Renesas HZ9A1L-E

Overview

HZ9A1L-E from Renesas is a silicon planar Zener diode optimized for low-noise voltage regulation in precision analog circuits, with a nominal zener voltage of 7.7–8.1 V, maximum power dissipation of 400 mW, dynamic resistance of 60 Ω at 0.5 mA test current, and junction temperature rating up to 175°C - deployed in reference voltage sources for instrumentation amplifiers.

For engineers reviewing the HZ9A1L-E datasheet, HZ9A1L-E pinout, HZ9A1L-E application, or HZ9A1L-E equivalent, key selection criteria include zener voltage tolerance (±0.2 V), low noise performance (1/3–1/10 lower than standard HZ series), DO-35 package compatibility, and thermal stability across −55°C to +175°C storage range.

Technical Context

This device operates as a two-terminal shunt regulator using silicon planar junction technology, delivering stable reverse-biased breakdown with low dynamic impedance and minimal voltage drift over temperature. Its noise reduction is achieved through optimized doping and junction geometry, not external filtering.

The HZ9A1L-E exhibits a zener voltage temperature coefficient near zero (≈0 mV/°C) within its 7.7–8.1 V range, confirmed by Figure 2 of REJ03G0182-0300, and maintains ≤1 μA reverse leakage at VR = 2.0 V per electrical characteristics table.

Key Specifications

Pinout & Package

DO-35 glass axial package with 2 mm diameter body, 26 mm overall length, and 0.5 mm lead diameter; cathode identified by navy blue band; mass ≈0.13 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4733A and BZX84-C8V2, the HZ9A1L-E provides optimal trade-off of 8.0 V nominal output, ultra-low noise, and axial DO-35 compatibility for through-hole prototyping and legacy industrial designs - neither alternative matches its combined low-noise and 7.7–8.1 V specification.

Availability

HZ9A1L-E is available at Aetrix Electronics and suitable for precision voltage reference, low-noise analog biasing, and industrial sensor excitation requiring stable component supply with full traceability and long-life support.

Supply support for HZ9A1L-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 specializing in microcontrollers, analog power, and mixed-signal solutions for automotive, industrial, and infrastructure markets.

The HZ-L Series Zener diodes were designed specifically for low-noise, high-stability voltage reference applications in test equipment, medical instrumentation, and precision measurement systems - emphasizing noise reduction over generic regulation.

FAQ

What is the exact zener voltage range for HZ9A1L-E?

The HZ9A1L-E has a guaranteed zener voltage range of 7.7 V to 8.1 V when tested at I_Z = 0.5 mA and T_a = 25°C, as specified in the Electrical Characteristics table on page 2 of REJ03G0182-0300. This 0.4 V window reflects tight process control for precision reference use, and the HZ9A1L-E must be operated within this range to meet its low-noise and low-impedance specifications.

Does HZ9A1L-E have a specified noise spectral density?

The HZ9A1L-E datasheet does not provide numerical noise spectral density (nV/√Hz) values, but states its noise level is "approximately 1/3–1/10 lower than the HZ series" - a relative improvement verified across the 10 Hz–10 kHz band in Renesas characterization. The HZ9A1L-E achieves this via optimized planar junction design, and users should measure total integrated noise in-circuit since external capacitance and layout dominate broadband contribution.

Can HZ9A1L-E replace standard 1N4733A in existing designs?

No - the HZ9A1L-E cannot directly replace 1N4733A due to different zener voltage (7.7–8.1 V vs. 5.1 V), lower power rating (400 mW vs. 1 W), and distinct noise-performance focus. While both are DO-35 Zeners, substituting HZ9A1L-E into a 5.1 V circuit would cause regulation failure. The HZ9A1L-E is intended for new designs targeting 8 V low-noise references, not retrofits of legacy 5.1 V supplies.

What is the maximum recommended zener current for continuous operation of HZ9A1L-E?

The HZ9A1L-E is rated for 400 mW maximum power dissipation at T_a = 25°C, so the absolute maximum continuous zener current is ~49 mA at 8.1 V (P = V × I). However, the datasheet specifies dynamic resistance and voltage tolerance at I_Z = 0.5 mA, and stable low-noise operation is best maintained between 0.5 mA and 5 mA. Exceeding 10 mA risks thermal drift and accelerated aging - the HZ9A1L-E performs optimally in the 1–3 mA range for precision references.

Is HZ9A1L-E suitable for automotive under-hood applications?

Yes - the HZ9A1L-E supports junction temperatures up to +175°C and storage from −55°C to +175°C, meeting extended temperature requirements for non-safety-critical automotive under-hood modules such as engine control sensor interfaces and cabin climate controllers. However, Renesas explicitly excludes this part from safety-related systems (e.g., airbag, braking); the HZ9A1L-E is qualified for general automotive use but not AEC-Q200 stress-tested - verify qualification status with Renesas for production deployment.