Microchip Technology CDLL4615

Overview

CDLL4615 from Microsemi is a hermetically sealed, glass-encapsulated MELF (DO-213AA) Zener diode with nominal 2.0 V zener voltage, 250 µA test current, 1250 Ω maximum zener impedance at I_ZT, 5.0 µA maximum reverse leakage at 1 V, and 110 mA maximum DC zener current. It operates from −65°C to +175°C and is used for precision low-current voltage reference and regulation in high-reliability aerospace and military power supply circuits.

For engineers reviewing the CDLL4615 datasheet, CDLL4615 pinout, CDLL4615 application, or CDLL4615 equivalent, key selection criteria include its ±5% zener tolerance, 500 mW power rating at 125°C end-cap temperature, hermetic DO-213AA package, low 250 µA operating point, and MIL-PRF-19500/435 qualification for JANTXV-level reliability.

Technical Context

The CDLL4615 is a silicon planar Zener diode optimized for stable low-current voltage reference generation under extreme thermal conditions. Its metallurgically bonded construction ensures long-term stability, while the hermetic glass package enables operation up to +175°C junction temperature without degradation.

It exhibits a 1250 Ω zener impedance at 250 µA test current and maintains ≤5.0 µA reverse leakage at 1 V reverse bias - critical for low-power biasing and sensing applications where leakage-induced error must be minimized.

Key Specifications

Pinout & Package

Package: DO-213AA (MELF, SOD-80, LL34), hermetically sealed glass case with tin/lead lead finish. Axial coefficient of expansion ≈ +6 ppm/°C; requires matched COE mounting surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CDLL4615, 1N4615UR-1 offers identical electrical behavior with enhanced process controls and documentation rigor, while CDLL4616 trades 0.2 V higher regulation voltage for 1.0 µA lower leakage - enabling better signal-to-noise ratio in ultra-low-current sensor biasing.

Availability

CDLL4615 is available at Aetrix Electronics and suitable for avionics power monitoring, satellite sensor biasing, and downhole oilfield instrumentation requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CDLL4615 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 (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components for defense, aerospace, and industrial markets.

The CDLL4614–CDLL4627 series was designed specifically for precision, low-current, high-temperature voltage reference applications in mission-critical systems where hermeticity and MIL-spec compliance are mandatory.

FAQ

What is the zener voltage tolerance for CDLL4615?

The CDLL4615 has a nominal zener voltage of 2.0 V with a tolerance of ±5.0%, as specified in Note 1 of the Microsemi datasheet. This tolerance applies under thermal equilibrium at 25°C ±3°C ambient. Tighter tolerances (±2% or ±1%) are available with "C" or "D" suffixes, but CDLL4615 itself carries the standard ±5% grade.

Is CDLL4615 suitable for surface-mount assembly?

Yes, CDLL4615 uses the DO-213AA (MELF) package, which is a leadless cylindrical surface-mount device. It is explicitly described in the datasheet as having a "leadless package for surface mount." The glass body requires compatible reflow profiles and solder paste volume control to avoid cracking during thermal cycling.

What is the maximum power dissipation of CDLL4615 at 150°C end-cap temperature?

At 150°C end-cap temperature, CDLL4615's power dissipation is derated linearly from 500 mW at 125°C. With a derating factor of 10 mW/°C above 125°C, the maximum allowable power is 500 mW − (25°C × 10 mW/°C) = 250 mW. This value assumes zero thermal resistance from end-cap to ambient.

Does CDLL4615 have a specified thermal resistance junction-to-case?

No, the datasheet specifies thermal resistance "ROJEC" (junction-to-end-cap) as 100 °C/W maximum at L = 0 inch, and thermal impedance "ZJX" as 35 °C/W maximum. Junction-to-case resistance is not provided because the DO-213AA package lacks a defined case plane; thermal path is modeled from junction to end-cap ends for board-level thermal analysis.

Can CDLL4615 replace CDLL4614 in an existing design?

CDLL4615 can replace CDLL4614 only if the 0.2 V higher nominal zener voltage (2.0 V vs. 1.8 V) and 50 Ω higher zener impedance (1250 Ω vs. 1200 Ω) are acceptable in the target circuit. Reverse leakage is lower (5.0 µA vs. 7.5 µA), which may improve performance in high-impedance nodes, but voltage shift must be verified in regulation loop stability and accuracy calculations.