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 October 14, 2026
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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.
- 2018
Microchip acquires Microsemi
[1]Microchip Technology completed its acquisition of Microsemi, the company that had acquired PMC-Sierra.
- 2016
Microsemi completes acquisition
[1]Microsemi completed its acquisition of PMC-Sierra through Lois Acquisition, ending the company’s independent existence.
- 2015
DIGI-G4 earns industry recognition
[1]The DIGI-G4 optical transport processor received a Lightwave Innovation Award for its support of 400G optical networking applications.
- 2014
Flashtec line is introduced
[1]PMC-Sierra introduced Flashtec products for non-volatile-memory and enterprise flash applications.
- 2013
IDT enterprise flash-controller business is acquired
[1]The acquisition expanded PMC-Sierra’s enterprise storage and flash-controller capabilities.
- 2010
Wintegra is acquired
[1]PMC-Sierra acquired Wintegra, adding network processors and engineering operations in Israel and the United States.
- 2006
Passave is acquired
[1]The company acquired Passave to expand its fiber-to-the-home system-on-chip business.
- 1998
Integrated Telecom Technology is acquired
[1]PMC-Sierra acquired Integrated Telecom Technology in a cash-and-stock transaction valued at approximately $55 million.
- 1997
Company adopts the PMC-Sierra name
[1]After PMC overtook its former parent in corporate identity, the company changed its name to PMC-Sierra and moved its headquarters to Burnaby.
- 1996
Exit from PC modem chipsets
[1]Sierra Semiconductor announced that it would leave the personal-computer modem chipset market and concentrate on networking products.
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.
Optical networking · 1995
OC-12 S/UNI transceivers
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.
Storage controllers and RAID adapters
Adaptec by PMC
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.
Enterprise flash controllers · 2014
Flashtec
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.
Optical transport networking processor · 2015
DIGI-G4
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.
Wireless infrastructure RF integrated circuits
UniTRX
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.
Enterprise storage semiconductors
SAS, SATA, RAID, and Fibre Channel products
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 and multifunction-printer components
Printer semiconductors
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.
Brand decisions
2015
2015 restructuringStrategyBackground
PMC-Sierra undertook restructuring amid pressure in the semiconductor and communications markets.
Action taken
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.
2015
Agreement to be acquired by MicrosemiM&ABackground
Skyworks Solutions and Microsemi were both attempting to acquire PMC-Sierra during the second half of 2015.
Action taken
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.
2013
Acquisition of IDT’s enterprise flash-controller businessM&ABackground
PMC-Sierra was broadening its storage portfolio beyond traditional SAS, SATA, RAID, and Fibre Channel components.
Action taken
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.
2010
Acquisition of WintegraM&ABackground
PMC-Sierra sought to strengthen its communications-processing portfolio for networking infrastructure.
Action taken
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)
2006
Acquisition of PassaveM&ABackground
Passave developed system-on-chip semiconductors for fiber-to-the-home access, an area aligned with PMC-Sierra’s communications strategy.
Action taken
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)
1996
Exit from the personal-computer modem chipset marketStrategyBackground
Sierra Semiconductor was repositioning itself toward networking products and away from the increasingly competitive personal-computer modem chipset business.
Action taken
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.
Sources1 sources
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