Renesas HZS2ALLTD-E

Overview

HZS2ALLTD-E from Renesas Electronics is a silicon planar Zener diode optimized for hard-knee, low-noise voltage reference applications at low current (IZ = 1 nA to 1 mA), with nominal Zener voltage 1.8 V (min 1.6 V / max 2.0 V), dynamic impedance ZZT ≤ 350 Ω at IZT = 0.5 mA, and temperature coefficient < ±0.05 %/°C - used in precision analog front-ends and sensor biasing circuits.

For engineers reviewing the HZS2ALLTD-E datasheet, HZS2ALLTD-E pinout, HZS2ALLTD-E application, or HZS2ALLTD-E equivalent, key selection criteria include its sharp breakdown knee at sub-mA currents, low noise performance (~1/10 that of standard Zeners), MHD package compatibility with 5 mm-pitch automated insertion, and suitability for stable low-power reference design where thermal drift and dynamic impedance directly impact ADC reference accuracy.

Technical Context

The HZS2ALLTD-E employs a planar diffusion structure to achieve semilogarithmic linear VZ–IZ characteristics across 1 nA–1 mA, enabling predictable low-current regulation without soft knee degradation. Its junction design minimizes generation-recombination noise and yields lower temperature coefficient versus conventional Zeners.

It operates within a 250 mW power dissipation limit and supports junction temperatures up to 175°C, with storage range from –55°C to +175°C. The device is rated for Standard quality grade per Renesas classification, intended for office equipment, test instrumentation, and industrial electronics - not safety-critical or automotive systems.

Key Specifications

Pinout & Package

Package: MHD - molded plastic case with axial leads, cathode identified by navy-blue band; dimensions: φD = 2.0 mm (nom), L = 26.0 mm (min), mass ≈ 0.084 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HZS2ALLTD-E, both alternatives offer higher nominal Zener voltage and higher dynamic impedance, resulting in greater output variation under load and reduced suitability for sub-1 mA precision references; only HZS2ALLTD-E delivers the combination of 1.8 V hard-knee regulation, MHD auto-insert compatibility, and verified low-noise performance in its datasheet.

Availability

HZS2ALLTD-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, long-lifecycle availability, and traceable sourcing for production programs.

Supply support for HZS2ALLTD-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 Japanese semiconductor manufacturer specializing in microcontrollers, analog and power devices, and system-on-chip solutions for industrial, automotive, and communications markets.

The HZS-LL Series was designed specifically for low-noise, hard-knee Zener reference applications in test equipment, sensor interfaces, and portable instrumentation - emphasizing stability at microamp-level bias currents.

FAQ

What is the Zener voltage tolerance of HZS2ALLTD-E at 0.5 mA test current?

The HZS2ALLTD-E has a specified Zener voltage range of 1.6 V minimum to 2.0 V maximum when tested at IZ = 0.5 mA, yielding a nominal value of 1.8 V with ±0.2 V absolute tolerance. This tolerance reflects process variation across the HZS2ALL variant and is confirmed in the REJ03G0167-0300 datasheet, page 2. Designers should use the min/max values-not the nominal-for worst-case circuit analysis involving HZS2ALLTD-E.

Does HZS2ALLTD-E support operation below 1 µA, and what is its behavior at 10 nA?

Yes, HZS2ALLTD-E exhibits semilogarithmic linear VZ–IZ characteristics down to 1 nA, as documented in Figure 1 of the REJ03G0167-0300 datasheet. At 10 nA, VZ remains within the 1.6–2.0 V band with ∆VZ2 = VZ(0.05 mA) – VZ(0.001 mA) ≤ 0.6 V, confirming usable regulation even in ultra-low-power sleep modes. This makes HZS2ALLTD-E appropriate for applications where bias current must scale dynamically without reference collapse.

Is HZS2ALLTD-E qualified for automotive applications?

No, HZS2ALLTD-E is classified as a Standard quality grade device per Renesas' product grading system and is explicitly intended for computers, office equipment, test instruments, and industrial robots-not transportation or safety-critical systems. It lacks AEC-Q200 qualification, and Renesas prohibits its use in automotive applications without prior written consent. For automotive-grade Zener references, consult Renesas' "High Quality" portfolio or alternative qualified vendors.

What is the thermal resistance (RθJA) of HZS2ALLTD-E in typical PCB mounting?

The datasheet does not specify RθJA for HZS2ALLTD-E; however, Figure 3 (Power Dissipation vs. Ambient Temperature) shows derating begins at ~70°C for a 100 × 180 × 1.6 mm paper-phenol PCB. Using the 250 mW rating at 25°C and 0 mW at 175°C, approximate RθJA is 600°C/W - consistent with axial-leaded MHD packages on minimal copper. For thermal design, assume 500–700°C/W and verify with board-specific IR imaging when operating near 100 mW.

Can HZS2ALLTD-E replace standard 1N4728A in existing designs?

No - HZS2ALLTD-E is not a drop-in replacement for 1N4728A. While both are 3.3 V Zeners, HZS2ALLTD-E is a 1.8 V device (HZS2ALL variant), uses MHD axial package (vs. DO-41), and targets low-noise/low-current operation rather than general-purpose regulation. Substituting it would cause catastrophic under-voltage in circuits expecting 3.3 V. Always verify part number suffix and voltage grade before interchange - HZS2ALLTD-E must only replace other HZS2ALL-series parts.