Renesas HZ18-2J-E

Overview

HZ18-2J-E from Renesas is a silicon planar Zener diode optimized for low-noise voltage regulation in precision analog circuits, featuring a nominal zener voltage of 17.5 V to 18.3 V at 0.5 mA test current, dynamic resistance of 80 Ω max, 400 mW power dissipation, and DO-35 glass package with navy-blue cathode band - used in reference supplies for ADCs, sensor signal conditioning, and low-drift instrumentation.

For engineers reviewing the HZ18-2J-E datasheet, HZ18-2J-E pinout, HZ18-2J-E application, or HZ18-2J-E equivalent, key selection criteria include verified zener voltage tolerance (±0.4 V), low noise performance relative to legacy HZ series, thermal coefficient behavior below 0.02 %/°C near 18 V, and compatibility with through-hole PCB assembly using standard DO-35 footprint.

Technical Context

The HZ18-2J-E operates as a two-terminal shunt regulator with DC-tested zener breakdown characteristics, designed for stable biasing in low-current (<1 mA) analog references where noise spectral density and temperature drift are critical. Its planar junction structure achieves lower leakage and reduced flicker noise versus conventional diffused Zeners.

It exhibits a zener voltage temperature coefficient of approximately +0.015 %/°C (≈+2.7 mV/°C) at 18 V, confirmed by Figure 2 in REJ03G0182-0300, and maintains ≤80 Ω dynamic impedance up to 1 mA, enabling tight regulation under varying load conditions in high-impedance feedback networks.

Key Specifications

Pinout & Package

Package: DO-35 glass axial package (JEITA code GRZZ0002ZB-A), 2.0 mm diameter × 26.0 mm length, orange body with navy-blue cathode band, mass ≈0.13 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX85C18 and 1N5245B, the HZ18-2J-E delivers verified low-noise operation and tighter leakage control in the same DO-35 form factor, making it uniquely suited for metrology-grade analog signal chains where spectral purity and long-term drift dominate selection criteria.

Availability

HZ18-2J-E is available at Aetrix Electronics and suitable for high-precision ADC reference design, low-drift sensor biasing, and instrumentation amplifier offset nulling requiring stable component supply and traceable sourcing.

Supply support for HZ18-2J-E 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog power, and mixed-signal solutions for automotive, industrial, and IoT applications.

The HZ-L Series Zener diodes were developed specifically for low-noise, high-stability voltage reference applications in precision analog systems - targeting designers needing better noise and drift performance than legacy HZ-series devices.

FAQ

What is the exact zener voltage range for HZ18-2J-E at 0.5 mA test current?

The HZ18-2J-E has a guaranteed zener voltage range of 17.5 V minimum to 18.3 V maximum when tested at I_Z = 0.5 mA, as specified on page 3 of REJ03G0182-0300. This ±0.4 V tolerance supports accurate reference design without post-manufacturing trimming. The HZ18-2J-E's tight binning enables predictable system-level accuracy in voltage-sensitive analog circuits.

Does HZ18-2J-E have a documented noise specification compared to standard Zener diodes?

Yes - the HZ18-2J-E datasheet explicitly states its noise level is approximately 1/3 to 1/10 that of the legacy HZ series, due to its silicon planar construction and optimized process. This low-noise characteristic is validated across the HZ-L family and directly impacts SNR in applications like sensor signal conditioning. The HZ18-2J-E leverages this advantage in precision analog stages where flicker noise dominates error budgets.

What is the maximum allowable reverse current before zener conduction begins in HZ18-2J-E?

The HZ18-2J-E specifies a maximum reverse leakage current (I_R) of 1 μA at V_R = 15 V, per page 2 of REJ03G0182-0300. This low leakage ensures minimal error current injection into high-impedance nodes, such as op-amp inputs or ADC reference dividers. For reliable operation, the HZ18-2J-E must be biased above its knee voltage (≥17.5 V) to enter true zener regulation.

Can HZ18-2J-E be used in surface-mount designs?

No - the HZ18-2J-E is packaged exclusively in the axial DO-35 glass case (JEITA code GRZZ0002ZB-A), intended for through-hole mounting. It has no SMD variant in the HZ-L series. Designers requiring surface-mount compatibility must select alternative Zener families such as Renesas' HZL-SMD series or third-party SOD-123 devices, noting that those lack the HZ18-2J-E's documented low-noise performance.

What is the thermal coefficient behavior of HZ18-2J-E near its nominal zener voltage?

Per Figure 2 in REJ03G0182-0300, the HZ18-2J-E exhibits a zener voltage temperature coefficient (γ_Z) of approximately +0.015 %/°C (≈+2.7 mV/°C) at 18 V, placing it near the zero-TC crossover region for silicon Zeners. This results in minimal drift over industrial temperature ranges (−40°C to +85°C), making the HZ18-2J-E especially valuable in unregulated environments where thermal stability is critical.