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Key Information
SiRF Technology, Inc. was an American pioneer in the commercial use of GPS technology for consumer applications. The company was founded in 1995 and was headquartered in San Jose, California. Notable and founding members included Sanjai Kohli,[2] Dado Banatao, and Kanwar Chadha.[citation needed] The company was acquired by British firm CSR plc in 2009, who were in turn subsequently acquired by American company Qualcomm on 13 August 2015.[3][4]
SiRF manufactured a range of patented GPS chipsets and software for consumer navigation devices and systems. The chips are based on ARM controllers integrated with low-noise radio receivers to decode GPS signals at very low signal levels (typically -160dBm). SiRF chips also support SBAS to allow for differentially corrected positions.
SiRFstarIII
[edit]SiRFstarIII architecture is designed to be useful in wireless and handheld location-based services (LBS) applications, for 2G, 2.5G, 3G asynchronous networks. The SiRFstarIII family comprises the GRF3w RF IC, the GSP3f digital section, and the GSW3 software that is API compatible with GSW2 and SiRFLoc. The chips have been adopted by major GPS manufacturers, including Sony, Micro Technologies, Garmin, TomTom and Magellan.
SiRFatlas IV
[edit]SiRFatlas IV is a multifunction location system processor and is meant for entry-level Personal Navigation Devices (PNDs). The SiRFatlas IV is a cheaper version of the very popular, but rather expensive SiRFPrima platform.[5][6] Has GPS/Galileo baseband, LCD touch-screen controller, video input, 10-bit ADC and a high-speed USB 2.0.
SiRFstarV
[edit]SiRFstarV chips, launched in 2012, are capable of tracking NAVSTAR, GLONASS, Galileo, Compass, SBAS, and future GNSS signals. The SiRFusion platform integrates positioning from GNSS, terrestrial radio solutions such as Wi-Fi and cellular, and MEMS sensors including accelerometers, gyroscopes, and compasses. SiRFusion can then combine this real-time information with cellular base station and Wi-Fi access point location data, ephemeribased aiding information from the CSR Positioning Center (CPC) to generate accurate and reliable position updates.
Acquisition
[edit]On 10 February 2009, UK wireless chip company CSR announced it was buying SiRF in a share deal worth $136 million.[7]
References
[edit]- ^ "SiRF Technology Holdings Inc. Announces Financial Results for Fourth Quarter and Fiscal 2007". SiRF. Retrieved 2008-07-10.[permanent dead link]
- ^ Sujit John (Apr 5, 2010). "Father of mass market GPS is an Indian - Times of India". The Times of India. Retrieved 2021-12-31.
- ^ says, Bigzuo (October 20, 2014). "Qualcomm to Acquire SiRF Chipmaker CSR". GPS World.
- ^ "About". Qualcomm. March 24, 2014.
- ^ Faucheux, Misty (June 16, 2009). "What is SiRFatlas IV? The Latest Chipset from SiRF & What Drives Your Personal Navigation Devices?".
- ^ "SiRFatlasIV unveiled: Low cost GPS and multifunction processor". Archived from the original on 2016-01-16.
- ^ "CSR purchase announcement". CSR. Retrieved 2009-04-17. [dead link]
External links
[edit]from Grokipedia
SiRF Technology, Inc. was an American fabless semiconductor company specializing in GPS receiver chips and associated software that enabled location-based services in consumer electronics.[1] Founded in February 1995 in San Jose, California, the company focused on bringing Global Positioning System (GPS) technology to mainstream consumer markets, including mobile devices, portable navigation systems, and wireless products.[2][3]
SiRF Technology pioneered advancements in low-power, high-sensitivity GPS solutions, most notably through its SiRFstar series of chipsets, which integrated ARM-based processors with proprietary signal processing to improve accuracy and acquisition times in challenging environments.[4] These products powered early location-aware applications in automotive navigation, fitness trackers, and smartphones, contributing to the widespread adoption of GPS in personal devices during the 2000s.[5] The company's innovations, such as the SiRFstarIII chipset, emphasized energy efficiency and multifunctionality, including Bluetooth integration, to support emerging mobile computing platforms.[6]
SiRF went public on the NASDAQ in 2004, achieving profitability amid rapid growth in the consumer GPS market.[7] In 2009, it was acquired by British wireless chipmaker CSR plc in a $136 million all-stock transaction, forming a combined entity focused on connectivity and location technologies.[8] CSR itself was later acquired by Qualcomm in 2015, integrating SiRF's legacy GPS expertise into broader semiconductor portfolios.[9]
History
Founding and Early Development
