Microchip Technology 1N4465CUS

Overview

1N4465CUS from Microsemi is a hermetically sealed, voidless glass MELF surface-mount Zener diode rated for 1.5 W steady-state power dissipation, with a nominal Zener voltage of 10.0 V at 25 mA test current, ±5% tolerance (C = ±2%), and maximum dynamic impedance of 5 Ω at I_ZT. It operates across –65 °C to +175 °C junction temperature and is qualified to MIL-PRF-19500/406 at JANTXV level for high-reliability voltage regulation in aerospace power conditioning.

For engineers reviewing the 1N4465CUS datasheet, 1N4465CUS pinout, 1N4465CUS application, or 1N4465CUS equivalent, key selection criteria include its military-grade hermetic glass construction, 10 V Zener regulation with low ZZT, thermal resistance of 20 °C/W (junction-to-end cap), and compatibility with automated SMT assembly per EIA-481-B tape-and-reel.

Technical Context

This device functions as a precision shunt voltage regulator in feedback loops and reference circuits, leveraging a metallurgically bonded tungsten slug within a hard-glass MELF envelope to ensure stable breakdown characteristics under thermal stress and radiation exposure. Its Category I internal bond structure and triple-layer passivation support operation in harsh environments where long-term parametric drift must be minimized.

The 1N4465CUS exhibits a Zener knee current (I_ZK) of 0.25 mA, maximum reverse leakage (I_R) of 0.25 µA at 8.0 V, and forward voltage of 1.0 V at 200 mA - confirming robust bidirectional blocking capability and low conduction loss in clamp or protection roles.

Key Specifications

Pinout & Package

Package: A (D-5A) MELF - hermetically sealed voidless glass body with tungsten slugs, cathode indicated by single polarity band, tin/lead or RoHS-compliant matte tin terminations, weight 193 mg.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage regulation applications.

Compared with 1N4465US and SMF10A, the 1N4465CUS uniquely delivers ±2% DC regulation stability, hermetic reliability, and low-impedance reference performance - making it irreplaceable in precision, high-temperature, or radiation-exposed applications where long-term parametric consistency is mandatory.

Availability

1N4465CUS is available at Aetrix Electronics and suitable for avionics power reference, satellite bus regulation, and downhole telemetry supply requiring stable component supply with full traceability and MIL-spec compliance.

Supply support for 1N4465CUS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi Corporation (now part of Microchip Technology) designs high-reliability analog and mixed-signal semiconductors for aerospace, defense, and industrial markets, with emphasis on radiation-hardened, high-temperature, and mil-spec qualified components.

The 1N4465CUS belongs to Microsemi's military-qualified Zener diode family engineered specifically for voltage regulation in mission-critical systems where failure is not an option - including launch vehicle power supplies, orbital instrumentation, and nuclear facility controls.

FAQ

What is the Zener voltage tolerance of the 1N4465CUS?

The 1N4465CUS has a Zener voltage tolerance of ±2%, indicated by the "C" suffix in its part number. This is tighter than the standard ±5% tolerance found in the base 1N4465US variant. The 10.0 V nominal Zener voltage is guaranteed to fall between 9.8 V and 10.2 V at the specified test current of 25 mA, enabling higher-accuracy voltage references in precision analog circuits.

Is the 1N4465CUS RoHS compliant?

The 1N4465CUS is available in RoHS-compliant versions with matte tin terminations, but only for commercial-grade units. Military-grade variants (JAN, JANTX, JANTXV, JANS) retain Sn/Pb terminations to meet MIL-PRF-19500/406 requirements. The "e3" marking denotes RoHS compliance and appears only on commercial-grade reels - verify ordering code suffixes with Aetrix Electronics for compliance-critical programs.

What is the maximum continuous Zener current (I_ZM) for the 1N4465CUS?

The maximum continuous Zener current (I_ZM) for the 1N4465CUS is 150 mA at 25 °C ambient, derived from its 1.5 W power rating and 10 V Zener voltage (P = V × I). This value decreases linearly with rising case temperature per the derating curve in Figure 2 of the datasheet, reaching zero at approximately 115 °C case temperature - requiring careful thermal design in high-power applications.

Does the 1N4465CUS require a heatsink for 1.5 W operation?

The 1N4465CUS does not require an external heatsink for 1.5 W operation if mounted directly to ≥1 in² of 2-oz copper on FR-4 PCB, leveraging its 20 °C/W junction-to-end-cap thermal resistance. However, sustained 1.5 W dissipation at elevated ambient temperatures (>70 °C) necessitates additional copper area or thermal vias - the end-cap design allows soldering to thermal pads, unlike standard SOD packages.

How is the cathode identified on the 1N4465CUS MELF package?

The cathode of the 1N4465CUS is identified by a single dark band marked on the glass body - consistent with JEDEC-standard polarity marking for MELF diodes. This band aligns with the cathode terminal during automated placement and must be oriented toward the higher-potential node in Zener regulator configurations. No alphanumeric marking is present; visual band inspection is the sole identification method.