PMC-Sierra
PMC-Sierra was a Canadian-American fabless semiconductor company that developed chips for communications, storage, optical networking, printing, and embedded-computing equipment.
Last updated August 31, 2026
Overview
PMC-Sierra was a global fabless semiconductor company whose products were designed for communications infrastructure, optical transport, storage systems, printers, and embedded computing. The business was ultimately headquartered in Burnaby, British Columbia, although its origins combined a California semiconductor company with a Canadian networking-chip venture. It ceased to exist as an independent company after Microsemi completed its acquisition on January 15, 2016; Microchip Technology subsequently acquired Microsemi on May 29, 2018. The company’s history began with Sierra Semiconductor, founded in San Jose, California, in 1984 by James Diller. Sierra received early backing from Sequoia Capital and went public in 1991. A second strand of the company’s development came from Pacific Microelectronics Centre, or PMC, which had been spun out of Microtel Pacific Research, the research arm of BC TEL, to develop integrated circuits for asynchronous transfer mode and SONET networking. With investment from Sierra Semiconductor, PMC was established as a private company in 1992 and became Sierra’s wholly owned, independently operated subsidiary in 1994. PMC’s strongest early technical success was in optical networking. In 1995, it introduced OC-12 S/UNI transceiver chips capable of supporting 622 Mbit/s optical links. The technology helped establish the company as a significant supplier of optical-networking chipsets and gave it an advantage in the emerging high-speed telecom infrastructure market. The company later broadened its portfolio to include metro-access, fiber-to-the-home, Ethernet-over-SONET/SDH, optical transport networking, wireless infrastructure, and customer-premises equipment. The company also made a strategic shift away from consumer and personal-computer modem products. In August 1996, Sierra Semiconductor announced that it would leave the PC modem chipset business, restructure several non-networking activities, and concentrate on networking. The restructuring included approximately 150 redundancies. Sierra then expanded its Ethernet capabilities through the acquisition of Bipolar Integrated Technology in late 1996 and acquired Integrated Telecom Technology in 1998. In June 1997, PMC overtook its former parent in corporate identity and the company adopted the name PMC-Sierra, while moving its headquarters to Burnaby. PMC-Sierra operated as a fabless semiconductor designer. It developed and tested devices while outsourcing wafer fabrication, assembly, and related manufacturing activities to third-party suppliers. Its customers and ecosystem partners included major equipment manufacturers such as HP, EMC, Huawei, Cisco, Alcatel-Lucent, Fujitsu, Hitachi, Mitsubishi, ZTE, and Juniper. The company’s products were generally components or system-on-chip devices sold to manufacturers of networking, storage, telecommunications, and office-equipment systems rather than directly to consumers. Storage became a major business area. PMC-Sierra supplied SAS and SATA controllers and interconnect devices, RAID adapters, Fibre Channel products, and storage-network components. Following its acquisition of Adaptec’s channel-storage business, it marketed SAS/SATA RAID adapters under the Adaptec by PMC name. The acquisition of IDT’s enterprise flash-controller business in 2013 strengthened its non-volatile-memory strategy, and the company introduced the Flashtec line of flash-related products in 2014. Communications remained the other central pillar. The portfolio covered passive optical-network and fiber-to-the-home access, metro transport, optical transport networking, wireless backhaul, base-station equipment, and Ethernet infrastructure. The company also developed MIPS-based network processors and UniTRX radio-frequency integrated circuits for wideband wireless radio modules supporting frequency ranges from 400 MHz to 4 GHz and multiple cellular standards. Its DIGI-G4 optical-transport processor targeted 400G line-card applica…
History
