Microchip Technology CDLL4113

Overview

CDLL4113 from Microsemi is a hermetically sealed, surface-mount silicon Zener diode with nominal 19 V Zener voltage, 250 µA test current, 150 Ω Zener impedance, 0.05 µA maximum reverse leakage at 14.44 V, and 20 mA maximum Zener current. It operates in precision voltage reference and regulation circuits for industrial power supplies and analog sensor signal conditioning.

For engineers reviewing the CDLL4113 datasheet, CDLL4113 pinout, CDLL4113 application, or CDLL4113 equivalent, key selection criteria include its ±5% Zener tolerance, DO-213AA (MELF/LL34) glass package, -65°C to +175°C junction temperature range, 500 mW power dissipation at 125°C, and low-leakage performance critical for high-impedance bias networks.

Technical Context

The CDLL4113 functions as a two-terminal voltage reference device operating in reverse breakdown mode. Its Zener voltage is specified at 250 µA test current with 150 Ω dynamic impedance, and it maintains stable regulation across ambient temperatures from -65°C to +175°C due to hermetic glass packaging and metallurgical bonding.

Thermal resistance is rated at 100 °C/W (junction-to-end-cap), requiring careful PCB thermal design when operating near derated power limits. Reverse leakage remains ≤0.05 µA up to 14.44 V, enabling use in ultra-low-current biasing applications where leakage-induced error must be minimized.

Key Specifications

Pinout & Package

Package: DO-213AA (MELF/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 reference applications.

Compared with CDLL4113, 1N4113UR-1 offers identical regulation performance with enhanced qualification for defense systems, while BZX55C18 trades 1 V lower voltage and higher leakage for broader commercial availability and lower unit cost.

Availability

CDLL4113 is available at Aetrix Electronics and suitable for industrial power supplies, high-temperature sensor interfaces, and avionics voltage clamping requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CDLL4113 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 RF solutions for aerospace, defense, and industrial markets.

The CDLL4099–CDLL4135 series was designed for precision voltage reference and regulation in mission-critical systems demanding extended temperature operation, hermetic reliability, and low-parameter drift.

FAQ

What is the Zener voltage tolerance for CDLL4113?

The CDLL4113 has a nominal Zener voltage of 19 V with a tolerance of ±5%, measured at 250 µA test current and 25°C ambient temperature. This tolerance is defined per Note 1 in the official Microsemi datasheet and applies to all CDLL4099–CDLL4135 parts unless modified by a "C" (+2%) or "D" (+1%) suffix, which CDLL4113 does not carry. The CDLL4113 therefore delivers 19 V ±0.95 V under standard test conditions.

Does CDLL4113 have a specified Zener impedance, and what does it mean for circuit design?

Yes, CDLL4113 has a maximum Zener impedance (Z_ZT) of 150 Ω at 250 µA test current. This value represents the dynamic resistance in the breakdown region and directly impacts output voltage stability under varying load currents. For example, a 1 mA change in Zener current causes up to 150 mV shift in output voltage. Designers must account for this in feedback loop compensation and noise-sensitive references. The CDLL4113's 150 Ω impedance is confirmed in the Electrical Characteristics table on page 111 of the Microsemi datasheet.

What package type is used for CDLL4113, and how does it affect PCB assembly?

CDLL4113 uses the DO-213AA package-also known as MELF or LL34-a cylindrical, leadless, hermetically sealed glass case. Its axial geometry requires specialized pick-and-place tooling and reflow profile tuning due to thermal mass asymmetry. The CDLL4113's tin/lead finish supports standard Sn63/Pb37 soldering, and its +6 ppm/°C coefficient of expansion necessitates matching the PCB substrate's COE to prevent mechanical stress during thermal cycling. Mounting surface selection is explicitly called out in the CDLL4113 design data.

Can CDLL4113 replace CDLL4112 or CDLL4114 in an existing design?

CDLL4113 (19 V) is not a direct replacement for CDLL4112 (18 V) or CDLL4114 (20 V) without circuit validation, as its Zener voltage differs by ±1 V-outside typical feedback loop margins. While all three share identical package, power rating, and test current, the 1 V shift affects regulation accuracy, loop gain, and overvoltage thresholds. Substitution should only occur after verifying that the 19 V reference meets system-level tolerance budgets. The CDLL4113 datasheet lists no pin-compatible alternatives within the same family.

What is the maximum reverse leakage current for CDLL4113, and at what voltage is it specified?

The maximum reverse leakage current for CDLL4113 is 0.05 µA, specified at a reverse voltage of 14.44 V-corresponding to 76% of its nominal 19 V Zener voltage. This low leakage enables use in high-impedance bias networks where even nanoamp-level currents would introduce significant error. The value is explicitly listed in the "MAXIMUM REVERSE LEAKAGE CURRENT" column of the CDLL4113 row in the Electrical Characteristics table on page 111, and is consistent across the CDLL4099–CDLL4135 series for voltages ≥11 V.