Ambient Technologies

Cirrus Logic Inc.

Company type	Public
Industry	Semiconductor
Founded	1981 in Salt Lake City, Utah, U.S.
Founder	Suhas Patil
Headquarters	Austin, Texas , United States
Area served	Worldwide
Key people	John Forsyth (CEO)
Products	Analog, mixed-signal, and audio DSP integrated circuits
Website	www.cirrus.com

Cirrus Logic Inc. is a U.S.-based fabless semiconductor company that focuses on analog, mixed-signal, and audio DSP integrated circuits. Since 1998, its main office has been located in Austin, Texas.

The company's audio converters and processors are integrated into a variety of consumer electronics, including smartphones, tablets, laptops, digital headsets, automotive infotainment systems, home theater receivers, and smart home gadgets such as smart speakers. Cirrus Logic's client base exceeds 3,200 companies, featuring prominent names like Ford, Harman International, LG, Lenovo, Motorola, Panasonic, Samsung, Sony, Apple, and Vizio. Significantly, Apple represented 89% of Cirrus Logic’s revenue in 2025.

Established in 1981 by Suhas Patil under the name "Patil Systems, Inc." in Salt Lake City, the firm was rebranded as "Cirrus Logic" after moving to Silicon Valley in 1984.

The company currently holds upwards of 3,900 issued and pending patents.

History

In 1981, Suhas Patil founded Patil Systems, Inc. in Salt Lake City, Utah. Two years later, in 1983, Patil joined forces with Kamran Elahian and venture capitalist Fred Nazem to restructure the enterprise; Nazem and Company provided the initial capital. The following year, the company adopted the name Cirrus Logic and shifted its operations to Silicon Valley to capitalize on the expanding PC component market. Michael Hackworth took on the role of president and CEO from 1985 until 1999. Cirrus Logic went public in 1989 on Nasdaq under the ticker CRUS and broadened its product range by acquiring Crystal Semiconductor in 1991, entering the analog and mixed-signal converter IC sector.

During the early 1990s, Cirrus Logic produced PC graphics chips along with audio converters and magnetic storage devices. David D. French joined as president and COO in 1998 before ascending to CEO in 1999. French led a strategic pivot towards high-performance analog and digital processing chips tailored for consumer entertainment electronics through an acquisition-focused growth strategy. M. Yousuf Palla was appointed Vice President of Operations and Manufacturing to bolster operational capabilities. In April 2000, Cirrus Logic relocated its headquarters to Austin, Texas.

In June 2005, the company sold off its video products division to form Magnum Semiconductor. After French stepped down in March 2007, Jason Rhode assumed the roles of president and CEO in May of that year. Cirrus Logic expanded its market presence through key acquisitions such as Wolfson Microelectronics in 2014 for around $467 million and Lion Semiconductor in 2021 for $335 million, enhancing its product offerings and market penetration.

The company has also demonstrated commitment to community engagement by supporting initiatives like the Ann Richards School robotics program with an annual contribution of $10,000 over three years aimed at advancing STEM education and workforce development.

Ambient Technologies

In early 1999, Cirrus Logic divested its profitable PC Modem division by spinning it off as Ambient Technologies to concentrate on core business areas. The following year, Intel acquired Ambient Technologies and rebranded it as the "Modem Silicon Operation" division to broaden its modem technology assets.

Chronology of Major Milestones

• 1981 – Dr. Suhas Patil established Patil Systems Inc. in Salt Lake City, specializing in integrated circuit solutions for personal computer components.
• 1984 – The company rebranded as Cirrus Logic and relocated its headquarters to Silicon Valley.
• 1989 – Cirrus Logic launched its initial public offering on Nasdaq, trading under the symbol CRUS.
• 1991 – Acquired Crystal Semiconductor, broadening its portfolio in analog and mixed-signal integrated circuits.
• 1992 – Finalized the acquisition of Acumos Inc.
• 1994 – Formed the MiCRUS joint venture with IBM to develop ATM networking products.
• 1995 – Entered a $600 million joint manufacturing partnership with AT&T Microelectronics and signed a development contract with Advanced Telecommunications Modules Ltd.
• 1998 – Exited the PC graphics card market; David D. French was appointed president and COO, later becoming CEO; spun off the communications division.
• 1999 – Collaborated with Microsoft on the Maverick TM chip series; partnered with Rockwell International to develop ARM-based system-on-chip integrated circuits.
• 2000 – Corporate headquarters moved to Austin, Texas.
• 2001 – Initiated withdrawal from magnetic storage chip production; acquired startups specializing in video encoding/decoding, wireless networking, and networked digital audio technologies.
• 2003 – Terminated wireless networking operations.
• 2005 – Divested video product assets to establish Magnum Semiconductor, retaining a minority ownership stake.
• 2006 – Created the HD-AVR reference platform in cooperation with Genesis Microchip Inc.
• 2007 – Jason Rhode appointed as CEO; acquired Apex Microtechnology and audio semiconductor firm Tripath.
• 2012 – Sold hybrid product division to spin off Apex Microtechnology as an independent entity; consolidated Tucson operations into Austin headquarters; received DigiKey Distributor Partnership Award.
• 2014 – Expanded audio IC offerings by acquiring UK-based Wolfson Microelectronics.
• 2018 – Entered into an agreement with Apple to supply active noise cancellation chips for AirPods.
• 2019 – Became a strategic partner of Silicon Catalyst incubator supporting semiconductor startups.
• 2021 – Jason Rhode stepped down as CEO; John Forsyth took over as CEO; collaborated with Elliptic to enhance the CS35L45 smart amplifier through AI-driven Virtual Smart Sensor Platform technology.

