Search Results

< Back AEA Linear Systems Mar 17, 2023 AEA’s Ribbon Microphones & Linears’ JFETs AEA When John Kurlander sought to capture the vast array of sound for the Lord of the Rings movies, he turned to Wes Dooley and his ribbon microphones. And for years, when Wes needed ultra-low-noise semiconductors to build and amplify those microphones, he turned to Linear Systems, Inc. “Linear Systems has kept that tradition going of making parts that are competitive with the [discontinued Toshiba] SK170s and 389s,” Dooley said in a recent interview. “And that gives us the ability to make compact, high-performance audio products.” “We make the quietest ribbon mic in the world, the A440, and the higher SPL A840. Both of them use the [Linear Systems] LSK389, for the output drivers and their current supply,” Dooley said. Dooley's company, Audio Engineering Associates (AEA), also uses the LSK389 in front ends of its RPQ and RPQ 500 preamplifiers, which were designed for use with ribbon microphones. AEA's microphone business started with ribbon mics for classical music used as movie scores. “John Kurlander did all three Lord of the Rings using AEA mics on strings left and right almost as strong in the mix as the main orchestra mics,” Dooley said. “When you work with such people, one really learns to be of service.” AEA's customer list reads like a Who's Who of Grammy and Academy Award-winning recording engineers and artists. Among the many examples, sound engineer Michael Bishop, winner of eight Grammy awards, extensively uses AEA's A840 microphones and AEA preamps for his recordings. Shawn Murphy, who's worked on over 330 films and won an Academy award for Jurassic Park, also relies on AEA's preamps and microphones. One of the best parts of AEA's website is the long list of reviews and mentions by users . Dooley, a lifelong ribbon microphone enthusiast and developer, got into the business by repairing ribbon mics built by RCA during the golden age of radio. “We started servicing mics in '76 when RCA shut down making them,” he said. “Many of our favorite RCA designs were from the mid '30s, when a designer's foremost tool was listening to live music. Critical listening was the gold standard as acoustical measurements were cumbersome.” “We've adopted that approach, which is: musicality trumps metrics. The mic has to sound good to people in the music business,” Dooley said. “If it doesn't sound good, measurements don't matter. Once you have a mic that sounds good to people who have experienced ears, then measurements are very important, as they are the key to consistent production.” “So we first strive to make sure it sounds musical, and then we measure what it does,” Dooley said. “Because, as one of my mentors, Richard Heyser, said, if it measures well but doesn't sound right, then you're measuring the wrong things. Often you find you don't know what the right thing to measure is. Over time you discover what those metrics might be. Ultimately, it's a matter of how it sounds. Since we come from an acoustic music tradition, it's pretty simple: you put the mic in front of live music, and compare that live sound with the reproduction, to see how close it is.” Dooley told the story of working with legendary bluegrass fiddle player/violinist Richard Greene. Greene, along with his wife, a violinist with the LA Chamber Orchestra, recorded samples using over 20 microphones. “The next day, when they had 'fresh ears,' they listened to all the recordings and said the one made using our ribbon microphones was the best,” Dooley said. “And that's what we try for, for the musicians to experience that this is the closest they've ever heard to an actual performance.” Asked to comment for this article, Greene had high praise for Dooley and his microphones. “Silky, smooth, best violin sound I ever heard, Wes is amazing and his tech support and other free maintenance are over the top,” Greene wrote. “I will never have any use for any other mic on my violin. I have the AEA 440.” Dooley said this close interaction with artists drives how he builds microphones and preamps. “The whole thing,” he said, “is to build tools they need. That is the key to survival for a small business doing high-performance products.” The LSK389 “is a very good part for manufacturing,” Dooley said. AEA uses the “C” grade of the LSK389. “We started with the 'A' [grade], but then we realized it didn't make any difference for what we were doing,” he said. The LSK389 is graded by IDSS ; all three grades have the same ultra-low-noise characteristics. The Linear Systems LSK389 part used by AEA is an ultra-low-noise junction field effect transistor. Linear System Founder and CEO John H. Hall began working on a JFET similar to Toshiba's 2SK389 about the time that the Japanese company began to discontinue the device 10 years ago. “Toshiba kept its production process for the 389 secret, so we had to figure out on our own how to build something to the same specification, which was extremely difficult,” Hall said. Expertise brought to Linear Systems is based on processes and products Hall developed since 1962 at Amelco, Union Carbide, Intersil, and Micro Power Systems. Hall, a protégé of Silicon Valley legend Dr. Jean Hoerni, was the director of IC Development at Union Carbide, co-founder and vice president of R&D at Intersil, and founder/president of Micro Power Systems. Much of Linear Systems' current development work focuses on lower-noise JFETs. The production techniques Hall conceived to squeeze the last bit of noise out of the 389 led to development of another part, the LSK489. The LSK489 has less transconductance than the 389, and though this increases noise slightly, it makes the part easier to design into new circuits. “While the 389 is the perfect part for some users, such as Wes Dooley, who need the lowest noise levels in existence, we found that the high gate-to-drain capacitance of the 389 caused problems for some of our other customers,” Hall said. “Building a high transconductance part, such as the 389, formed part of the basis for providing ultra-low-noise levels, but the high input capacitance causes intermodulation distortion in some higher-frequency applications,” Hall said. “Since we had created some advanced processing techniques to make the 389, we decided to go back and look at creating a part with lower capacitance using the same processes.” Though Dooley's ribbon microphone and other devices take advantage of the 389's low noise level, other developers could tolerate a slightly higher noise level in a part that has much lower input capacitance due to a lower transconductance, Hall said. The lower capacitance and other features make the LSK489 a lower-noise, functional replacement for Linear Systems' LS840-series of JFETs, as well as the Siliconix U401-403 series. Dooley's precision ribbon microphones are perfect applications of the LSK389, Hall said. “Both ribbon microphones and JFETs are very difficult to design and build, but there's really no other way to achieve the level of performance needed than to do the work this way.” The circuit design work using the LSK389s was done for AEA by Fred Forssell of http://www.forsselltech.com . For more on Dooley's microphones, go to: http://www.ribbonmics.com Data sheets for the LSK389 and LSK489, the application notes for the LSK489, and a good paper on general JFET theory and use can be downloaded at: http://linearsystems.com .

