported networking/data-center mix shift on its earnings call. The zonal architecture requires each zone to talk to the central compute over 100BASE-T1 or 1000BASE-T1 — which is precisely why the single-pair Ethernet PHY volumes are accelerating exactly when the foundry allocation is getting tighter.
• New SPE silicon is arriving, but it confirms demand, not relief. Microchip announced its LAN878x and LAN888x single-pair Ethernet (SPE) transceivers on May 8, 2026 (Bisinfotech, May 8 2026); All About Circuits confirmed on May 20, 2026 that the parts "pack security and safety features" aimed at zonal-endpoint and edge-node designs. New part numbers usually raise prices for older variants on the same wafer — that is exactly the pattern we are seeing on DP83TC812.

A fourth, indirect thread reinforces the picture. Tom's Hardware reported on July 31, 2026 that Lumentum's CEO warned of "an impending bottleneck on critical material used for silicon photonics — fab and material shortfall already lags 30% below customer needs as co-packaged optics demand skyrockets." Photonics are a different category from copper Ethernet, but both ride on the same advanced-package substrate and back-end test capacity. When the back-end substrate is 30% below customer demand, every wafer that comes off the line ends up in a queue rather than on a shipping dock.

2. Which parts are tight, which are still available

We mapped this against our own catalog rows and direct channel observations. Six Ethernet PHY families carry the weight of the supply question right now.

What is still loose, at least for the moment:

• KSZ9021 series (Microchip) at the lower tier; these are older gigabit PHYs that some non-automotive customers will substitute for KSZ9131 when the newer part queues. They are not a one-to-one substitute — register maps and a few strap options differ — but for a clean gigabit industrial design they can replace KSZ9131 with a small firmware carry. We carry KSZ9021GQI and KSZ9021RLI as alternates.
• WIZnet W5500 and the W5500-series SPI-to-Ethernet MAC+PHY modules. These are not the same class as the TI/Microchip PHYs (W5500 integrates MAC+PHY on-chip and offloads TCP), but for budget industrial designs that don't need the 100/1000BASE-T1 envelope they are a working alternative and our catalog rows are stocked.
• DP83910AV and other legacy DP83910/DP83815/DP83816A parallel-bus PHYs. Not for new designs, but for legacy 10BASE-T maintenance/repair of installed PLC networks a buyer can still source small quantities in 8–12 weeks.

What is tight in a way that matters operationally:

• DP83TC812 in automotive temp grade. Two things are happening in parallel. First, allocation against the SDV/zonal demand ramp. Second, allocation pulled forward by the imminent TSMC wafer pricing reset for 2027. Buyers that don't pre-book now are looking at a 32-week or longer queue from January 2027 onward.
• DP83TG720 (the gigabit version). The 1000BASE-T1 market is essentially a TI/Marvell/NXP three-horse race in 2026; Marvell's 88Q4362 and NXP's TJA1101B/SJA1105 are not always direct pin-to-pin swaps for TI, which means even dual-sourcing leaves a 4 to 8-week qualification delta. In our catalog, the 1000BASE-T1 line is narrow — DP83TG720 is the main automotive-gigabit row.
• DP83822HFRHBR fiber SKU. The lower-cost DP83822IFRHBT copper-only part is still moving at 18–22 weeks; the HFRHBR fiber variant that lines include for industrial fiber-to-the-cabinet and 5G-fronthaul routers has stretched beyond that window because the fiber PHY is also being pulled into optical-line-terminator designs.

3. What we carry — concrete catalog rows and how to source them

All six Ethernet PHY parts above are live catalog rows verified by the icboms supply-chain desk on August 22, 2026. Front-end page paths follow the standard format on icboms.com.

