MML4401-GM3/TR

RF Diode Overview

The MML4401-GM3/TR is a silicon limiter diode from the MML4400 series, manufactured by Microchip Technology. It features a non-hermetic plastic surface-mount package (GM3) designed for MRI applications. The device operates with a peak reverse voltage of 75V and exhibits a maximum capacitance of 1.5pF at 0V bias and 1MHz. At 100mA forward current and 100MHz frequency, the resistance is 2.5Ω maximum. It functions as two independent PIN diodes in an anti-parallel configuration within the GM3 package. The component supports an operating temperature range from -55°C to 150°C and is RoHS compliant.

RF Diode Feature Summary

• Designed specifically for passive receiver protection in MRI environments against high-RF energy fields.
• Features low insertion loss in both on-state and off-state conditions to preserve receiver noise figure.
• Capable of passive switching for surface-coil detuning and blocking circuits without requiring a switch driver.

RF Diode Applications

• MRI receiver protection for low-noise amplifiers (LNA).
• Passive switching of surface-coil detuning circuits.
• Passive switching of surface-coil blocking circuits.

RF Diode Procurement Notes

Verify the specific ordering suffix required for tape-and-reel packaging when placing orders. Confirm that the GM3 package variant matches the intended PCB footprint and assembly requirements. Ensure compliance with RoHS directives relevant to the target market. Check for any recent Product Change Notifications regarding manufacturing sites or material composition updates before finalizing procurement plans.

RF Diode Selection Notes

Select this component for applications requiring fast surface-mount limiting with low magnetic construction. The GM3 package provides an anti-parallel topology suitable for differential signal paths. Consider the 75V breakdown voltage and 1.5pF capacitance limits relative to the system's RF environment. Verify thermal resistance specifications if significant power dissipation is expected during operation.

RF Diode Part Context

The MML4401-GM3 belongs to the MML4400 series of RoHS-compliant fast surface mount MRI protection diodes. This series includes variants like MML4402 and MML4403 with different resistance characteristics. The GM3 package distinguishes itself by offering an anti-parallel configuration for dual-diode functionality in a single surface-mount footprint.

RF Diode Replacement Considerations

Direct substitutes within the same series include MML4401-GM2, which offers identical electrical parameters but in a different package outline. Other series members such as MML4402-GM3 or MML4403-GM3 provide lower resistance values but may alter circuit impedance matching. Verify package compatibility and pinout alignment before substituting.