top of page

LSK170 Press Release

Mar 17, 2023

Direct Replacement for Toshiba 2SK170


FREMONT, Calif. January 25, 2005 Linear Integrated Systems, a leading full-service manufacturer of specialty linear semiconductors, announces the immediate availability of its LSK170 series of JFETs, optimized to provide low noise at both high and low frequency with a narrow range of IDSS and low capacitance.  The LSK170's low noise to capacitance ratio and narrow range of low value IDSS provide solutions for low noise applications which cannot tolerate high values of capacitance or wide ranges of IDSS.

The LSK170 offers a voltage noise (en) of 1nv/hz @ 1khz, 2nv/hz @ 10hz typical and a High Gain (yfs, 22ms), with only 22pf of capacitance (Ciss).  This series has three grades of IDSS range: 2.6-6mA, 6.0-12mA, and 10-20mA.

The narrow ranges of IDSS binning with the LSK170 promote ease of design tolerancing, particularly in low voltage applications.  The LSK170 is ideal for portable battery operated applications, and features high BVDSS for maximum linear headroom in high transient program content amplifiers.  The series has a uniquely linear VGS transfer function for a stability that is highly desirable, particularly for audio front-end preamplifiers.

The device is available in surface mount SOT-23 and thru-hole TO-92 packages.  The surface mount version of the LSK170 series creates new opportunities for engineers seeking to design lower noise circuits in compact embeddable applications where shielding and space is critical and are not supported with the traditional TO-92 package.  The LSK170 series is a pin for pin replacement of the Toshiba 2SK170 and improved functional replacement for the Interfet IF1320, IF1330, IF1331, and IF4500.

Superior Performance, Domestic Source

The LSK170 is specifically designed for low noise, high input impedance applications within the audio, instrumentation, medical and sensors markets.

"Our new LSK170 series feature a unique low noise profile having nearly zero popcorn noise," says Dr. John Hall, Linear Integrated Systems founder and president.  "Utilizing large scale integrated circuit technology to build the LSK170 series allows LIS to achieve the goals of high transconductance, low noise and a low value of gate to drain capacitance.  This combined with recent developments in Ion Implant technology optimized for low noise has allowed the creation of this state-of-the-art product."

Linear Integrated Systems domestic in-factory stock guarantees short lead times, ensuring no disruption in production schedules.

Summary of Features:

  • Low Noise (en <1 nv/hz @ 1khz, 2 nv/hz @ 10hz typ)

  • Low Capacitance (20pf typ)

  • High Input Impedance

  • Availability in narrow IDSS grades/ranges (2.6-6mA, 6.0=12mA and 10-20mA)

  • High Gain (Yfs = 22mS typ)

  • High Breakdown Voltage (BVGSS = 40V Min)

  • Improved pin for pin replacement for Toshiba 2SK170

  • Surface mount SOT23 version (not offered by Toshiba 2SK170)

  • Improved functional replacement for Interfet IF1320, IF1330, IF1331, and IF4500


Audio amplifiers and preamps, discrete low-noise operational amplifiers, battery-operated audio preamps, guitar pickups, effects pedals, microphones, audio mixer consoles, acoustic sensors, sonobouys, hydrophones, chemical and radiation detectors, instrumentation amplifiers, accelerometers, CT scanners input stages, oscilloscope input stages, electrometers and vibrations detectors.

Price: LSK170A TO-92 3L = $4.46 (1,000+ pieces), LSK170A SOT-23 3L = $4.62 (1,000+ pieces)

Availability:  Sampling now in SOT-23 and TO-92 package options

Delivery:  Factory Stock

About Linear Integrated Systems

Linear Integrated Systems, Inc. is a U.S.-based, full service manufacturer of specialty linear products founded in 1987 with headquarters in Fremont, California.  The company's small-signal discrete product lines are specifically designed to service the new design and second-source requirements of customers in the audio, hybrid, medical, space, test and measurement markets.

Linear Integrated Systems supplies pin for pin replacements for more than 2,000 discrete devices currently offered or discontinued by Interfet, Intersil, Micro Power Systems, Motorola, National, Fairchild, Toshiba, and Siliconix-Vishay.

Linear Integrated Systems has more than 35 years of design and process expertise in JFET and transistor manufacturing.  The company’s founder, Dr. John Hall, has an established track record of leadership within various segments of the semiconductor industry, including the founding of Intersil and Micro Power Systems, development of the first 1 Volt CMOS digital watch and numerous related semiconductor patents.

Engineers are invited to contact Linear Integrated Systems for assistance with application or special testing issues.

Phone 510-490-9160

Fax: 510-353-0261



bottom of page