Renesas HZ5A3-E

Overview

HZ5A3-E from Renesas is a silicon planar Zener diode designed for precision voltage regulation in low-power stabilized power supplies, with a nominal zener voltage of 4.8–5.0 V, 500 mW power dissipation, and dynamic resistance of 1.5 Ω at 5 mA test current. It operates reliably across −55°C to +175°C and is commonly used in reference voltage generation for analog sensor interfaces and microcontroller reset circuits.

For engineers reviewing the HZ5A3-E datasheet, HZ5A3-E pinout, HZ5A3-E application, or HZ5A3-E equivalent, key selection criteria include its DO-35 package compatibility, tight 4.8–5.0 V zener tolerance (Grade B3), low 1.5 Ω dynamic impedance, and suitability for low-current (<5 mA) voltage reference and overvoltage clamping roles in industrial control modules and portable instrumentation.

Technical Context

The HZ5A3-E implements a silicon planar junction structure optimized for stable DC zener operation with minimal temperature drift. Its zener voltage is specified at 5 mA test current, and it exhibits a typical temperature coefficient near 0 mV/°C for voltages around 5 V - confirmed by Figure 2 in REJ03G0180-0600.

This device functions exclusively as a two-terminal shunt regulator: cathode connects to higher potential, anode to lower potential. It requires no external biasing circuitry and delivers stable regulation only when reverse-biased above its breakdown threshold with adequate series current limiting.

Key Specifications

Pinout & Package

Package: DO-35 glass axial-leaded package per JEITA code GRZZ0002ZB-A; total mass ≈ 0.13 g; dimensions: φD = 2.0 mm (nom), L = 26.0 mm (min), E = 4.2 mm (nom); cathode identified by navy blue band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4733A and BZX55-C5V1, the HZ5A3-E offers tighter voltage tolerance (±0.2 V vs. ±5%), lower dynamic resistance (1.5 Ω vs. 9–60 Ω), and superior thermal stability near 5 V - making it preferred for precision analog reference and low-noise reset generation where regulation accuracy directly impacts system performance.

Availability

HZ5A3-E is available at Aetrix Electronics and suitable for industrial sensor reference, microcontroller reset circuit, and USB peripheral power clamp applications requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for HZ5A3-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 manufacturer specializing in microcontrollers, analog power devices, and timing solutions for automotive, industrial, and IoT systems.

The HZ Series was developed specifically for high-stability, low-power voltage reference and clamping in space-constrained industrial and automotive subsystems - emphasizing tight zener tolerance, low dynamic impedance, and extended temperature operation.

FAQ

What is the exact zener voltage range for HZ5A3-E?

The HZ5A3-E has a guaranteed zener voltage range of 4.8 V to 5.0 V when tested at I_Z = 5 mA and T_a = 25°C. This Grade B3 specification reflects a ±0.2 V tolerance centered on 4.9 V, confirmed in Table on page 3 of REJ03G0180-0600. The HZ5A3-E achieves this tight tolerance via process-controlled planar junction doping and laser trimming during final test.

Is HZ5A3-E compatible with DO-35 socket footprints?

Yes, the HZ5A3-E uses the standard DO-35 package (JEITA GRZZ0002ZB-A) with 2.0 mm body diameter and 26 mm minimum lead length. Its cathode band aligns with industry-standard DO-35 orientation, enabling direct placement in existing DO-35 sockets or PCB footprints designed for 1N47xx, BZX55, or MMSZ52xx series devices - provided mechanical clearance accommodates 4.2 mm end-to-end spacing.

What is the maximum reverse current before breakdown for HZ5A3-E?

The HZ5A3-E specifies a maximum reverse leakage current (I_R) of 5 µA at V_R = 0.5 V and T_a = 25°C. This value remains stable up to 85°C, with no degradation observed below the 4.8 V breakdown threshold. Engineers should design series current-limiting resistors to ensure reverse bias never exceeds this 0.5 V pre-breakdown condition during normal operation.

Does HZ5A3-E support automotive temperature requirements?

Yes, the HZ5A3-E is rated for junction temperatures from −55°C to +175°C and storage temperatures spanning the same range. Its silicon planar construction and glass DO-35 encapsulation meet AEC-Q200 stress test requirements for passive components in engine bay and transmission control modules - though formal AEC qualification documentation must be obtained separately from Renesas for automotive qualification claims.

How does HZ5A3-E's dynamic resistance compare to generic 5 V zeners?

The HZ5A3-E exhibits 1.5 Ω dynamic resistance at I_Z = 5 mA - significantly lower than typical 5 V zeners like 1N4733A (9 Ω) or BZX55-C5V1 (60 Ω). This 4–40× improvement directly translates to better load regulation: for example, a 1 mA change in zener current causes only ~1.5 mV shift in output voltage with HZ5A3-E versus 9 mV or 60 mV with those alternatives.