< Back Headphone Amp Eval Board Introduction Linear Integrated Systems headphone amplifier evaluation board includes the following features: Stereo, single‐ended input and single‐ended output 400 mW output power into 100Ω Wide frequency response (10Hz‐200kHz; ‐1dB) Voltage gain 5 (14dB) Low distortion (THD+N is less than 1% at 10Hz‐20kHz at 5Vrms into 100Ω and less than 0.1% from 10 Hz to 20 kHz at 1Vrms into 100Ω load) Short‐circuit protection Pop reduction (slow start) circuit Defeatable cross‐feed circuit Volume control Overvoltage and reverse polarity power protection Audio input and output connections: left and right RCA phono jack inputs, ¼” stereo phone jack output External 9V–16V supply input External power supply connector: power jack, inside diameter 2.1mm, outside diameter 5.5mm Read More

The Linear Systems family of high speed DMOS switches is designed to handle a wide range of video, fast ATE, telecom and other analog switching applications. DMOS High Speed Switches The Linear Systems family of DMOS devices is designed to handle a wide range of video, fast ATE, telecom and other analog switching applications. These components are capable of ultrafast switching speeds (tr = 1 ns, tOFF = 3 ns) and excellent transient response. Thanks to reduced parasitic capacitances, our DMOS can handle wideband signals with high off-isolation and minimum crosstalk. SD/SST210 Series SD/SST210 SINGLE, HIGH SPEED N-CHANNEL LATERAL DMOS FET SWITCH Read More SD/SST211 Series SD211DE SINGLE, HIGH-SPEED N-CHANNEL LATERAL DMOS FET SWITCH Read More SD5000 Series SD5000 SERIES QUAD, HIGH SPEED N-CHANNEL, LATERAL DMOS FET SWITCH Read More

< Back Interfacing Sensors & Transducers Introduction Abstract: A discussion of methods of amplifying and signal-conditioning for sensors with low level outputs in the presence of high ambient electrical noise sources. Advantages and disadvantages of some common amplifier circuits are considered. Read More