SiRF Technology was founded in February 1995 in San Jose, California, by Kanwar Chadha, with the ambitious vision of making Global Positioning System (GPS) technology accessible to mainstream consumers at a time when the market was dominated by professional and military applications.[2][10] Operating as a fabless semiconductor company, SiRF focused on developing integrated circuits and intellectual property for GPS receivers, emphasizing low power consumption and high sensitivity to enable integration into portable devices.[2] In its early years, SiRF concentrated on pioneering GPS architectures tailored for consumer electronics, culminating in the release of its first chipset, SiRFstar I, in 1996.[11] This three-chip solution, fabricated in 350 nm CMOS technology, achieved a sensitivity of -142 dBm and power consumption under 1 W, marking a significant step toward compact, battery-efficient GPS receivers suitable for non-professional use.[3] Building on this foundation, SiRF introduced the SiRFstar II chipset in 1998, which was the first to incorporate support for Wide Area Augmentation System (WAAS) and European Geostationary Navigation Overlay Service (EGNOS) corrections in consumer-grade products, enhancing accuracy and reliability for everyday applications like personal navigation.[3] The SiRFstar II architecture, announced publicly in 1999, represented a breakthrough in GPS design by offering a highly integrated, platform-optimized solution available both as a chipset and an IP core, allowing broader adoption in devices ranging from handheld units to embedded systems. This innovation helped SiRF achieve rapid market penetration, becoming the first company to ship over 1 million GPS chipsets in a single month by the early 2000s, and laid the groundwork for the company's emphasis on sensitivity and signal processing advances that would define its later products.[3][4]Expansion and Public Offering
Following its founding in 1995, SiRF Technology experienced significant expansion in the early 2000s, driven by the burgeoning market for GPS-enabled devices in mobile phones, automotive navigation, and personal electronics. The company's revenue grew rapidly from $15 million in 2001 to $30.4 million in 2002 and $73.1 million in 2003, reflecting increased adoption of its SiRFstar chipsets, which offered superior sensitivity for urban and indoor positioning. This growth was fueled by strategic partnerships with major manufacturers such as Motorola, Hewlett-Packard, Toyota, and Honda, as well as a shift toward licensing its intellectual property to reduce costs and broaden market reach—for instance, Motorola transitioned from purchasing chips to licensing SiRF's technology. By 2003, SiRF achieved profitability for the first time, supported by cost reductions that brought GPS module prices down from $200–$300 to $40–$50, enabling wider integration into consumer products.[5][12] The company's expansion also involved building a robust investor base, including Dell, Nokia, Intel, Matsushita, and MiC (an NTT DoCoMo affiliate), which provided funding through multiple venture rounds totaling over $200 million by 2004. SiRF had attempted an initial public offering in 2000 but canceled it amid market conditions; renewed momentum in the GPS sector, including E911 compliance requirements, positioned it for a successful relaunch. This period marked SiRF's transition from a startup focused on semiconductor design to a key player in location technology, with operations expanding to include sales offices and design centers globally.[13][5] SiRF Technology went public on April 22, 2004, listing on the NASDAQ under the ticker SIRF. The initial public offering raised $132 million through the sale of approximately 10 million shares at a price range initially set at $10–$12 per share. Underwritten by firms including Thomas Weisel Partners and Lehman Brothers, the IPO valued the company at around $500 million post-offering and provided capital for further research, development, and global expansion. The offering capitalized on the GPS market's projected growth, with SiRF's market share in GPS chipsets exceeding 50% by volume in 2003.[12][13][14]Strategic Acquisitions
SiRF Technology Holdings, Inc. pursued several strategic acquisitions in the mid-2000s to expand its expertise beyond core GPS receiver technology into complementary areas such as radio frequency (RF) design, broadband wireless, Bluetooth integration, and advanced navigation processing. These moves aimed to enhance SiRF's position in the growing market for multifunction location-aware devices, particularly in mobile handsets and consumer electronics. By acquiring specialized firms, SiRF integrated proprietary technologies and talent to accelerate product development and broaden its silicon and software offerings.[11] In February 2003, SiRF acquired Enuvis, Inc., a developer of assisted GPS (A-GPS) and wireless location technologies, for an undisclosed amount. This acquisition bolstered SiRF's capabilities in urban and indoor positioning for mobile devices, integrating Enuvis' innovative signal processing IP into the SiRFLoc multimode platform.