REED RELAYS FOR LOW CAPACITANCE

In many switching applications, there can be a need for low capacitance, for example, wide bandwidth A.T.E. switching matrices, attenuator switching or any other applications where exceptionally low levels of inter-terminal capacitances are required. Pickering’s Series 103 offers two different designs to give the best performance depending on the application requirements. With any standard reed relay, the switch is fitted inside a coil of similar length resulting in the coil and the switch blades acting like plates in a capacitor, along with the addition of fringing capacitance from internal connections and the magnetic screen.

The 103 and 103M versions minimize this with a much shorter coil, low permittivity potting compounds and where fitted, a modified magnetic screen. This results in closed switch to coil capacitance typically 0.4pF, compared to typically 2.5pF for a standard SIP/SIL reed relay. The 103G and 103GM utilize a coaxial screen between the switch and the coil which when driven by an active guard, results in closed switch to coil capacitance of typically 0.1pF.

The option of an internal magnetic screen ensures correct operation if stacking side by side is required and all types use instrumentation grade reed switches to ensure excellent low-level performance and long life.