TI DP83TC812SRHARQ1 (100BASE-T1, AEC-Q100, automotive) — full/half duplex, 36-VQFN (6×6) wettable flank, 2.97–3.63 V supply, reference price $6.30 at qty 1, ladder to $5.43 at qty 25 and continuing down through volume breaks. Sourced through TI's authorized franchised channel, with batch verification on every delivery (date code, lot trace, and AEC-Q100 documentation). On the product page you can pull the latest factory confirmation and direct-request a 24-week LTA quote at the standard MOQ of 1 reel (2,500 pieces). Industrial buyers who don't need automotive temp grade can cross-check against KSZ9031RNXIC-TR on industrial temperatures, but plan a re-qualification window.

TI DP83TG720RWRHATQ1 (1000BASE-T1 gigabit, AEC-Q100, automotive) — IEEE 802.3, 1 Gbps, full/half duplex, 36-VQFN (6×6), reference price $12.60, ladder to $11.10 at qty 25 and $10.55 at qty 100. This is the part buyers should not assume can be cross-referenced against a Marvell or NXP competitor on a one-day swap. The 1000BASE-T1 ecosystem is fragmented, and the PHY-to-MAC interface requirements (RGMII delay, SGMII compatibility for SoC-side MACs) need a SPEC-level review before a sub is qualified.

TI DP83822IFRHBT (10/100 industrial Ethernet PHY, MII/RMII) — 32-VQFN (5×5), 1.71–3.45 V supply, reference $4.42, ladder to $3.97 at qty 10, $3.75 at qty 25, and $3.25 at qty 100. This is the workhorse for PLC backplanes, building-automation gateways, and the 5G small-cell S1/N2 interface — wherever a 10/100 link is enough. Plan for 18–22 weeks on small qty and negotiate a 26-week LTA on thousand-piece-and-up orders.

TI DP83822HFRHBR (10/100 industrial Ethernet PHY, fiber-capable) — 32-VQFN (5×5), same dual-MAC MII/RMII interface, 1.71–3.45 V supply, reference $6.61, ladder to $5.97 at qty 10 and $5.69 at qty 25. Use this part when the design must reach a 100BASE-FX fiber segment through an external fiber transceiver — the on-chip termination and clocking is tuned for that case.

Microchip KSZ9031RNXIC-TR (industrial gigabit Ethernet PHY, RGMII) — 48-VFQFN with exposed pad, 1.8/2.5/3.3 V supply, industrial temp grade −40 to +85 °C, reference $4.72. Used widely in industrial PC motherboards and gateway designs. Plan for 14–22 weeks. This is the most likely dual-source for DP83822 if your design only needs a gigabit PHY and can run RGMII; for 10/100-only designs, KSZ9031 is overkill.

Microchip KSZ9131RNXC-TR (industrial gigabit Ethernet PHY, RGMII, current generation) — 48-VQFN, reference $3.79, generally the lowest-cost pin-compatible upgrade from KSZ9031 for new designs. Plan for 16–24 weeks. Like KSZ9031, this is an industrial-grade alternative to the automotive TI PHYs only if your design lives at −40 to +85 °C.

A practical sourcing note: if you are designing an industrial product today and you don't need AEC-Q100, the KSZ9031/KSZ9131 path gives you 14–24 weeks while DP83TC812/DP83TG720 queues. If you need the AEC-Q100 envelope, you must commit to the TI 24–40-week LTA and run a parallel pre-qualification of KSZ9031/KSZ9131 hardware-validated on industrial temperature, so that when the zonal programs lock down, you are not stuck on a 36-week allocation if your product is a non-automotive spin-off.

4. The foundry and packaging story behind the queue

The reason industrial buyers care about an automotive-spec row is not because industrial robots are about to start talking single-pair Ethernet. It is because of three structural facts.

First, the silicon. Both the TI and Microchip Ethernet PHY families are built on mature 180-nm and 130-nm CMOS process nodes — the kind of trailing-edge nodes that everyone says have "plenty of capacity." But capacity at the trailing edge is being absorbed by automotive-grade qualification, and that absorbs a 9 to 14 month window of die-bank inventory that older industrial customers used to draw from. A 130-nm fab running AEC-Q100-qualified lots does not flex easily to industrial temp-grade runs; the documentation trail, the reliability lot, the burn-in board, the statistical sample — all that has to be re-baselined.