[15] In April 2005, SiRF acquired Kisel Microelectronics AB, a Stockholm-based developer of radio and mixed-signal integrated circuits, for approximately $33 million in cash and stock. This acquisition provided SiRF with Kisel's expertise in complex RF transceiver designs, enabling the company to develop integrated GPS solutions with enhanced wireless connectivity features, such as Bluetooth radios. The deal added about 30 engineers to SiRF's team and supported the creation of single-chip GPS/Bluetooth architectures, aligning with the industry's shift toward compact, multifunctional semiconductors. However, in 2008, SiRF spun off its Swedish operations back to an independent Kisel Microelectronics, retaining a 15% stake while continuing to leverage the firm's services for RF support.[16][17] In June 2005, SiRF acquired Motorola's GPS chipset product lines for $20 million in cash. This deal strengthened SiRF's core GPS offerings, incorporated Motorola's established designs and patents, and solidified its role as a preferred GPS supplier to Motorola for integration into mobile phones and other devices.[18] Early 2006 saw two key acquisitions that bolstered SiRF's wireless capabilities. In January 2006, SiRF acquired Impulsesoft Pvt. Ltd., a Bangalore-based specialist in Bluetooth stereo solutions and embedded software, for $15 million in cash. This move strengthened SiRF's software stack for Bluetooth integration, adding 55 experienced developers and expanding its India operations to support value-added features like audio streaming in GPS-enabled devices. In March, SiRF purchased TrueSpan, Inc., a developer of silicon and software platforms for orthogonal frequency-division multiplexing (OFDM) technologies used in WiMAX and other broadband wireless standards. Valued at an undisclosed amount, the deal integrated TrueSpan's approximately 30 employees, primarily in Bangalore, India, into SiRF, enhancing its portfolio with location-aware broadband solutions for emerging mobile data applications.[19][20][21] SiRF's most significant acquisition occurred in June 2007, when it agreed to buy Centrality Communications, Inc., a Redwood City, California-based provider of navigation processor solutions for mobile devices, for about $283 million in stock and cash—or approximately 8.1 million SiRF shares. The deal, completed in August 2007, combined Centrality's system-on-chip (SoC) processors for navigation and infotainment with SiRF's GPS expertise, creating a robust multifunction location platform capable of handling multimedia and mapping applications. This strategic integration targeted the burgeoning demand for automotive and portable navigation systems, positioning SiRF as a leader in converged location technologies. The acquisition was pivotal in diversifying SiRF's revenue streams amid intensifying competition in the GPS chipset market.[22][23][24]Technology and Innovations
Core GPS Receiver Architecture
The core GPS receiver architecture developed by SiRF Technology centers on highly integrated single-chip solutions that combine radio frequency (RF) front-end processing with digital baseband signal processing, enabling high sensitivity and low power consumption for consumer-grade applications.[25] This design typically features a low-noise amplifier (LNA), mixer, automatic gain control (AGC), and analog-to-digital converter (ADC) in the RF section to capture and digitize weak GPS L1 C/A-code signals at 1575.42 MHz.[26] The digitized signals are then processed by a custom GPS digital signal processor (DSP) that performs correlation, acquisition, and tracking, often supported by an ARM7TDMI microprocessor for navigation computations and system control.[27] In SiRF's architecture, the baseband processing emphasizes parallel correlator engines to handle multiple satellites simultaneously. For instance, the Satellite Signal Tracking Engine (SSTE) in earlier designs like SiRFstar II utilizes up to 1920 time-frequency search channels and 12 parallel tracking channels operating at 48 MHz, with programmable digital loops for carrier and code synchronization to mitigate multipath errors below 50 ns.[26] Subsequent generations, such as SiRFstar III, advance this with over 200,000 effective correlators leveraging fast Fourier transform (FFT) and matched filtering techniques, allowing autonomous acquisition and tracking of up to 20 satellites even at signal levels as low as -159 dBm.[27][25] Integrated memory, typically 1 Mb of SRAM shared between the DSP and CPU, stores ephemeris data and supports battery-backed operation for rapid hot starts under 1 second.[27] Power management is a hallmark of SiRF's core design, incorporating modes like TricklePower that reduce consumption to under 25 mA during intermittent tracking while maintaining accuracy better than 5 meters with differential GPS (DGPS) augmentation.[26] The architecture's modularity allows for software-configurable features, including support for Satellite-Based Augmentation Systems (SBAS) like WAAS, with the DSP handling real-time navigation updates at low interrupt rates (around 100 ms) to minimize CPU load.[25] This integrated approach, housed in compact packages like 7 mm × 10 mm BGA, facilitates deployment in handheld and wireless devices by requiring few external components.[27]Sensitivity and Signal Processing Advances
