Description and Applications
The MA4E2508 SurMountä Anti-Parallel Diode Series are Silicon Low, Medium & High Barrier Schottky Devices fabricated with the patented Heterolithic Microwave Integrated Circuit (HMIC) process. HMIC circuits consist of Silicon pedestals which form diodes or via conductors embedded in a glass dielectric, which acts as the low dispersion, low loss, microstrip transmission medium. The combination of silicon and glass allows HMIC devices to have excellent loss and power dissipation characteristics in a low profile, reliable device.
The Surmount Schottky devices are excellent
choices for circuits requiring the small parasitics of a beam lead device coupled with the superior mechanical performance of a chip. The SurMount structure employs very low resistance silicon vias to connect the Schottky contacts to the metalized mounting pads on the bottom surface of the chip. These devices are reliable, repeatable, and a lower cost performance solution to conventional devices. They have lower susceptibility to electrostatic discharge than conventional beam lead Schottky diodes.
The multi-layer metalization employed in the fabrication of the Surmount Schottky junctions includes a platinum diffusion barrier, which permits all devices to be subjected to a 16-hour non-operating stabilization bake at 300°C.
The “ 0502 ” outline allows for Surface Mount placement and multi- functional polarity orientations.
The MA4E2508 Family of SurMount Schottky diodes are recommended for use in microwave circuits through Ku band frequencies for lower power applications such as mixers, sub-harmonic mixers, detectors and limiters. The HMIC construction facilitates the direct replacement of more fragile beam lead diodes with the corresponding Surmount diode, which can be connected to a hard or soft substrate circuit with solder.

Features
● Extremely Low Parasitic Capitance and Inductance
● Surface Mountable in Microwave Circuits, No Wirebonds Required
● Rugged HMIC Construction with Polyimide Scratch Protection
● Reliable, Multilayer Metalization with a Diffusion
● Barrier, 100% Stabilization Bake (300°C, 16 hours)
● Lower Susceptibility to ESD Damage