top of page
Join the Conversation with Linear Systems
Founded in 1987 by John H. Hall, Linear Integrated Systems has a rich history rooted in innovation and precision. Building on decades of expertise honed at industry leaders like Amelco, Union Carbide, Intersil, and Micro Power Systems, we craft the highest performance semiconductors in the industry.
Our products—including ultra-low-noise JFETs, high-speed lateral DMOS switches, bipolar transistors, BIFET amplifiers, and more—empower our customers to build world-class solutions in audio, medical, industrial, military, and beyond.
At Linear Systems, we’re passionate about what we do—and we love sharing that passion in our blog. From technical deep dives and product releases to newsletters and industry insights, our blog keeps you up to date with everything happening in the world of high-performance semiconductors.
Subscribe below to get the latest blog posts, newsletters, product updates, and relevant news straight from our team in California’s Silicon Valley.
Stay connected. Sign up below!
Search
All Posts
⚡ FET Design Spotlight: Electron Beam Circuit Protection with PAD Diodes
High-voltage electron beam systems demand precision—and protecting sensitive measurement circuitry is critical to maintaining accuracy and minimizing costly downtime. In this latest FET Design Spotlight, we look at how Linear Systems PAD Diodes have provided reliable circuit protection in electron beam applications for more than 35 years. Electron Beam Circuit Protection by PAD Diodes "High-voltage applications happen to be a difficult place to involve sensitive measurement a
JC - Linear Systems
4 days ago2 min read
Linear Systems Learning Series: How to Read a JFET Datasheet
A JFET datasheet contains dozens of electrical characteristics, graphs, and performance curves—but which specifications matter most? The answer depends on your application. A designer building a low-noise microphone preamplifier may prioritize different parameters than someone designing a current source or a high-impedance sensor interface. Understanding what each specification represents is the first step in selecting the right device. 1. Noise Voltage For precision analog f
JC - Linear Systems
Aug 62 min read
Linear Systems Learning Series: Understanding 1/f Noise: Why Low-Frequency Noise Matters
Not all noise is created equal. When engineers compare low-noise devices, they often focus on the 1 kHz noise specification. While that's an important benchmark, it doesn't tell the whole story. At lower frequencies, many semiconductor devices exhibit 1/f noise, also known as flicker noise. As frequency decreases, this noise increases, making it especially important in applications that measure slow-changing or very small signals. Examples include: Precision instrumentation M
JC - Linear Systems
Jul 281 min read
JFET Design Spotlight: Phantom-Powered Piezo Preamplifier Design
Another glimpse into the creative mind of analog designer Kirkwood Rough. "‘No batteries allowed on this instrument,’ was the statement from the luthier. So, a phantom-powered preamp needed to be configured using a standard guitar cable. 'Nothing special.' First, the piezo loading had to be minimal so its charge capacity would not run out and sound 'buzzy' on the low end. Second, the piezo needed to be sensed differentially and therefore shielded. Third, no batteries could be
JC - Linear Systems
Jul 282 min read
Why Matching Matters in Dual JFETs: Improving Precision Differential Amplifier Performance
When designing a precision differential amplifier, low noise is only part of the equation. The two input transistors must behave as similarly as possible. Even small differences in electrical characteristics can introduce input offset voltage, reduce common-mode rejection (CMRR), increase temperature drift, and ultimately limit the accuracy of the entire circuit. That's why device matching is so important. Rather than pairing two individual transistors, many engineers choose
JC - Linear Systems
Jul 221 min read
Beyond Low Noise: Why Input Capacitance Matters
Last week we discussed why engineers continue to choose discrete JFETs for precision analog designs. But selecting the right JFET involves more than comparing noise specifications. For high-impedance applications such as photodiodes, hydrophones, piezoelectric sensors, condenser microphones, and precision instrumentation, input capacitance can have a significant impact on circuit performance. Higher input capacitance can reduce bandwidth, increase signal loading, and make com
JC - Linear Systems
Jul 161 min read
JFET Design Spotlight: Crafting the Perfect Bass Overdrive
We're always fascinated by the way Kirkwood Rough approaches analog circuit design. Here's another one of his design stories. "Sometimes a sound gets a grip on your senses and that happened to be the Bass lines from Moulin Rouge. They were Fat, rich, percussive and Smooth with a high octave layered presence. That started a design process that ended up being the LadyMarmalade™ effect. It had to enhance even ordered harmonics without a sharp clipping effect, even when overdrive
JC - Linear Systems
Jul 162 min read
🔦 Product Spotlight: SST211 / SD211DE Series
When switching speed and signal integrity matter, every nanosecond counts. The SST211/SD211DE Series of N-channel lateral DMOS switches is designed for high-speed, low-glitch analog switching in demanding applications where low capacitance and fast response are critical. Key Features ⚡ 1 ns maximum turn-on time ⚡ Ultra-low 0.2 pF reverse transfer capacitance (Crss) ⚡ Low rDS(on) ⚡ Low turn-on threshold voltage ⚡ Integrated Zener ESD protection ⚡ Available in TO-72 4-Lead (SD2
JC - Linear Systems
Jul 101 min read
The Tiny Component Helping Power Next-Generation AI Servers
Artificial intelligence is transforming nearly every industry, and the spotlight is often on powerful GPUs, advanced processors, and sophisticated software. But behind every AI server is an equally important layer of technology that rarely gets the attention it deserves: precision analog electronics. From routing high-speed signals to monitoring critical system functions, analog components help ensure AI servers operate with the speed, reliability, and accuracy today's data c
JC - Linear Systems
Jul 82 min read
