Nexperia USA Inc. NZX18C,133

Overview

NZX18C from Nexperia is a single Zener diode in a hermetically sealed SOD27 (SC-40) glass package, designed for precision voltage regulation and reference functions in low-power analog circuits. It delivers a nominal Zener voltage of 18.1 V to 19.0 V at 5 mA test current, with differential resistance ≤55 Ω, reverse leakage ≤0.05 µA, total power dissipation up to 500 mW, and operates across −65 °C to +175 °C ambient temperature.

For engineers reviewing the NZX18C datasheet, NZX18C pinout, NZX18C application, or NZX18C equivalent, this device is selected for stable low-current voltage clamping, analog signal conditioning, and overvoltage protection where tight tolerance, low thermal drift, and long-term reliability in harsh environments are required.

Technical Context

The NZX18C operates as a two-terminal, silicon-based Zener diode relying on controlled reverse-biased avalanche breakdown to maintain a stable reference voltage. Its 18.1–19.0 V nominal Zener voltage is specified at I_Z = 5 mA, with a typical temperature coefficient near zero crossing in this range, minimizing drift over temperature.

It exhibits low differential resistance (≤55 Ω), enabling stable regulation under small load variations, and ultra-low reverse leakage (≤0.05 µA at V_R = 12.6 V), critical for high-impedance bias networks and battery-powered sensor references.

Key Specifications

Pinout & Package

The NZX18C uses a hermetically sealed axial-leaded SOD27 (SC-40) glass package with 2 terminals. The black band marks the cathode end. Leads are tinned copper-clad steel, suitable for wave or hand soldering per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX55-C18 and MMSZ5245B, NZX18C offers superior thermal robustness (175 °C T_j, 380 K/W R_th(j-a)) and hermetic reliability, making it preferred for mission-critical analog references and high-temperature clamping where long-term parametric stability is non-negotiable.

Availability

NZX18C is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive ECU protection circuits, and low-power precision reference designs requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for NZX18C 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete, logic, and MOSFET solutions, serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.

The NZX series targets general-purpose Zener regulation with emphasis on hermetic stability, wide temperature operation, and tight voltage tolerance - engineered for analog signal integrity in demanding environments.

FAQ

What is the maximum continuous reverse current the NZX18C can handle without degradation?

The NZX18C is rated for a maximum forward current of 250 mA per Absolute Maximum Ratings (Table 5), but as a Zener diode, its safe continuous reverse current is determined by power dissipation limits. At 25 °C ambient, it supports up to 27.8 mA (500 mW ÷ 18.1 V) continuously; derating is required above 25 °C using the 380 K/W thermal resistance value.

Does the NZX18C have a specified temperature coefficient, and how does it affect regulation accuracy?

Per Figure 4 in the datasheet, the NZX18C (within the NZX16–NZX18 range) exhibits a near-zero temperature coefficient around 0 mV/K at I_Z ≈ 5 mA, with typical variation of ±0.5 mV/K across −40 °C to +125 °C. This minimizes voltage drift in precision references, delivering <±0.15 V total shift over the full operating range.

Can NZX18C be used in parallel for higher power handling?

No - Zener diodes exhibit negative temperature coefficients below ~5 V and positive above ~5 V, but even within the same batch, minor V_Z mismatches cause current hogging. Parallel connection risks thermal runaway and premature failure; for higher power, use a single higher-rated Zener or active regulation instead.

Is the SOD27 package lead-free and RoHS-compliant?

Yes - Nexperia confirms the NZX18C meets RoHS Directive 2011/65/EU and REACH SVHC requirements. The leads are matte tin-plated copper-clad steel, with no lead content in solderability layers or glass encapsulant, and full compliance documentation is available via Nexperia's product change notifications.