PMC-Sierra emerged from the combination of Sierra Semiconductor in California and Pacific Microelectronics Centre in British Columbia. Sierra Semiconductor was founded in San Jose in 1984 by James Diller, received early investment from Sequoia Capital, and became a public company in 1991. PMC originated within Microtel Pacific Research, the research arm of BC TEL, where it worked on integrated circuits for asynchronous transfer mode and SONET networking. With Sierra Semiconductor’s investment, PMC became a private company in 1992 and was made a wholly owned but independently operated subsidiary of Sierra in 1994. The Canadian operation achieved an important breakthrough in 1995 with OC-12 S/UNI transceiver chips for 622 Mbit/s optical links. This product helped PMC establish a strong position in optical networking and supported its expansion into communications infrastructure. Its later portfolio covered metro access and transport, fiber-to-the-home and passive optical networks, Ethernet over SONET/SDH, optical transport networking, wireless backhaul, base-station equipment, customer-premises equipment, and embedded network processing. In 1996, Sierra Semiconductor decided to exit the personal-computer modem chipset market. The company announced a restructuring, focused its remaining non-networking activities, and eliminated approximately 150 positions. It acquired Bipolar Integrated Technology in late 1996 to enter Ethernet and related communications markets. The headquarters moved to Burnaby, and in June 1997 the organization adopted the PMC-Sierra name after PMC had become more prominent than its former parent. The company acquired Integrated Telecom Technology in 1998 for approximately $55 million in cash and stock, adding further communications technology. PMC-Sierra was organized as a fabless semiconductor business. It designed and tested chips, while third-party manufacturers handled wafer fabrication, assembly, and other production functions. The company sold more than 250 semiconductor devices to equipment manufacturers serving communications operators and enterprise customers. Reported customers and industry relationships included HP, EMC, Huawei, Cisco, Alcatel-Lucent, Fujitsu, Hitachi, Mitsubishi, ZTE, and Juniper. Storage became increasingly important alongside communications. PMC-Sierra developed SAS and SATA controllers and interconnects, RAID adapters, Fibre Channel controllers, and other storage-network products. Its acquisition of Adaptec’s channel-storage business led to products sold as Adaptec by PMC. In 2006, Passave was acquired to strengthen system-on-chip products for fiber-to-the-home access. Wintegra was acquired in 2010 for approximately $240 million, adding network-processing capabilities and engineering resources in Israel and the United States. In 2013, PMC-Sierra acquired IDT’s enterprise flash-controller business and subsequently introduced the Flashtec line in 2014. The company also supplied discrete and system-on-chip devices for laser and multifunction printers. In wireless infrastructure, its MIPS-based network processors supported backhaul and its UniTRX radio-frequency integrated circuits targeted wideband radio modules supporting multiple cellular technologies, including GSM, CDMA2000, WCDMA, and LTE. The DIGI-G4 OTN processor represented a later-generation optical-transport effort aimed at 400G line cards and received a Lightwave Innovation Award in 2015. PMC-Sierra underwent repeated workforce reductions during the semiconductor downturns and periods of strategic restructuring. The source history records reductions in 2001, 2003, 2005, 2006, two rounds in 2007, and a larger reduction in July 2015. In late 2015, Skyworks Solutions and Microsemi both pursued the company. Microsemi announced an acquisition agreement on November 24, 2015, and completed the transaction on January 15, 2016 through Lois Acquisition. Microchip Technology acquired Microsemi on May 29, 2018, placing PMC-Sierra’s acquired technologies within the Microchip corporate group.
- 2018Microchip acquires Microsemi
Microchip Technology completed its acquisition of Microsemi, the company that had acquired PMC-Sierra.
- 2016Microsemi completes acquisition
Microsemi completed its acquisition of PMC-Sierra through Lois Acquisition, ending the company’s independent existence.
- 2015DIGI-G4 earns industry recognition
The DIGI-G4 optical transport processor received a Lightwave Innovation Award for its support of 400G optical networking applications.
- 2014Flashtec line is introduced
PMC-Sierra introduced Flashtec products for non-volatile-memory and enterprise flash applications.
- 2013IDT enterprise flash-controller business is acquired
The acquisition expanded PMC-Sierra’s enterprise storage and flash-controller capabilities.
- 2010Wintegra is acquired
PMC-Sierra acquired Wintegra, adding network processors and engineering operations in Israel and the United States.
- 2006Passave is acquired
The company acquired Passave to expand its fiber-to-the-home system-on-chip business.
- 1998Integrated Telecom Technology is acquired
PMC-Sierra acquired Integrated Telecom Technology in a cash-and-stock transaction valued at approximately $55 million.