SiRF Technology advanced GPS receiver sensitivity by developing techniques that enabled reliable signal acquisition and tracking in environments with severe signal attenuation, such as urban canyons, dense foliage, and indoor settings. Conventional GPS receivers typically lose lock below a carrier-to-noise density (C/N₀) of about 31 dB-Hz (equivalent to approximately -173 dBW received power assuming a -204 dBW/Hz noise floor), but SiRF's high-sensitivity designs achieved tracking thresholds down to 18 dB-Hz (equivalent to -186 dBW) through extended signal dwell times exceeding the standard 20 ms coherent integration limit. This was realized via a combination of long coherent integration (up to 340-800 ms) and subsequent non-coherent accumulation, which amplified weak signals while mitigating phase noise accumulation. These methods required initial open-sky acquisition for ephemeris and time synchronization but provided autonomous operation thereafter, yielding about 13 dB greater sensitivity than standard receivers.[28] Central to these advances was SiRF's proprietary digital signal processing (DSP) architecture, exemplified by the GSP1/LX chip in early SiRFstar receivers, which employed parallel correlators to simultaneously process signals from multiple satellites (up to 12 channels). This parallel structure facilitated rapid code-phase detection using matched filtering and Doppler compensation, reducing acquisition times in low-signal conditions and enabling continuous tracking with minimal power overhead. The SnapLock feature further enhanced performance by preserving satellite ephemeris, almanac data, and position estimates in non-volatile memory during brief power cycles (up to 5 minutes), allowing sub-second time-to-first-fix (TTFF) restarts without full reacquisition. Such innovations prioritized standalone weak-signal operation over network-assisted methods, distinguishing SiRF from competitors reliant on external aiding.[29] Performance evaluations confirmed the efficacy of these techniques, with SiRF receivers demonstrating higher measurement availability—averaging 8.1 visible satellites in forested environments compared to 6.4 for conventional units—and fewer tracking losses under 33 dB attenuation. However, the heightened sensitivity increased vulnerability to multipath errors, resulting in position errors up to 54 m in echo-dominated scenarios, though typical root-mean-square errors remained below 25 m in urban tests. These trade-offs underscored SiRF's focus on availability over precision in degraded signals, influencing subsequent GNSS chipset designs.[28][30]Integration with Other Wireless Technologies
SiRF's GPS receiver technology was designed for seamless integration with Bluetooth, enabling wireless data transmission between GPS modules and host devices such as PDAs and mobile phones. In 2006, SiRF introduced the SiRFLink1 single-chip solution, which combined its SiRFstar GPS core with Bluetooth 1.2 functionality, reducing component count, size, power consumption, and cost compared to discrete implementations.[31] This integration leveraged SiRF's acquisitions of Kisel Microelectronics for RF design and Impulsesoft for Bluetooth software, facilitating applications in automotive navigation and portable devices where cable-free connectivity was essential.[31] For cellular networks, SiRF pioneered assisted GPS (A-GPS) through its SiRFLoc architecture, introduced in 1999 to meet FCC E911 requirements for emergency location services. SiRFLoc enhanced satellite acquisition, time synchronization, and weak-signal tracking by utilizing cellular network data, operating in standalone, handset-centric, or network-centric modes with minimal additional hardware.[32] This allowed easy embedding into existing cellular handsets, improving time-to-first-fix and indoor performance while maintaining low power and cost; field tests demonstrated compliance with 125-meter accuracy mandates.[32] Partnerships, such as with SignalSoft in 2000 for the Location Manager platform and NXP in 2007 for Nexperia 3G reference designs, further optimized A-GPS deployment in wireless carriers like Sprint-Nextel.[33][34][35] In later developments, SiRF's receivers addressed coexistence with Wi-Fi and 3G radios via advanced interference mitigation. The SiRFstar IV chipset, released by CSR around 2010, incorporated active jammer removal to detect and suppress up to eight interference sources, including Wi-Fi and cellular signals, ensuring reliable GPS operation in multi-radio environments like smartphones.[36] This technology enabled high-sensitivity navigation down to -163 dBm tracking levels without compromising other wireless functions, as seen in integrations with Samsung Galaxy devices.[36]Products
SiRFstar III
