Addressing the demands of both smaller sizes and higher performance, Pickering Electronics recently introduced its latest high-density reed relay, the Series 125. Presented as the industry’s smallest DPST (double-pole, single-throw) reed relay, it can switch up to 1 A and 20 W, while stacking on a compact 5-mm2 pitch, which maximizes PCB real estate.
Targeting very high-density applications such as automated test equipment (ATE) switching matrices or multiplexers, the relay also performs well in mixed-signal environments. It maintains an insulation resistance of greater than 1012 Ω, and low contact resistance due to its sputtered ruthenium instrumentation-grade switches.
The Series 125 relays' 2 Form A (DPST) normally open (NO) contacts feature 3-, 5- or 12-V coils. The relays are available with sputtered ruthenium contacts for long life and high reliability, with switch type number 1 better suited for general-purpose applications at 15 W, 1 A (3- and 5-V versions) or 20 W, 1 A (12-V version). A layer of copper beneath the ruthenium helps dissipate the heat from the contact area to improve current inrush handling ability.
The 10-W, 0.5-A switch type 2 is well-suited for switching low currents and/or voltages and should be used in low-level or cold switching applications.
Shielded from Magnetics with Mu-Metal
Known for its high permeability and low magnetic remanence, mu-metal provides effective magnetic shielding, eliminating issues caused by magnetic interaction, typically measured as the percentage increase in the voltage needed to operate a relay.
Series 125 relays usually achieve an interaction figure of only 1%. By comparison, an unshielded device next to another would typically exhibit an interaction figure of around 40%. Without magnetic shielding, relays of such small size would be unsuitable for applications requiring dense packing.
The Series 125 package allows for the fitting of an optional internal diode to prevent voltage spikes caused by the inductive kickback when the relay coil is de-energized. The diode provides a path for the current to dissipate safely, protecting sensitive components from damage and reducing electrical noise.
Additional build options are available, including unique pin configurations, non-standard coil voltages/resistances, operate/de-operate times, pulse capability, special life testing under specific customer load conditions, and more.
Pickering SoftCenter technology minimizes internal stresses on the switch, and formerless coil construction enables smaller packages and maximizes magnetic efficiency, enabling extended lifetimes at operational extremes. Mu-metal screening eliminates problems due to magnetic interaction when relays are closely stacked.
The company performs 100% testing of all operating parameters. This includes dynamic contact wave-shape analysis to ensure consistency and 100% thermal cycling stress testing of the manufacturing processes, ranging from –20 to +85°C and back to –20°C, repeated three times.
