A Design Guide to the LSK389 Dual and LSK170 Single JFETs When designing ultra-low-noise analog front ends, device selection matters. Whether you're building instrumentation, audio, or sensing systems, the transistor you choose can directly impact signal integrity, stability, and overall system performance. Two of the most trusted solutions for engineers worldwide are the LSK389 dual JFET  and LSK170 single JFET  — precision components engineered for applications where noise, matching, and...

JFET Design Spotlight 🎸 “JFET Guitar Wah Pedal — Look Ma, No Inductors!”   The variable band pass filter for musical voicing effects most notably, the Cry Baby from VOX, became famously known as a WAH Pedal. The original WAH used a 500mH inductor in a feedback loop to produce a variable filter with foot-pedal potentiometer activation. Issues with this pedal were, few were much alike. This design variation of the WAH effect is to eliminate the inductor having varied Q’s making most all Wah...

“An accelerometer is typically a capacitive transducer and varies Cacc with acceleration rate. A common problem with resident current fed accelerometer preamps is excessive DC offset drift when used up to 100 C. The object here was to keep the output bias voltage within +/- 25% of the 10-volt setting. The LS5906 Low bias Dual JFET addresses this temperature dependency by a unique internal DIE coupling in its construction. In this circuit, compensation of J1’s gate current over temperature...