Renesas HZS12A2TD-E

Overview

HZS12A2TD-E from Renesas Electronics is a silicon planar Zener diode designed for precision voltage regulation in low-power stabilized power supplies. It delivers a nominal zener voltage of 12.2 V (min 11.9 V, max 12.4 V) at 5 mA test current, with dynamic resistance of 9.5 Ω, maximum power dissipation of 400 mW, and operates within −55°C to +175°C storage temperature range - used in voltage reference and overvoltage protection circuits for industrial control modules.

For engineers reviewing the HZS12A2TD-E datasheet, HZS12A2TD-E pinout, HZS12A2TD-E application, or HZS12A2TD-E equivalent, key selection criteria include its 12.2 V zener voltage tolerance, low 9.5 Ω dynamic impedance, 400 mW power rating, MHD package compatibility with 5 mm-pitch automatic insertion, and suitability for space-constrained board-level voltage stabilization.

Technical Context

This device employs a silicon planar junction structure optimized for stable reverse-breakdown behavior under DC bias. Its zener voltage is specified at 5 mA test current with ±0.5 V tolerance across grade A2, and exhibits a negative temperature coefficient typical of mid-voltage Zeners (~−0.04 %/°C per Fig.2).

The HZS12A2TD-E is rated for 200°C junction temperature and supports operation up to 175°C ambient storage. Its low leakage current (<5 µA at VR = 10.2 V) and tight VZ distribution make it suitable for calibration references and feedback-sense nodes in linear regulators.

Key Specifications

Pinout & Package

Package: MHD (JEITA code GRZZ0002ZC-A), molded plastic, 2-pin axial lead, 2.0 mm diameter × 26.0 mm length, 5 mm pitch compatible, mass ≈ 0.084 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C12LT1G and 1N4742A, the HZS12A2TD-E offers tighter V_Z tolerance (±0.5 V vs. ±0.6 V and ±0.6 V), lower r_d (9.5 Ω vs. 25 Ω and 22 Ω), and MHD packaging optimized for high-volume through-hole assembly - making it preferable for cost-sensitive, precision-stable 12 V reference designs.

Availability

HZS12A2TD-E is available at Aetrix Electronics and suitable for industrial control systems, programmable logic controllers (PLCs), medical diagnostic equipment, and test & measurement instruments requiring stable component supply and long-term obsolescence management.

Supply support for HZS12A2TD-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 infrastructure markets.

The HZS Series is part of Renesas' discrete diode portfolio, engineered specifically for high-reliability voltage stabilization in industrial-grade power management and protection circuits - emphasizing tight parametric control, thermal robustness, and automated manufacturing compatibility.

FAQ

What is the exact zener voltage range for HZS12A2TD-E at 5 mA test current?

The HZS12A2TD-E has a guaranteed zener voltage range of 11.9 V minimum to 12.4 V maximum when tested at I_Z = 5 mA and T_a = 25°C. This 0.5 V span reflects Grade A2 specification per Renesas REJ03G0184-0500 Rev.5.00, and is tighter than standard Zener grades - critical for applications requiring predictable clamping thresholds. The HZS12A2TD-E maintains this specification across its qualified temperature range.

Is HZS12A2TD-E suitable for surface-mount assembly?

No, the HZS12A2TD-E uses the MHD axial-leaded package (JEITA code GRZZ0002ZC-A), designed explicitly for through-hole mounting and 5 mm-pitch high-speed automatic insertion. It is not a surface-mount device. For SMT alternatives, consider the BZX84-C12LT1G - but note that HZS12A2TD-E's electrical performance (9.5 Ω r_d, tighter V_Z) cannot be directly replicated in SOT-23 form without trade-offs in regulation precision and thermal handling.

What is the maximum allowable reverse voltage before breakdown for HZS12A2TD-E?

The HZS12A2TD-E is rated for ≤5 µA reverse leakage current at V_R = 10.2 V, meaning it remains effectively non-conductive below its nominal zener voltage. Breakdown begins near 11.9 V and stabilizes fully by 12.4 V at 5 mA. Applying >12.4 V continuously without current limiting will exceed its 400 mW power rating and risk thermal failure. Always use a series current-limiting resistor sized for worst-case input voltage and load conditions when using HZS12A2TD-E.

Does HZS12A2TD-E meet RoHS requirements?

Yes, HZS12A2TD-E complies with the EU RoHS Directive, as confirmed by Renesas Electronics' environmental compliance documentation. The device contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE) above threshold limits. Full material declarations and substance reports are available via Renesas' official product page and environmental portal.

Can HZS12A2TD-E replace 1N4742A in existing designs?

Direct replacement is not recommended without validation. While both regulate near 12 V, the HZS12A2TD-E has tighter V_Z tolerance (±0.5 V vs. ±0.6 V), lower dynamic resistance (9.5 Ω vs. 22 Ω), and different package (MHD vs. DO-41). Mechanical fit, thermal dissipation paths, and PCB hole pattern differ significantly. The HZS12A2TD-E may improve regulation accuracy but requires layout verification and thermal assessment - especially given its 400 mW vs. 1 W rating.