CMR Ratio in Dual JFETs

When choosing the optimal JFET for a new circuit, a characteristic often overlooked is how the part’s design affects the rejection of unwanted inputs while amplifying the signal as accurately as possible. Single JFETs provide excellent impedance matching and low-noise amplification, but lack one important quality of their dual counterparts – dual discrete devices largely reject common signals. This important characteristic – Common Mode Rejection – means that selecting the right dual JFET can be the most cost-effective way of improving signal-to-noise ratio in a design.