TL;DR · 30-second read
The Short Version
The giant computers behind artificial intelligence spend a growing share of their electricity just moving data between chips, not doing the math.
Semtech, a California chipmaker, builds the small parts that push those signals down cables and turn them into light and back. It is now paying its long-time contract factory, Tower Semiconductor, to set aside production space for it in the United States, Israel and Japan.
The surprise: the artificial intelligence boom is not only a scramble for famous high-end processors. Even the plainer chips that connect them are being booked under multi-year deals.
Tower Semiconductor and Semtech announced on October 13, 2026 an expanded multi-year agreement under which Semtech will invest in securing dedicated silicon germanium (SiGe) manufacturing capacity at Tower’s fabs in the United States, Israel and Japan. The capacity supports Semtech’s signal-integrity chips, including amplifiers, drivers and equalizers used in optical and copper links inside AI data centers, at link speeds from 800G and 1.6T today toward 3.2T.
Tower filed the joint announcement with US regulators in a 6-K the same day. The companies did not disclose the size of Semtech’s investment, the wafer volumes reserved or the agreement’s length beyond “multi-year.” In a separate 6-K, Tower said it will report third-quarter 2026 results on November 2.
Executive Summary
Semtech and Tower have worked together for 20 years, and Semtech’s high-speed analog parts already run on Tower’s SiGe process. What changes now is the commercial structure. Semtech is no longer only buying wafers as it needs them. Under the expanded agreement it will invest to secure capacity dedicated to its products, spread across three regions for what both companies describe as supply resilience and geographic diversification.
The announcement matters because it reaches a part of the AI supply chain that gets little attention. Most discussion of AI chip supply focuses on leading-edge logic: accelerators and the digital signal processors built at the most advanced nodes. Every optical or copper link between those accelerators also needs an analog front end, the circuitry that physically drives and receives the signal. Semtech makes those parts on a specialty process at a specialty foundry, and it is now committing money to guarantee its share of that foundry’s output.
The release frames the demand case in terms of power. It says AI’s next constraint is power, that a growing share of it is spent moving data rather than computing it, and that each step from 800G to 1.6T to 3.2T raises the requirements for bandwidth, reach and power per bit.
Why a Link Chip Needs Its Own Fab
An optical transceiver, the pluggable module that converts electrical signals to light and back, contains more than a laser and a digital chip. It also holds a transimpedance amplifier (TIA), which turns the faint current from a photodetector into a usable voltage, and a modulator or laser driver, which pushes the outgoing signal hard and cleanly enough to survive the trip. These are analog circuits. Their performance depends on transistor speed and noise rather than on how many logic gates fit on a die. Silicon germanium, which adds germanium to silicon transistors to make them faster, is a long-standing process choice for this kind of high-frequency analog work. It is also a different manufacturing line from the leading-edge digital processes that dominate AI supply headlines.
The speed roadmap raises the stakes for these parts. Tower’s 6-K describes each step from 800G to 1.6T to 3.2T as raising the requirements for bandwidth, reach and power per bit, and as increasing the importance of the high-speed analog front end. Semtech’s recent ECOC 2026 award was for a 224 Gbps-per-lane TIA family built on Tower’s SiGe. That per-lane rate shows how much performance these analog parts must now deliver. Several of the architectures Semtech lists, including linear pluggable optics (LPO) and linear receive optics (LRO), are designed to remove or reduce the power-hungry digital signal processor in the module. That design shifts more of the signal-conditioning job onto the analog components Tower manufactures.
Paying for Dedicated Capacity Is the Operational Signal
The core of this announcement is the commitment. According to the 6-K, Semtech “will invest in securing dedicated silicon germanium (SiGe) capacity at Tower.” Semtech CEO Hong Hou tied that directly to supply planning: “Meeting that demand requires long-term capacity planning and commitment with our manufacturing partners.” A chip designer does not usually spend its own money to reserve capacity at a 20-year supplier unless it judges that buying wafers as needed carries too much supply risk for the volumes it expects.
That is the sense in which AI interconnect planning has reached the analog fab. Neither company says SiGe capacity is short today, and the release should not be read as evidence of a shortage. It points instead to “strong design wins” and demand “expected to grow across a broadening base of customer programs.” The operational conclusion is narrower and better supported. For at least one major supplier of AI link components, securing specialty analog wafer capacity has become a deliberate investment and a multi-year commitment, the kind of arrangement more commonly associated with leading-edge logic.
The people affected are those downstream of Semtech’s parts: transceiver and active-copper-cable makers, and the data center operators deploying 1.6T networks. For them, the availability of the analog front end now depends partly on how much capacity Semtech has locked in at Tower. The question for other Tower customers in data center optics is whether they will need similar commitments to secure their own supply.
What Each Side Gets, and What Is Still a Claim
For Semtech, the main benefits are assurance and geography. The capacity spans Tower’s fabs in the United States, Israel and Japan, so a disruption at one site need not halt supply of a product line. Semtech also positions its portfolio across both media in the data center, with copper links within the rack and optical links across the facility. Its active copper cable and linear equalizer products give it exposure if short-reach copper persists longer than some optics-first forecasts assume.
For Tower, a customer-funded capacity commitment adds visibility in a high-growth segment and ties a key customer to its multi-generation technology roadmap. Tower CEO Russell Ellwanger described the partnership as ensuring “a continual expansion of our already leading market share in optical transceiver connectivity.” The release offers no market-share figures to support that statement, so it should be read as the company’s characterization. Tower’s third-quarter results on November 2 are the first chance to see whether data center demand appears in the numbers.
Background
Tower Semiconductor, based in Migdal Haemek, Israel, describes itself as the leading foundry of high-value analog semiconductor solutions. It manufactures chips designed by other companies on specialty processes, including SiGe, silicon photonics (SiPho), BiCMOS and power management. It owns one 200mm fab in Israel and two in the US, operates two fabs in Japan (200mm and 300mm) through its 51% stake in TPSCo, and shares a 300mm facility in Agrate, Italy with STMicroelectronics.
Semtech, based in Camarillo, California, supplies high-performance semiconductors for AI data center networking and Internet of Things devices. Its data center products cover both optical links across a facility and copper links within a rack, a category growing as AI clusters move toward 1.6T and 3.2T network speeds. Source: Tower Semiconductor, Semtech Expand Partnership to Secure AI Chip Capacity (MarketScreener), coverage of the expanded SiGe capacity agreement for AI data center interconnects. Primary sources: Tower Semiconductor Form 6-K, October 13, 2026: Tower Semiconductor and Semtech Expand SiGe Partnership to Scale Power-Efficient Analog Connectivity for Data Centers; Tower Semiconductor Form 6-K, October 13, 2026: Tower Semiconductor Announces Third Quarter 2026 Financial Results and Conference Call.Sources