Renesas HZ5ALLTD-E

Overview

HZ5ALLTD-E from Renesas Electronics is a silicon planar Zener diode optimized for hard-knee, low-noise voltage reference applications at low currents (IZ = 1 nA to 1 mA), with a nominal Zener voltage of 4.5 V (min 4.3 V, max 4.7 V), dynamic impedance of 380 Ω at IZT = 3.0 mA, and temperature coefficient of –0.02 mV/°C - used in precision analog front-ends and sensor biasing circuits.

For engineers reviewing the HZ5ALLTD-E datasheet, HZ5ALLTD-E pinout, HZ5ALLTD-E application, or HZ5ALLTD-E equivalent, key selection criteria include its sharp breakdown knee at sub-mA currents, ultra-low noise performance (~1/10 that of standard Zeners), DO-35 package compatibility, and suitability for low-power, high-stability reference designs where thermal drift and dynamic impedance directly impact ADC accuracy and signal chain integrity.

Technical Context

The HZ5ALLTD-E employs a planar diffusion process to achieve semi-logarithmic VZ–IZ linearity across 1 nA–1 mA, enabling stable regulation even under microampere bias conditions. Its hard-knee characteristic minimizes transition-region uncertainty, critical for low-current reference stability.

Designed specifically for low-noise operation, it exhibits reduced avalanche-induced noise versus conventional Zeners due to controlled junction geometry and doping profile - verified by measured noise spectral density and dynamic impedance below 400 Ω at 3 mA.

Key Specifications

Pinout & Package

Package: DO-35 (JEITA code GRZZ0002ZB-A), glass axial leaded, cathode identified by navy-blue band, body color verdure, mass 0.13 g, dimensions φD = 2.0 mm max, L = 26.0 mm min, E = 4.2 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5225B and BZX55C4V3, the HZ5ALLTD-E delivers uniquely low noise and hard-knee behavior at microampere currents - making it irreplaceable in applications demanding sub-millivolt stability and high SNR below 100 µA, whereas alternatives require higher bias and exhibit greater thermal drift and noise.

Availability

HZ5ALLTD-E is available at Aetrix Electronics and suitable for industrial sensor biasing, precision ADC reference design, and low-power IoT node regulation requiring stable component supply, consistent parametric performance, and long-lifecycle availability.

Supply support for HZ5ALLTD-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 Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and connectivity solutions for automotive, industrial, and enterprise systems.

The HZ-LL Series, including HZ5ALLTD-E, was designed specifically for low-noise, hard-knee Zener reference applications in precision analog signal chains - targeting sensor interfaces, metrology equipment, and battery-constrained instrumentation where traditional Zeners fail to meet noise and drift requirements.

FAQ

What is the Zener voltage tolerance of HZ5ALLTD-E at 0.5 mA test current?

The HZ5ALLTD-E has a specified Zener voltage range of 4.3 V minimum to 4.7 V maximum when tested at I_Z = 0.5 mA, yielding a nominal 4.5 V with ±0.2 V absolute tolerance. This tight spread supports high-accuracy biasing without post-manufacturing sorting or trimming. The HZ5ALLTD-E's guaranteed limits are validated per Renesas REJ03G0183-0300 Rev.3.00 test conditions and apply across the full industrial temperature range.

Does HZ5ALLTD-E support operation below 1 µA, and what is its behavior in that region?

Yes - the HZ5ALLTD-E exhibits semi-logarithmic V_Z–I_Z linearity down to 1 nA, confirmed in Figure 1 of the official datasheet. At 100 nA, V_Z remains within ±15 mV of its 0.5 mA value, enabling stable reference generation in nanoampere-biased circuits like photodiode transimpedance amplifiers. The HZ5ALLTD-E's hard-knee design ensures predictable turn-on without soft rolloff, unlike standard Zeners.

What is the maximum allowable power dissipation for HZ5ALLTD-E in free-air conditions?

The HZ5ALLTD-E has an absolute maximum power dissipation of 250 mW at T_a = 25°C, derating linearly to zero at 175°C junction temperature. In typical DO-35 PCB mounting (100 × 180 × 1.6 mm phenolic board), usable dissipation drops to ~120 mW at 70°C ambient - sufficient for 4.5 V × 25 mA operation. Exceeding this risks irreversible junction degradation, and the HZ5ALLTD-E must be operated within these limits per Renesas Absolute Maximum Ratings table.

How does the temperature coefficient of HZ5ALLTD-E compare to standard 4.3 V Zeners?

The HZ5ALLTD-E features a temperature coefficient of –0.02 mV/°C, approximately 100× lower in magnitude than typical 4.3 V Zeners (e.g., BZX55C4V3 at +2.5 mV/°C). This translates to <±0.35 mV total drift over –25°C to +85°C, versus >±20 mV for standard parts. That ultra-low γ_Z is intrinsic to the HZ-LL Series' planar process and makes the HZ5ALLTD-E uniquely suited for untrimmed, wide-temperature reference designs.

Is HZ5ALLTD-E RoHS compliant and lead-free?

Yes - the HZ5ALLTD-E conforms to EU RoHS Directive 2011/65/EU and is lead-free, as confirmed by Renesas' environmental compliance documentation and material declarations. The DO-35 glass package contains no restricted substances above threshold limits, and the device is rated for "Standard" quality grade applications per Renesas' classification system - suitable for industrial, office, and communications equipment per Notice #7 in the datasheet.