The SiRFstar III, part of the GSC3 family, is a single-chip GPS receiver chipset developed by SiRF Technology, integrating RF front-end and baseband processing on a 0.13 μm CMOS process in a compact 7 mm × 10 mm × 1.4 mm BGA package. It features an ARM7TDMI processor core, 1 Mb SRAM, and optional 4 Mb internal flash (in the GSC3f variant), enabling standalone operation with built-in peripherals including two UARTs, a high-speed serial bus, and up to 14 GPIOs. This architecture supports modular software (GSW3) compatible with real-time operating systems, facilitating integration into mobile devices, navigation systems, and wireless handsets.[27][25] A key innovation in the SiRFstar III is its advanced signal processing, employing over 200,000 effective correlators through a combination of fast Fourier transform (FFT) techniques and matched filtering, which enhances weak-signal acquisition and tracking. The chipset achieves acquisition sensitivity down to -159 dBm and tracking sensitivity to -155 dBm, allowing reliable fixes in challenging environments such as urban canyons and indoors—conditions where traditional GPS receivers often fail. It supports 20 all-in-view channels for simultaneous processing of GPS L1 C/A-code signals and Satellite-Based Augmentation Systems (SBAS) like WAAS and EGNOS, with multi-mode Assisted GPS (A-GPS) via SiRFLoc for faster time-to-first-fix (TTFF) using cellular network aiding. Additional technologies include the patented EARC (extended acquisition range correlator) for precise frequency transfer and TricklePower modes for ultra-low standby power (as low as 50 μA).[27][25][37] Performance-wise, the SiRFstar III delivers hot-start TTFF under 1 second with A-GPS aiding and cold-start TTFF of 15 seconds in open sky or 35 seconds indoors, with position accuracy better than 10 meters autonomously and under 5 meters with SBAS corrections. Power consumption is optimized at 75 mW during 1 Hz tracking updates, dropping to 700 μA in standby, making it suitable for battery-constrained applications. These capabilities positioned the SiRFstar III as a benchmark for high-sensitivity GPS in the mid-2000s, powering devices from portable navigators to integrated mobile platforms like Intel's Ultra Mobile PCs.[25][37]SiRFstar IV
The SiRFstar IV is a high-performance GPS receiver architecture developed by SiRF Technology and launched in July 2009, shortly before the company's merger with CSR plc.[38] It introduced the SiRFaware technology platform, which enables always-on location awareness with significantly reduced power consumption compared to prior generations, allowing devices to maintain satellite ephemeris data opportunistically without full-power operation. This architecture addressed key limitations in mobile GPS, such as battery drain and slow fixes in challenging environments, by incorporating advanced signal processing and power management techniques.[39] Central to SiRFstar IV is its low-power RF CMOS single-die design, which integrates baseband processing, an ARM7 CPU, RF functions, and navigation software into a compact package measuring 3.5 × 3.2 × 0.6 mm for the GSD4e variant.[40] The chipset supports 48 all-in-view tracking channels and operates on the L1 frequency at 1,575.42 MHz, with compatibility for WAAS augmentation to enhance accuracy.[40] It achieves exceptional sensitivity, with acquisition down to -160 dBm and tracking to -163 dBm, enabling reliable performance in urban canyons and under interference.[41] An active jammer remover handles up to 8 continuous-wave jammers at up to 80 dB-Hz, mitigating disruptions from nearby wireless devices.[40] Power efficiency is a hallmark of SiRFstar IV, featuring TricklePower mode that consumes only 8 mW at 1 Hz—2.5 times lower than industry benchmarks at the time—while retaining hot-start conditions with 20 times less power than competitors.[39] Time-to-first-fix (TTFF) metrics include hot starts under 1 second, warm starts under 30 seconds, and cold starts under 35 seconds, supporting rapid location acquisition even at low signal levels. The architecture's adaptive micropower controller dynamically adjusts receiver sectors to minimize energy use, making it suitable for battery-constrained applications without sacrificing fix speed or accuracy.[42] SiRFstar IV was released in two primary variants: the GSD4t, a host-based receiver optimized for smartphones and mobile internet devices with SiRFaware for seamless integration into application processors; and the GSD4e, a standalone engine with built-in CPU for geo-tagging in cameras, camcorders, and wearables.[42] It powered early implementations like the Samsung Galaxy S II smartphone, where it delivered superior urban navigation and low-power tracking.[41] Following CSR's acquisition by Qualcomm in 2015, the technology continued in automotive and embedded modules, emphasizing its legacy in enabling compact, efficient GNSS solutions.[40]| Specification | Details |
|---|---|
| Channels | 48 all-in-view tracking[40] |
| Sensitivity | Acquisition: -160 dBm; Tracking: -163 dBm[41] |
| TTFF | Hot: <1 s; Warm: <30 s; Cold: <35 s |
| Power Consumption | TricklePower: 8 mW @ 1 Hz; Hot-start retention: 20x less than competitors[39] |
| Jammer Removal | Up to 8 CW jammers @ 80 dB-Hz[40] |
| Interfaces | UART, SPI, I²C[40] |