Second, the package. The DP83TC812 and DP83TG720 are 36-VQFN with wettable flanks — a packaging format that is now the standard for zonal-architecture ECU boards because it exposes the side metallization for AOI optical inspection. Wettable-flank packages went from optional to mandatory across 2023–2025 as more OEMs adopted bottom-terminated-component PCB inspection; OSAT lines that do wettable flank are now booked 22–36 weeks out for the lower-volume packages. The 36-VQFN (6×6) wettable-flank mold is not a high-volume commodity; it is a specialty slot in a few ASEAN back-end test houses.

Third, the back-end test. Tom's Hardware's July 31, 2026 reporting on Lumentum's silicon-photonics material bottleneck is a useful adjacent proxy. Photonics are not Ethernet PHYs, but they share substrate and back-end test capital. When a CEO is willing to publicly state a 30% customer-needs shortfall on critical material, you can assume the back-end of the line is operating tight even where front-end capacity seems comfortable.

Fourth, the rationalization of internal capacity. Microchip's Q3 FY2026 earnings call commentary on February 9, 2026 — paraphrased by The Futurum Group — explicitly framed the company's strategic tilt toward "networking and data center" silicon. That is the language of a supplier that is going to load its fab on LAN878x/LAN888x SPE (May 8 2026, Bisinfotech) and on higher-margin data-center controllers, not on legacy industrial gigabit PHYs. Long-term Microchip customers of KSZ9031 and KSZ9131 should expect incremental allocation pressure that mirrors TI's.

Marvell, the third big SPE silicon supplier, has its own rationalization story in 2026 — its networking/data-center mix shift was widely reported around its Q1 FY2027 call in May/June, and the TSN-capable Marvell switch silicon is itself an active story for industrial buyers (EE Times, July 27 2026).

5. How to buy in this market — six concrete moves

1. Lock a 24- to 32-week LTA on DP83TC812SRHARQ1 and DP83TG720RWRHATQ1 now. Q4 2026 allocation windows open in mid-September; getting the contract in place before allocation opens gives you a confirmed first-quarter 2027 slot. Standard MOQ is one reel (2,500 pieces); most franchised channels allow letter-of-credit or 30/70 terms on LTA bookings. If your design is zonal-architecture-adjacent but does not yet have a confirmed end-customer, book anyway — the lead time you secure will trade favorably in the secondary market at 5–8% above your booking price if you do end up with overage.

2. For non-automotive designs, dual-source with KSZ9031RNXIC-TR (industrial gigabit) or KSZ9131RNXC-TR (industrial gigabit, current generation) before November. Microchip's strategic mix tilt toward networking/data-center, flagged on its Q3 FY2026 call in February 2026, will tighten the industrial gigabit line by Q4 even if the automotive zonal push doesn't grab it. The 14–22-week window now is the cheapest moment to confirm a 5,000-piece Q1 2027 run.

3. Validate the design for 100BASE-T1S multidrop separately, on a 6-month horizon. Microchip's 10BASE-T1S endpoint devices (announced November 2025, refreshed coverage in 2026) are going to be the third vector of pressure on the single-pair Ethernet line. If your industrial roadmap runs to sensor-bus, edge, or building-automation nodes, plan now to characterize a 10BASE-T1S sub and confirm a second source. The 10BASE-T1S multidrop standards feature reduces harness weight by replacing point-to-point 100BASE-T1 with a single twisted pair shared by up to eight nodes.

4. Audit every shipment that comes through the spot market for date-code and lot-trace. With 24–32-week allocation on the popular TI and Microchip PHYs, the spot market will increasingly show 2025-witnessed reels with questionably-clean dry-pack seals. Watch for mismatched lot codes between the reel label and the inner MSL bags, missing or duplicated MPN strings on the carrier tape, and — most importantly — reels labeled as "cut tape" when the lot is actually a full reel that was relabeled for easier shipment. Insist on the franchised channel paper trail (Authorized Distributor Agreement evidence, manufacturer C of C, RoHS/REACH declaration).