Graphics Evolution

During the early 1990s, Cirrus Logic was a prominent provider of affordable graphics chips for personal computers. Its 2D GUI accelerators for Microsoft Windows stood out as some of the fastest options in the entry-level segment, outperforming VGA solutions from rivals such as Oak Technologies, Trident Microsystems, and Paradise (Western Digital). The 1992 release of the Cirrus GD5422 supported hardware acceleration for both 8-bit and 16-bit color depths and was among the most cost-effective SVGA controllers offering these capabilities.

By the mid-1990s, as personal computers adopted the Peripheral Component Interconnect (PCI) bus standard, Cirrus Logic fell behind competitors like S3 Graphics and Trident Microsystems. The delayed launch of the GD5470 "Mondello" chip negatively impacted its reputation in desktop graphics. Development efforts then shifted toward the faster GD5464 model utilizing Rambus memory technology, while the Mondello project was discontinued.

The last series of Cirrus Logic graphics processors—the GD546x "Laguna" PCI/AGP 3D accelerators—were distinguished by their use of Rambus RDRAM and early implementation of tiled memory architecture, a technique still prevalent in contemporary GPUs. Despite advanced features such as perspective-correct texture mapping and bilinear filtering, their performance was constrained by CPU speeds at that time, which limited triangle throughput. The GD546x series achieved nearly 2.5 million triangles per second at 25 pixels each, outperforming many competitors.

Following Intel's entry into the 3D graphics domain with the Intel i740 card, Cirrus Logic withdrew from this market segment valued at approximately $500 million annually. Although Intel's i740 initially underdelivered and failed to secure widespread adoption, its introduction shifted industry dynamics.

Cirrus Logic’s graphics cards continue to hold relevance in emulation environments; both QEMU and Bochs emulate Cirrus CLGD 5446 PCI VGA cards, while Bochs additionally supports CL-GD5430 ISA cards.

Desktop

• CL-GD410 + CL-GD420 – ISA SVGA chipsets deployed in the Video Seven VEGA VGA system (1987)
• CL-GD510 + CL-GD520 – ISA SVGA "Eagle II" series, notable for comprehensive CGA emulation capabilities (1988)
• CL-GD5320 – ISA SVGA chipset released in 1990
• CL-GD5401 and CL-GD5402 – ISA SVGA chipsets featured in Acumos VGA AVGA1/AVGA2 models
• CL-GD5410 – Early ISA SVGA chipset integrating RAMDAC and clock generation functions (1991)
• CL-GD5420 / CL-GD5421 – Advanced ISA SVGA chipsets with integrated 15/16-bit RAMDACs
• CL-GD5422 – Improved version of CL-GD5420 featuring a 32-bit memory interface, supporting up to 1280×1024 interlaced resolution
• CL-GD5424 – VLB adaptation of the CL-GD5422, closely related to the CL-GD5426
• CL-GD5425 – VGA controller capable of true color output with integrated TV output functionality
• CL-GD5426 / CL-GD5428 / CL-GD5429 – ISA/VLB chipsets incorporating BitBLT engines and enhanced memory clock speeds
• CL-GD5430 / CL-GD5434 / CL-GD5436 – PCI Alpine series featuring 32-bit host interfaces and internal memory interfaces up to 64 bits; memory expandable to 2 MB (1994)
• CL-GD5440 / CL-GD5446 – Alpine family variants with added motion video acceleration; the CL-GD5446 supports 64-bit VisualMedia acceleration
• CL-GD546X – Laguna Family VisualMedia Accelerators combining 2D/3D graphics, video acceleration, BitBLT engine, and hardware cursor support; utilizes single-channel RDRAM delivering high bandwidth
  • CL-GD5462 – Lacks 3D acceleration capabilities
  • CL-GD5464 – Incorporates hardware-based 3D acceleration (PCI interface)
  • CL-GD5465 – Supports AGP interface
• CL-GD5480 – Enhanced Alpine accelerator featuring 100 MHz SGRAM and MPEG-2 video acceleration

This lineup exemplifies Cirrus Logic's strategic emphasis on delivering cost-efficient, integrated graphics solutions that effectively balanced performance with affordability throughout its significant expansion within the PC graphics sector.

Mobile

• CL-GD610 + 620 (1989) – Early VGA-compatible graphics chipsets designed for mobile applications
• CL-GD6420/6440 – Integrated into select notebook models, these derive from earlier Cirrus designs such as the 5410 and AVGA2 series
• CL-GD6205/6215/6225/6235 – Mobile-oriented chipsets compatible with the CL-GD5420 architecture
• CL-GD7541/7542/7543/7548 – Successor series aligned with the CL-GD5428 family, enhancing laptop display functionality

See also

• Graphics card
• Graphics processing unit

External links

• – Former PC modem integrated circuit division spun off and subsequently acquired by Intel