Renesas HZS5A3RX-E

Overview

HZS5A3RX-E from ROHM Semiconductor is a silicon epitaxial planar Zener diode designed for precision voltage regulation in stabilized power supplies, with a nominal zener voltage of 4.5–4.7 V, maximum power dissipation of 400 mW, dynamic resistance ≤100 Ω at 5 mA, and reverse current ≤1.5 µA at 1.0 V. It supports high-speed automatic insertion on 5 mm-pitch PCBs in industrial power management systems.

For engineers reviewing the HZS5A3RX-E datasheet, HZS5A3RX-E pinout, HZS5A3RX-E application, or HZS5A3RX-E equivalent, key selection criteria include zener voltage tolerance (±0.2 V), low dynamic impedance for ripple suppression, thermal stability up to 200°C junction temperature, and compatibility with automated assembly processes requiring axial leaded TO-226AA (mini-MELF) packaging.

Technical Context

This device operates as a two-terminal shunt regulator, maintaining stable output voltage by conducting reverse current above its specified zener breakdown threshold. Its epitaxial planar construction ensures tight V_Z distribution and low leakage across temperature.

The HZS5A3RX-E is characterized at I_Z = 5 mA with V_Z = 4.5–4.7 V, r_d ≤ 100 Ω, and exhibits a temperature coefficient near zero in the 4–5 V range-confirmed by Fig.2 in the official datasheet-making it suitable for reference applications where drift must be minimized.

Key Specifications

Pinout & Package

TO-226AA (mini-MELF) axial-leaded package with cathode band marking; no active pin configuration-two-terminal device with cathode (banded end) and anode (unmarked end).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4732A and BZX55-C4V7, the HZS5A3RX-E offers tighter V_Z tolerance (±0.2 V vs. ±5%), superior thermal stability up to 200°C, and mini-MELF packaging optimized for high-speed placement-making it preferred for precision industrial references where repeatability and manufacturability are critical.

Availability

HZS5A3RX-E is available at Aetrix Electronics and suitable for industrial power supply reference, overvoltage protection clamp, and linear regulator feedback applications requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for HZS5A3RX-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

ROHM Semiconductor is a Japanese semiconductor manufacturer specializing in analog, power, and sensor solutions for automotive, industrial, and consumer markets.

The HZS Series targets high-reliability voltage regulation in compact, thermally demanding environments-designed specifically for stabilized power supplies, reference circuits, and protection functions where low leakage and tight zener voltage control are essential.

FAQ

What is the exact zener voltage range for HZS5A3RX-E?

The HZS5A3RX-E has a guaranteed zener voltage range of 4.5 V to 4.7 V when tested at I_Z = 5 mA and T_a = 25°C. This ±0.2 V tolerance reflects Grade A3 specification per the HZS Series datasheet Rev 1, ensuring precise regulation without post-production calibration.

Does HZS5A3RX-E support high-temperature operation?

Yes, HZS5A3RX-E is rated for junction temperatures up to 200°C and storage temperatures from -55°C to +175°C. Its silicon epitaxial planar structure maintains stable V_Z and low r_d across this range, making it suitable for under-hood automotive modules and industrial motor drive controls.

What package type does HZS5A3RX-E use?

HZS5A3RX-E uses the TO-226AA (mini-MELF) axial-leaded package, identified by its cylindrical glass body and cathode band marking. This package supports 5 mm-pitch high-speed automatic insertion and provides better thermal dissipation than standard DO-35 devices.

How does the dynamic resistance of HZS5A3RX-E affect ripple rejection?

HZS5A3RX-E has a dynamic resistance ≤100 Ω at I_Z = 5 mA, directly determining its ability to suppress AC ripple on regulated rails. Lower r_d yields higher attenuation of input ripple-enabling stable 4.6 V references even with 100 mVpp input variation in sensitive analog subsystems.

Is HZS5A3RX-E suitable for overvoltage clamping in microcontroller I/O protection?

Yes, HZS5A3RX-E is well-suited for clamping 5 V logic lines due to its fast response, low leakage (<1.5 µA at 1.0 V), and ability to limit transient peaks to ≤5.0 V. Its 400 mW power rating handles typical ESD events when paired with series current-limiting resistors in MCU interface circuits.