UMX512

Overview

The UMX512-F is a high-power PIN diode in a hermetically sealed MELF ceramic package. It features full-face bonded chips for low-inductance construction and hard glass passivation for reliability. The device operates from HF through 2 GHz with a minimum breakdown voltage of 500 V. Key electrical parameters at 25 °C include a maximum capacitance of 1.5 pF at 50 V, a typical series resistance of 0.12 Ω at 200 mA, and a thermal resistance of 15 °C/W.

Feature Summary

• Hermetically sealed surface mount design with square-end terminations for pick-and-place operations
• Low-inductance construction utilizing full-face bonded chips
• High-reliability hard glass passivation coating on the PIN diode chip
• RoHS compliant with matte tin terminal finish

Applications

• Switching elements in magnetic resonance imaging (MRI) systems
• Attenuators and phase-shifting circuits
• Transmit/receive control in RF systems
• Switch-filter banks for frequency-hopping radios

Procurement Notes

Verify the specific ordering suffix to confirm terminal finish and packaging configuration. Standard RoHS versions utilize a matte tin finish. Confirm availability of tape and reel options if automated assembly is required. Ensure the selected variant meets the specific inductance and power handling requirements of the target application circuit.

Selection Notes

Select the UMX512-F when a balance of low series resistance and moderate capacitance is required for frequencies up to 2 GHz. Compare against the UMX509-F for lower capacitance or the UMX812-F for different resistance characteristics. Verify that the forward current pulse rating of 1 A and operating temperature range of -55 to 150 °C align with system constraints.

Part Context

The UMX512-F belongs to the Microsemi UMX502-UMX812 family of surface-mount MELF PIN diodes. This series provides various combinations of breakdown voltage, capacitance, and series resistance to suit different RF switching and attenuation needs while maintaining a consistent hermetic package form factor.

Replacement Considerations

Direct substitutes within the same family include the UMX509-F and UMX812-F. These alternatives offer similar 500 V breakdown voltages but differ in capacitance and series resistance values. Verify pin compatibility and thermal performance before substitution.