< Back Military Sensors White Paper Linear Systems Mar 17, 2023 Linear Systems' White Paper Describes Lowest Noise Amplification for Sensor Signal Chains FREMONT, Calif., May 27, 2021 /PRNewswire/ -- Linear Systems, a world class producer of ultra low noise JFETS and semiconductors, has released an application note on creating low-noise signal chains for military sensors. The paper, "Military Higher-Performance Sensor Signal Chains," offers engineers solutions using ultra-low-noise discrete components added to an IC-based circuit to produce the better-performing signal chains in sensitive applications. Included are key applications with reference designs such as: Piezoelectric Element Preamps; Hydrophones; Accelerometers; Photodiode Preamps; and other types of sensors where discrete components are uniquely capable of performing critical initial amplification of sensor signals. "Better sensor systems enable earlier threat detection and more effective countermeasures, " Mr. Tim McCune said. "Our ultra-low-noise JFETS enable designers to build more sensitivity and capability into their sensor systems. This improved capability translates directly into greater value to the end users of these sensors." Linear Systems is a designer, manufacturer and seller of precision, high-performance, small-signal discrete semiconductors. A Silicon Valley company founded in 1987, it produces ultra-low-noise, monolithic dual and single JFETs and bipolar transistors, along with high-speed DMOS switches, small-signal MOSFETs, ultra-low leakage diodes and BiFET amplifiers. These parts have been designed into world-class products in the areas of: Test & Measurement, Audio, Scientific Optical, Military Sensor; Industrial Controls; and Hybrids. The White Paper can be downloaded at: High-Performance Military Sensor Signal Chains Data sheets, applications notes, SPICE models and other information can be downloaded at www.linearsystems.com . For More Information: Call Linear Systems toll free phone number: (800) 359-4023, regular business line: (510) 490-9160 or fax: (510) 353-0261. Email: sales@linearsystems.com Website: www.linearsystems.com SOURCE Linear Integrated Systems

LOG CONFORMANCE, MONOLITHIC DUAL, NPN TRANSISTOR < Back LS318 LOG CONFORMANCE, MONOLITHIC DUAL, NPN TRANSISTOR The LS318 Log Conformance, Monolithic Dual, NPN Transistor is a direct replacement for the Micro Power Systems MP318 Series. It is ideal for Log Conformance, Transistors Amplifier & Switching Applications. It is available the in TO-71 6L RoHS, TO-78 6L RoHS, PDIP 8L ROHS and SOIC 8L RoHS package, as well as bare die. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: LS318 TO-71 6L RoHS LS318 TO-78 6L RoHS LS318 PDIP 8L RoHS LS318 SOIC 8L RoHS LS318 Die Datasheet Spice Model Application Notes

SINGLE, HIGH FREQUENCY, N-CHANNEL JFET AMPLIFIER < Back J/SST/U308 Series SINGLE, HIGH FREQUENCY, N-CHANNEL JFET AMPLIFIER The J/SST/U308 Series Single, High Frequency, N-Channel JFET Amplifier is a direct replacement for the Fairchild, NXP and Siliconix-Vishay equivalent part. It is ideal for High Frequency Applications. The series is available in the TO-92 3L RoHS, TO-18 3L RoHS and SOT-23 3L RoHS package, as well as in die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information: Below are the options you have when ordering this part series: J308 TO-92 3L RoHS J309 TO-92 3L RoHS J310 TO-92 3L RoHS U308 TO-18 3L RoHS U309 TO-18 3L RoHS U310 TO-18 3L RoHS SST308 SOT-23 3L RoHS SST309 SOT-23 3L RoHS SST310 SOT-23 3L RoHS U308 Die U309 Die U310 Die Datasheet Spice Model Application Notes

SINGLE P-CHANNEL JFET SWITCH < Back LSJ/SST94 SINGLE P-CHANNEL JFET SWITCH The LSJ/SST94 Single, Ultra-Low noise, P-Channel JFET Amplifier is a direct replacement for the Toshiba 2SJ94. It is ideal for Ultra-Low Noise Audio/Acoustic Applications. Available in the TO-92 3L RoHS, SOT-89 3L RoHS, as well as in die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information: Below are the options you have when ordering this part series: LSJ94 TO-92 3L RoHS SST94 SOT-23 3L RoHS LSJ94 Die Datasheet Spice Model Application Notes