- 1997Company adopts the PMC-Sierra name
After PMC overtook its former parent in corporate identity, the company changed its name to PMC-Sierra and moved its headquarters to Burnaby.
- 1996Exit from PC modem chipsets
Sierra Semiconductor announced that it would leave the personal-computer modem chipset market and concentrate on networking products.
- 1995OC-12 optical transceiver breakthrough
PMC introduced OC-12 S/UNI transceiver chips supporting 622 Mbit/s optical networking links.
- 1994PMC becomes a Sierra subsidiary
PMC became a wholly owned, independently operated subsidiary of Sierra Semiconductor.
- 1992Pacific Microelectronics Centre is established as an independent company
PMC was spun out of Microtel Pacific Research with Sierra Semiconductor investment and focused on networking semiconductors.
- 1991Sierra Semiconductor goes public
Sierra Semiconductor became a publicly traded company.
- 1984Sierra Semiconductor is founded
James Diller founded Sierra Semiconductor in San Jose, California. The company received funding from Sequoia Capital during its early development.
Products and positioning
A specialist supplier of high-performance fabless semiconductors for communications infrastructure, optical transport, enterprise storage, wireless equipment, and embedded systems. PMC-Sierra primarily sold components and system-on-chip products to equipment manufacturers and network suppliers rather than to consumers.
OC-12 S/UNI transceiversOptical networking1995
PMC’s OC-12 S/UNI transceiver chips supported 622 Mbit/s optical links and helped establish the company as an important supplier of optical-networking integrated circuits. Introduced in 1995, the devices addressed SONET and related telecommunications infrastructure and were part of the company’s early expansion beyond general semiconductor products.
Adaptec by PMCStorage controllers and RAID adapters
Adaptec by PMC was the branding used for the channel-storage business acquired from Adaptec. The portfolio included SAS and SATA RAID adapters and related storage-controller products for servers, enterprise systems, and storage networks. It extended PMC-Sierra’s storage presence from individual controller chips into recognizable system components sold to equipment manufacturers and enterprise channels.
FlashtecEnterprise flash controllers2014
Flashtec was PMC-Sierra’s line of flash-controller and non-volatile-memory products developed after the acquisition of IDT’s enterprise flash-controller business. The products targeted high-performance enterprise storage and solid-state-memory systems, complementing the company’s established SAS, SATA, RAID, and Fibre Channel offerings.
DIGI-G4Optical transport networking processor2015
DIGI-G4 was an optical transport networking processor designed for the move toward 400G line cards in switched metro optical networks. PMC-Sierra described it as a dense single-chip 4-by-100G OTN processor with reduced power per port compared with the preceding generation. The product received a Lightwave Innovation Award in 2015.
UniTRXWireless infrastructure RF integrated circuits
UniTRX comprised highly integrated, low-power radio-frequency integrated circuits for wideband radio modules used in wireless infrastructure. The devices covered frequencies from 400 MHz to 4 GHz and were designed for macro base-station transceivers supporting technologies including MC-GSM, cdma2000, WCDMA, and LTE.
SAS, SATA, RAID, and Fibre Channel productsEnterprise storage semiconductors
PMC-Sierra supplied a broad family of storage controllers and interconnect products for SAS and SATA systems, RAID controllers, Fibre Channel equipment, and storage networks. These components were sold primarily to manufacturers of servers, disk arrays, and enterprise storage systems rather than as consumer-facing products.
Printer semiconductorsPrinter and multifunction-printer components
The company developed discrete semiconductors and system-on-chip devices for laser printers and multifunction printers. These products formed a smaller business alongside PMC-Sierra’s principal communications and storage activities and supplied electronics manufacturers integrating printing functionality into office equipment.
Flagship businesses
- Adaptec by PMC SAS/SATA RAID adapters
- Flashtec flash-controller products
- DIGI-G4 optical transport processor
- UniTRX wireless radio-frequency integrated circuits
- OC-12 S/UNI optical transceiver chipsets
Brand decisions
- 20152015 restructuringStrategy
PMC-Sierra undertook restructuring amid pressure in the semiconductor and communications markets.
