Renesas HZ20-3LTD-E

Overview

HZ20-3LTD-E from Renesas Electronics is a silicon planar Zener diode optimized for low-noise voltage regulation in precision analog circuits, featuring a nominal zener voltage of 20.2–21.1 V at 0.5 mA test current, 100 Ω dynamic impedance, 400 mW power dissipation, and DO-35 glass package with navy-blue cathode band. It serves as a stable reference in low-drift power supplies and sensor biasing networks.

For engineers reviewing the HZ20-3LTD-E datasheet, HZ20-3LTD-E pinout, HZ20-3LTD-E application, or HZ20-3LTD-E equivalent, key selection criteria include its low-noise performance (≈1/3–1/10 of standard HZ series), tight zener voltage tolerance, temperature coefficient of ≈+0.06 %/°C near 20 V, and suitability for stabilized reference designs requiring minimal thermal drift and leakage.

Technical Context

This device operates as a two-terminal voltage reference using avalanche breakdown in a silicon planar junction. Its low noise stems from optimized doping profile and passivation, reducing flicker and shot noise components critical in audio preamps and instrumentation amplifiers.

Designed for DC-biased operation, it exhibits reverse leakage ≤1 μA at VR = 15 V and maintains zener impedance ≤100 Ω across 0.5–1 mA operating range - enabling stable regulation even under light-load or high-impedance source conditions.

Key Specifications

Pinout & Package

Package: DO-35 glass axial lead package (JEITA code GRZZ0002ZB-A), 2.0 mm diameter × 4.2 mm body length, orange body color, navy-blue cathode band. Mass: 0.13 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5242B and BZX55C20, the HZ20-3LTD-E delivers superior noise performance, tighter voltage tolerance, and better temperature coefficient alignment - making it the preferred choice for precision analog reference paths where signal integrity is paramount.

Availability

HZ20-3LTD-E is available at Aetrix Electronics and suitable for industrial power supplies, precision sensor interfaces, audio equipment, and test instrumentation requiring stable component supply with consistent parametric performance across production lots.

Supply support for HZ20-3LTD-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 applications.

The HZ-L Series was developed specifically for low-noise, high-stability voltage reference applications in analog signal chains - targeting designers of precision measurement, audio, and industrial control systems.

FAQ

What is the zener voltage range of the HZ20-3LTD-E?

The HZ20-3LTD-E has a specified zener voltage range of 20.2 V to 21.1 V when tested at 0.5 mA zener current and 25°C ambient temperature. This tight 0.9 V window ensures consistent reference accuracy across production units and simplifies tolerance budgeting in feedback networks. The HZ20-3LTD-E achieves this via controlled diffusion and annealing processes unique to the HZ-L Series.

Does the HZ20-3LTD-E support high-frequency noise suppression?

The HZ20-3LTD-E is engineered for low broadband noise - approximately 1/3 to 1/10 that of the legacy HZ series - due to optimized junction geometry and surface passivation. While not a filtering component per se, its intrinsic low-noise behavior directly improves SNR in sensitive analog stages like microphone preamps or precision ADC references. The HZ20-3LTD-E does not incorporate external capacitors or EMI shielding.

Can the HZ20-3LTD-E be used in place of a TL431 shunt regulator?

The HZ20-3LTD-E cannot replace a TL431 directly because it lacks active error amplification, adjustable output, or current-sinking capability. However, in fixed-voltage, low-current reference roles (e.g., op-amp biasing or ADC reference), the HZ20-3LTD-E offers lower noise and simpler implementation than a TL431-based circuit. Use the HZ20-3LTD-E where passive simplicity and noise performance outweigh programmability needs.

What is the maximum allowable power dissipation for the HZ20-3LTD-E at 70°C ambient?

At 70°C ambient temperature, the HZ20-3LTD-E's power dissipation must be derated linearly from its 400 mW rating at 25°C. Using the thermal resistance implied by the "Power Dissipation vs. Ambient Temperature" curve on page 4 of REJ03G0182-0300, the maximum allowable P_d is approximately 280 mW. Exceeding this risks junction temperature exceeding 175°C and accelerated parameter drift. Always verify with actual board layout thermal performance.

Is the HZ20-3LTD-E RoHS compliant and halogen-free?

Yes, the HZ20-3LTD-E complies with EU RoHS Directive 2011/65/EU and is halogen-free per Renesas' material declarations. The DO-35 glass package contains no lead in solderable terminations, and all die attach, passivation, and molding compounds meet restricted substance thresholds. Full compliance documentation is available via Renesas' environmental portal referenced in REJ03G0182-0300.