5. Document any non-TI automotive-temp alternative on an MBSE-style qualification table before you have to act. A standalone qualification packet — thermal derating, AEC-Q100 grade mapping, MTBF calculation per Telcordia SR-332 — lets your engineering team swap TI automotive silicon for NXP TJA1101B or Marvell 88Q4362 with a 4 to 6 week carry-over instead of a 16-week re-characterization. Don't wait until allocation forces the conversation.

6. For industrial machine builders — and this is the bigger structural lesson — treat ethernet, FPGA, and DC-DC modules as one allocation family. The same foundry pivot toward SDV/AI infrastructure is pulling DCDC modules, FPGA fabric, and physical-layer silicon in the same direction. We covered Google's, Microsoft's, and Nvidia's August 13 2026 endorsement of 800V DC for AI datacenters earlier this month; TrendForce reported on August 21 2026 that STMicroelectronics' third 2026 price hike will land on August 23 with power-device lead times at 52 weeks. Pulling these threads together: if your industrial panel PC or AGV needs a TI PHY + a ST power supply + a Lattice FPGA, you are now exposed on three foundry-priority axes at once. Consolidate your RFQ schedule so you can negotiate all three against the same channel.

Data notes

Data cutoff: August 22, 2026. Lead-time windows, price ladders, and allocation estimates are directional sourcing-desk observations taken from franchised-channel confirmations during the week of August 18 through August 22, 2026 — not quotes. Treat all figures as planning data, not contractual lead times.

Sources (publishers, not URLs, are referenced in the body): TechInsights (May 14, 2026 — Automotive Semiconductor Lead Times Q1 2026), Sourceability (July 14, 2026 — Q2 2026 Lead Time Report), PR Newswire / Molex (June 30, 2026 — HSAutoLink G launch), EE Times (July 27, 2026 — Automotive Ethernet and TSN for Next-Generation Vehicles), The Futurum Group (February 9, 2026 — Microchip Q3 FY2026 earnings call recap), SDxCentral (May 7, 2026 — Arista long-term chip challenge), Tom's Hardware (July 31, 2026 — Lumentum silicon-photonics material bottleneck), Microchip / Bisinfotech (May 8, 2026 — LAN878x / LAN888x SPE transceiver launch), All About Circuits (May 20, 2026 — Microchip 100/1000BASE-T1 SPE PHY packaging and security features), Automotive IQ (July 8, 2026 — Domain vs Zonal Architecture), ELE Times (March 16, 2026 — Ethernet in software-defined vehicles), Stock Titan (January 5, 2026 — TI CES 2026 new car chips for AI and radar), Investing News Network (March 5, 2026 — TI / NVIDIA collaboration on physical AI sensor fusion), TrendForce (August 21, 2026 — STMicroelectronics third 2026 price hike and 52-week power-device lead time).

Closing

Most catalogs we surveyed this week still list the TI and Microchip Ethernet PHYs at older stable prices. That stability is the historical quote, not the live one. Open any of the six catalog rows listed above (DP83TC812SRHARQ1, DP83TG720RWRHATQ1, DP83822IFRHBT, DP83822HFRHBR, KSZ9031RNXIC-TR, KSZ9131RNXC-TR) and request a 24-week factory-confirmed quote today. The factory queue is moving roughly one week longer every three weeks right now, and Q4 LTAs lock in mid-September.

Brand: Texas Instruments, Microchip. Services: 100BASE-T1 / 1000BASE-T1 / 10BASE-T1 / 10/100 / Gigabit PHY sourcing for industrial and automotive buyers; LTA structuring; second-source qualification packets; batch verification on every delivery; counterfeit and dry-pack audit on spot-market reels. Applicable buyers: EV Tier-1/ECU integrators, ADAS and zonal-architecture design teams, factory-automation and PLC buyers, industrial IoT gateway vendors, 5G fronthaul and small-cell ODM/EMS, robotics and AGV platform teams. Languages: 中文 · English · Русский · Español · العربية.