MONOLITHIC DUAL, NPN TRANSISTOR < Back IT124 MONOLITHIC DUAL, NPN TRANSISTOR Previous Next

SINGLE, LOW LEAKAGE PICO-AMP DIODES < Back J/SST/PAD Series SINGLE, LOW LEAKAGE PICO-AMP DIODES The PAD Series Ultra-Low Leakage, Protection Diode is a direct replacement for the Siliconix-Vishay part series. It is ideal for Pico Amp, Ultra-Low Leakage, Protection Diode Applications. This part series is available in the TO-72 3L RoHS, TO-92 2L RoHS and SOT-23 3L RoHS package, as well as die form. Advanced screening options are available for our diverse product lineup, featuring JFETS, Bipolar transistors, MOSFETs, current regulators, and Diodes. Our special screening covers all the parameters listed in the standard datasheet, including comprehensive package pin-out. Connect with our experienced technical team to discuss your specific needs and tailor your requirements—email us at support@linearsystems.com or call (510) 490-9160. MOQ applies to these specialized services. Ordering Information Below are the options you have when ordering this part series: PAD1 TO-72 3L RoHS PAD2 TO-72 3L RoHS PAD5 TO-72 3L RoHS PAD10 TO-72 3L RoHS PAD20 TO-72 3L RoHS PAD50 TO-72 3L RoHS PAD100 TO-72 3L RoHS JPAD1 TO-92 2L RoHS JPAD2 TO-92 2L RoHS JPAD5 TO-92 2L RoHS JPAD10 TO-92 2L RoHS JPAD20 TO-92 2L RoHS JPAD50 TO-92 2L RoHS JPAD100 TO-92 2L RoHS SSTPAD1 SOT-23 3L RoHS SSTPAD2 SOT-23 3L RoHS SSTPAD5 SOT-23 3L RoHS SSTPAD10 SOT-23 3L RoHS SSTPAD20 SOT-23 3L RoHS SSTPAD50 SOT-23 3L RoHS SSTPAD100 SOT-23 3L RoHS PAD1 Die PAD2 Die PAD5 Die PAD10 Die PAD20 Die PAD50 Die PAD100 Die Datasheet Spice Model Application Notes

< Back LSJ689 Press Release Linear Systems Mar 17, 2023 Ultra Low Noise P-Channel Dual JFET NEWS RELEASE CONTACT: Linear Integrated Systems, Inc. 510-490-9160 sales@linearsystems.com LINEAR INTEGRATED SYSTEMS ANNOUNCES ULTRA LOW NOISE P-CHANNEL DUAL JFET Fremont, California – June 1, 2016 – Linear Integrated Systems, a leading full-service manufacturer of specialty linear semiconductors, announces the immediate availability of its LSJ689, a 1.8 nV/Hz @ 1kHz, low-capacitance, monolithic dual P-Channel JFET. The LSJ689 serves as the P-Channel complement to the popular monolithic dual N-Channel JFET, the LSK489. This addition to Linear Systems' family of Ultra-Low-Noise JFETs provides designers with expanded options beyond traditional N-Channel JFETs. The monolithic dual construction of the LSJ689 and LSK489 offers superior solutions for tighter Idss (drain-source saturation current) matching and improved thermal tracking compared to using individually matched JFETs. As the availability of P-Channel JFETs has declined, complementary single N-Channel and P-Channel JFETs have become increasingly limited to a few industry standards. In response, Linear Systems developed the LSK170 and LSJ74 families, providing complementary N & P-Channel single JFETs. Now, the LSJ689 and LSK489 monolithic dual JFETs provide further design flexibility, with significantly lower capacitance—4 pF versus the 25 pF of LSK170 and LSJ74. The LSJ689 and LSK489 are well-suited for differential input stages in amplifier, phono, and preamplifier designs. Additional applications include voltage-controlled resistors, thermal stable source followers, sample and hold circuits, and current matched sources. The LSJ689 is available in RoHS-compliant SOT-23 6L, SOIC-A 8L, and TO-71 6L package options. The SOT-23 6L and SOIC-A 8L packages are ideal for space-constrained circuits in audio and instrumentation applications. Key Features: - Complement to the Ultra Low Noise Monolithic Dual N-Channel JFET LSK489 - Ultra Low Noise (typically 1.8 nV/Hz @ 1kHz) - Nearly Zero Popcorn Noise - Idss (drain-source saturation current) matching to 10% max - Low Offset/Tight Matching (|Vgs1 - Vgs2| = 20mV max) - Low Capacitance (Ciss = 4 pF) - High Input Impedance - High Breakdown Voltage (BVGSS = 40V Min) - Monolithic Dual (2 JFETs on one piece of silicon, offering better matching and thermal tracking) - Available in Surface Mount SOIC-A 8L and compact SOT-23 6L packages - Lead-free/RoHS Compliant Applications: - Microphone Amplifiers, Phono Preamplifiers, Audio Amplifiers, and Preamps - Discrete Low-Noise Operational Amplifiers - Battery-Operated Audio Preamps - Audio Mixer Consoles, Acoustic Sensors, Sonic Imaging - Instrumentation Amplifiers - Wideband Differential Amplifiers - High-Speed Comparators - Impedance Converters - Voltage-Controlled Resistors, Sample and Hold, Source Followers Availability: Sampling now in SOIC-A 8L, TO-71 6L, and SOT-23 6L package options. Delivery: Factory Stock About Linear Integrated Systems Founded in 1987, Linear Integrated Systems is a precision semiconductor company providing high-quality discrete components. The company’s expertise is built upon processes and products developed at Amelco, Union Carbide, Intersil, and Micro Power Systems by founder John H. Hall. Hall, a protégé of Silicon Valley legend Dr. Jean Hoerni, previously served as Director of IC Development at Union Carbide, co-founder and Vice President of R&D at Intersil, and founder/president of Micro Power Systems. Linear Systems is a U.S.-based, full-service manufacturer of specialty linear products headquartered in Fremont, California. The company’s small-signal discrete product lines are specifically designed to meet new design and second-source requirements in the audio, hybrid, medical, space, and test and measurement markets. Our product lines include BIFET Amplifiers, Bipolar Transistors, Current Regulating Diodes, JFETs, High-Speed Lateral DMOS Switches, Low Leakage Diodes, and MOSFETs. Linear Integrated Systems provides pin-for-pin replacements for more than 2,000 discrete devices, including those currently offered or previously discontinued by Interfet, Intersil, Micro Power Systems, Motorola, National, Fairchild, Toshiba, and Siliconix-Vishay. Engineers are encouraged to contact Linear Systems for assistance with applications or special testing needs.