Why Engineers Are Still Using Discrete JFETs
Integrated circuits continue to advance, but many of the highest-performance analog front ends still begin with a discrete JFET. Why? Because when you're trying to capture extremely weak signals, the input stage often determines the performance of the entire system. Engineers continue to choose discrete JFETs for applications requiring: Ultra-low noise High input impedance Low input capacitance Excellent linearity Whether designing photodiode amplifiers, hydrophone preamplifi
JC - Linear Systems
Jun 251 min read
JFET Design Spotlight: Rethinking the Audio Op-Amp
There are a lot of circuits and applications of discrete and integrated component combinations solving a myriad of tasks defined as solutions to a problem. Dad used to tell me that, "The problem isn't the problem; the definition of the problem is the problem." Dr. Gene Slottow at U of I would say, "When you think you're done with the design, throw it out and start over as your unyielding self-critic until you can't anymore, then proceed." Few first circuit iterations are "the
JC - Linear Systems
Jun 232 min read
JFET Design Spotlight 🔍 | From Early OCR Systems to 45 Years of FET Innovation
"In 1979, we teamed up at DEST Corp. to design the first desktop OCR machine for scanning standard letter and legal pages with a linear Reticon stored-charge diode array. Internal to that sensor were two identical 2048-pixel diode strings. Light would deplete the diode pixel reset charge and be read as exposure versus time through a charge integrator. Because the CMOS diode-select shift registers created substantial charge injection noise, the dark string was differentiated w
JC - Linear Systems
Jun 163 min read
JFET vs. MOSFET: Choosing the Right Technology for Precision Analog Applications
Field-effect transistors are foundational building blocks in modern electronics, but not all FETs are optimized for the same tasks. While MOSFETs dominate digital circuits, power management, and switching applications, JFETs continue to play a critical role in low-noise, high-impedance analog front ends. Understanding the strengths of each technology can help designers optimize system performance and avoid unnecessary tradeoffs. Understanding the Differences Both JFETs and MO
JC - Linear Systems
Jun 153 min read
Why High-Impedance Sensors Need More Than Just Low Noise
When engineers design front-end circuits for microphones, hydrophones, piezoelectric sensors, MEMS devices, and other high-impedance signal sources, noise is often the first specification they look at. And for good reason. Weak signals can easily be overwhelmed by amplifier noise, making low-noise devices essential for preserving signal integrity. But noise is only part of the equation. In many high-impedance applications, input capacitance can have an equally significant imp
JC - Linear Systems
Jun 102 min read
JFET Design Spotlight: Maximum Power Point Test Controller
“My daughter, during her graduate studies in renewable energy applications, once needed a tester for solar panels to find their maximum power point under real-world conditions. So, this is what dads do. The resulting tester demonstrates how different semiconductors can be selected for highly specialized tasks. For instance, the JFETs used here serve three uniquely different functions. J3 is used as a variable-resistor gain element to regulate the control oscillator output l
JC - Linear Systems
Jun 92 min read
Photodiode Preamps
In some JFET op amps such as the AD743, the input capacitance is in the order of 18 to 20 pF. In comparison, with an LSK489 dual FET, the input capacitance is in the order of 3 pF, which will be suitable for low noise photodiode applications. In this section we will see why it is important to have low equivalent input noise and low input capacitance in a photodiode preamp. A simple photodiode is shown in Figure 1 below, which uses an op amp. In the photodiode amplifier belo
JC - Linear Systems
Jun 44 min read
Better Simulation Starts with Better Device Models 🔍
Accurate simulation depends on accurate models. That’s why we’ve released new SPICE models for the LSK389, now covering all A, B, C, and D grades. These updated models are derived from real device characteristics, with key parameters like VTO and β refined based on IDSS and transconductance. This gives designers a much closer representation of how each grade actually behaves in circuit. What this means for you: More accurate circuit simulation across all LSK389 grades B
JC - Linear Systems
Jun 11 min read
The Crucial Role of Analog Front End Design in Modern Sensing Systems
Detecting weak signals starts at the analog front end. Modern sensing systems depend on capturing extremely small signals amid noisy environments. Whether the input comes from acoustic sensors, radio frequency (RF) devices, or other sensor types, the design of the front end determines the overall system’s ability to perform accurately and reliably. Precision analog components like the LSK389 dual JFET transistor play a vital role in this process. Their ultra-low noise and tig
JC - Linear Systems
May 283 min read
JFET Design Spotlight: A Single JFET Phase Splitter for audio applications
“There is sound and then there is the sound of sound.”™ In designing discrete element electronic audio circuitry, there will inevitably be a need to split a signal to a 0° and 180° phase differential. Either to drive a balanced signal to a transformer, a line signal to an XLR connector, or a differential voltage to drive a push-pull stage within a power amplifier stage, or on and on and on. Though not always needed for the task, a phase splitter will often require a zero volt
JC - Linear Systems
May 192 min read
The Hidden Role of Semiconductors in AI Infrastructure
When people talk about AI, the focus is almost always on GPUs, CPUs, and advanced nodes. But that’s only part of the story. Behind every AI system is a broader layer of semiconductors responsible for signal integrity, timing, and control — the functions that allow high-performance compute to actually work in real systems. AI Performance Depends on More Than Just Processing Power Modern AI hardware is pushing limits across the board: Faster data movement Higher board density T
JC - Linear Systems
May 132 min read
bottom of page