Linear Systems Ultra-Low-Noise JFETs
Linear Systems presents a full line of single, dual, N-Channel and P-Channel ultra-low-noise JFETs to create low-noise, high-performance applications ranging from sensors to audio amplifiers. Members of the company’s design and production staff each have over 40 years’ experience making these parts, and as a group they are the most talented working in this area today.
Linear Systems has unique expertise in designing and producing monolithic dual JFETs, with related intellectual property dating back to the beginning of the company over 30 years ago. Monolithic dual JFETs have a very real and significant thermal tracking advantage over two discrete die selected for match in the same package. Selecting two dice for VGS match isn’t hard, but it is far more difficult to select VGS match over a temperature span.
Linear Systems’ monolithic dual designs overcome the typical problem with this approach – parasitic capacitance – to create the highest performance parts in their class. Our proprietary JFET designs also create the lowest noise parts of their type in the industry.
Linear Systems offers a wide range of special testing and selection options for these parts.
This line of ultra-low-noise JFETs includes:
The LSK389
The LSK389 is Linear Systems’ premier ultra-low-noise part. This monolithic, N-Channel dual JFET is available in four Idss grades and is used in a variety of ultra-high-end audio and sensor applications. In the SOIC package, the LSK389 is available with 100 percent noise testing, so each part is individually tested to meet specified noise levels.
Datasheet Application Note SPICE Model
The LSK489
The LSK489 is high-performance monolithic dual N-Channel JFET that provides excellent low-noise performance in a design that has very low input capacitance (Ciss). The part is used in many ultra-high- end applications, including in the front-end amplification of the Large Scale Synoptic Telescope (LSST), the world’s largest camera.
Datasheet Application Note SPICE Model
The LSK170
The LSK170 is the single counterpart to the LSK389 and achieves similar ultra-low-noise performance. Like all high-performance Linear Systems single JFETs, the LSK170 uses a gold backside contact to enhance low noise and low leakage performance. The LSK170 is used in a variety of applications ranging from studio microphones to sonobuoys.
Datasheet Application Note SPICE Model
The LSJ74
The LSJ74 is the P-Channel single counterpart to the LSK170 and also achieves similar ultra-low-noise performance. This part enables engineers to produce complementary N-Channel/P-Channel designs using single JFETs.
Datasheet Application Note SPICE Model
The LSK189
The LSK189 is the single counterpart to the LSK489 and is also an ultra-low-noise, low input capacitance design choice. Like all high-performance Linear Systems single JFETs, the LSK189 uses a gold backside contact to enhance low noise and low leakage performance.
Datasheet Application Note SPICE Model
The LSJ689
The LSJ689 is the monolithic dual P-Channel counterpart to the LSK489. The only dual P-Channel JFET currently in production with any company, this part enables engineers to produce complementary N- Channel/P-Channel designs using dual JFETs.