< Back Mike Ansberry: VP of Manufacturing and General Manager Linear Systems Jan 13, 2025 Mike Ansberry Named VP of Manufacturing and General Manager at Linear Systems FOR IMMEDIATE RELEASEContact: Sales@linearsystems.com Phone: (510) 490-9160Website: www.linearsystems.com ANSBERRY NAMED VP OF MANUFACTURING AND GENERAL MANAGER AT LINEAR INTEGRATED SYSTEMS FREMONT, CA – January 13, 2025 – Linear Integrated Systems, Inc. , is excited to announce the promotion of Michael Ansberry to Vice President of Manufacturing and General Manager. Ansberry will oversee all aspects of the company’s semiconductor fabrication operations, driving strategy, innovation, and efficiency across the organization. In this expanded role, Ansberry will lead the development of strategies to select, allocate resources, and prioritize fabrication partners and vendors. He will conduct periodic SWOT analyses to ensure alignment with the company’s goals and reallocate projects based on agreed-upon metrics. Additionally, he will prioritize New Product Introduction (NPI) efforts, assigning resources to support project success, while spearheading continuous improvement initiatives to meet Linear Systems’ financial objectives. Ansberry joined Linear Systems in 2018 as Vice President of Manufacturing, bringing extensive experience in semiconductor operations. His new responsibilities as General Manager reflect his outstanding contributions and leadership. Before joining Linear Systems, Ansberry served as Director of Operations at Lumileds, a global leader in LED technology for automotive, general, and specialty lighting applications. His career also includes process engineering roles at Sipex, Micro Power Systems, and other Silicon Valley semiconductor companies, showcasing a deep understanding of both operations and engineering. “This new role is an exciting opportunity to help Linear Systems reach new heights,” said Ansberry. “I’m looking forward to strengthening our relationships with fabrication partners, streamlining operations, and continuing to deliver the world-class semiconductors our customers rely on.” Linear Systems CEO Cindy L. Johnson expressed confidence in Ansberry’s expanded role. “Mike has proven himself to be an invaluable leader in our organization. His extensive experience and dedication to excellence have been pivotal to our success. In his new role, I’m confident Mike will continue to drive innovation and operational efficiency.” Founded in 1987 by John M. Hall, Cindy L. Johnson, and John H. Hall, Linear Integrated Systems, Inc. is a privately held designer and manufacturer of small-signal discrete semiconductors based in Fremont, CA. John H. Hall, a co-founder of Intersil and the founder of Micro Power Systems, brought significant expertise and innovation to the company. Linear Systems offers a diverse product line, including Dual JFET Amplifiers , Single JFET Amplifiers , JFET Switches , DMOS High Speed Switches , Low Leakage Diodes , Current Regulating Diodes , Bipolar Transistors , MOSFETs , Voltage Controlled Resistors and BIFET Amplifiers . Visit www.linearsystems.com to download our 2024 Data Book , Cross Reference Guide , datasheets, SPICE models, application notes , and more. Stay connected and join our growing LinkedIn community for updates and insights. You can also follow us on YouTube , Facebook , Instagram and X . Contact: sales@linearsystems.com Phone: (510) 490-9160 Website: www.linearsystems.com