What changed. The company eliminated roughly 200 positions in July 2015.
Aftermath. The restructuring occurred shortly before the company became the subject of competing acquisition efforts by Skyworks Solutions and Microsemi.
- 2015Agreement to be acquired by MicrosemiM&A
Skyworks Solutions and Microsemi were both attempting to acquire PMC-Sierra during the second half of 2015.
What changed. Microsemi announced on November 24, 2015 that it had entered into an agreement to acquire PMC-Sierra.
Aftermath. Microsemi completed the transaction on January 15, 2016 through its Lois Acquisition subsidiary, ending PMC-Sierra’s independent corporate existence.
- Skyworks Solutions — Skyworks Solutions was reported as another bidder in the acquisition contest, but the source does not provide a final reaction.
- 2013Acquisition of IDT’s enterprise flash-controller businessM&A
PMC-Sierra was broadening its storage portfolio beyond traditional SAS, SATA, RAID, and Fibre Channel components.
What changed. The company acquired IDT’s enterprise flash-controller business.
Aftermath. The transaction provided the foundation for the Flashtec line introduced in 2014 and strengthened PMC-Sierra’s position in enterprise solid-state storage.
- 2010Acquisition of WintegraM&A
PMC-Sierra sought to strengthen its communications-processing portfolio for networking infrastructure.
What changed. The company acquired Wintegra, a network-processor business with substantial development operations in Israel and Texas.
Aftermath. PMC-Sierra added Wintegra’s network-processing technology and approximately 165 employees to its communications activities.
Acquisition price. $240 million (2010)
- 2006Acquisition of PassaveM&A
Passave developed system-on-chip semiconductors for fiber-to-the-home access, an area aligned with PMC-Sierra’s communications strategy.
What changed. PMC-Sierra acquired Passave in a stock-for-stock transaction.
Aftermath. The transaction expanded PMC-Sierra’s access-networking portfolio and added Passave operations in Boston and Israel.
Approximate transaction value. $300 million (2006)
- 1996Exit from the personal-computer modem chipset marketStrategy
Sierra Semiconductor was repositioning itself toward networking products and away from the increasingly competitive personal-computer modem chipset business.
What changed. The company announced that it would leave the PC modem market, restructure other non-networking activities, and concentrate resources on networking.
Aftermath. The decision included approximately 150 redundancies and preceded the company’s stronger emphasis on optical, Ethernet, access, and other communications semiconductors.
Recent events
- 2016PMC-Sierra completes acquisition by Microsemi
Microsemi completed its acquisition of PMC-Sierra through its subsidiary Lois Acquisition, ending PMC-Sierra’s existence as an independent public semiconductor company.
M&A - 2015Microsemi announces agreement to acquire PMC-Sierra
After a bidding contest involving Skyworks Solutions and Microsemi, Microsemi announced an agreement to acquire PMC-Sierra in November 2015.
M&A - 2015DIGI-G4 receives a Lightwave Innovation Award
PMC-Sierra’s DIGI-G4 optical transport processor received a Lightwave Innovation Award for its capabilities in supporting the transition to 400G optical line cards.
Product launchOther - 2015PMC-Sierra announces restructuring and workforce reduction
The company reduced its workforce by roughly 200 employees in July 2015 as part of a restructuring program.
Other - 2014PMC-Sierra introduces Flashtec products
The company introduced its Flashtec line after acquiring IDT’s enterprise flash-controller business, extending its storage portfolio toward high-performance non-volatile memory applications.
Product launch - 2013PMC-Sierra acquires IDT enterprise flash-controller business
PMC-Sierra acquired IDT’s enterprise flash-controller business, reinforcing its storage and solid-state-memory product portfolio.
M&AProduct generation - 2010PMC-Sierra acquires Wintegra
PMC-Sierra acquired Wintegra for approximately $240 million, adding network processors and related communications technology, with development operations centered in Israel and the United States.
M&A - 2006PMC-Sierra acquires Passave
PMC-Sierra acquired Passave in a stock-for-stock transaction valued at approximately $300 million. Passave specialized in system-on-chip semiconductors for fiber-to-the-home access.
M&A
Sources
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