Renesas HZM27NBTL

Overview

HZM27NBTL from Renesas Electronics is a silicon epitaxial planar Zener diode designed for precision voltage stabilization in low-power analog and reference circuits. It delivers a nominal zener voltage of 27 V (min 25.1 V, max 28.9 V) at 2 mA test current, with dynamic resistance of 70 Ω, power dissipation rating of 200 mW, and operates within –55°C to +150°C storage temperature range. It is commonly used in overvoltage protection and voltage reference circuits for industrial sensor signal conditioning.

For engineers reviewing the HZM27NBTL datasheet, HZM27NBTL pinout, HZM27NBTL application, or HZM27NBTL equivalent, key selection considerations include its MPAK surface-mount package, 2 mA zener test current, ±1.9 V zener voltage tolerance, 70 Ω dynamic impedance, and suitability for space-constrained DC biasing and regulation where stable 27 V reference is required.

Technical Context

The HZM27NBTL functions as a two-terminal shunt voltage regulator, maintaining a stable reverse-biased breakdown voltage across its cathode–anode terminals. Its silicon epitaxial planar construction ensures tight voltage tolerance and low temperature coefficient (≈+0.045 mV/°C near 27 V), enabling predictable performance across ambient temperatures.

It operates exclusively in reverse breakdown mode with no forward conduction role; the NC (no-connect) pin isolates internal structure and must remain unconnected. Thermal derating follows Fig.3 in the datasheet: power dissipation linearly decreases above 25°C ambient, reaching ~120 mW at 70°C on standard FR-4 PCB.

Key Specifications

Pinout & Package

MPAK package: ultra-thin surface-mount outline with exposed die pad not electrically connected; footprint compatible with SC-59A layout but with distinct terminal geometry per JEITA code PLSP0003ZC-A.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HZM27NBTL, BZX84-C27LT1G offers higher power rating but looser voltage tolerance and higher dynamic impedance, while MMSZ5256ET1G provides superior regulation accuracy and thermal margin at the cost of larger footprint and different test conditions - all three require verification of bias current compatibility in final circuit design.

Availability

HZM27NBTL is available at Aetrix Electronics and suitable for industrial sensor interfaces, PLC input protection circuits, and medical instrumentation reference supplies requiring stable component supply with consistent parametric performance across production lots.

Supply support for HZM27NBTL 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 headquartered in Japan, specializing in microcontrollers, analog power devices, and timing solutions for industrial, automotive, and infrastructure markets.

The HZM-N Series is part of Renesas' discrete Zener diode portfolio, engineered specifically for high-stability voltage reference and overvoltage clamping in space-constrained, thermally demanding applications.

FAQ

What is the zener voltage tolerance of HZM27NBTL at 2 mA test current?

The HZM27NBTL has a zener voltage range of 25.1 V to 28.9 V at I_Z = 2 mA, corresponding to a total tolerance of ±1.9 V around the nominal 27 V rating. This grade-B specification is confirmed in the Electrical Characteristics table on page 2 of R07DS0358EJ0600 Rev.6.00 and applies to all units shipped as HZM27NBTL. The device does not specify tighter binning; full-range tolerance must be accommodated in circuit design.

Can HZM27NBTL be used in place of a 24 V Zener diode for overvoltage protection?

No - HZM27NBTL is rated for 27 V nominal zener voltage and should not substitute for a 24 V device without redesigning the protection threshold. Its minimum specified V_Z is 25.1 V, exceeding typical 24 V system rails; using it would raise clamping voltage by ≥1.1 V, potentially exposing downstream components to unsafe overvoltage. Always match HZM27NBTL to circuits explicitly requiring ~27 V regulation or clamping.

What is the meaning of the 'NC' pin on HZM27NBTL, and must it be left floating?

Pin 1 of HZM27NBTL is designated NC (No Connect) and is internally isolated from the active Zener junction. Per the Pin Arrangement diagram on page 1 of R07DS0358EJ0600 Rev.6.00, this terminal must remain unconnected on the PCB. Routing traces to or soldering to Pin 1 may induce mechanical stress, parasitic capacitance, or unintended current paths that degrade HZM27NBTL's regulation stability or long-term reliability.

Does HZM27NBTL meet RoHS requirements?

Yes - HZM27NBTL complies with the EU RoHS Directive, as confirmed by Renesas Electronics' environmental compliance documentation referenced in the colophon of R07DS0358EJ0600 Rev.6.00. The device contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE) above threshold limits, and is suitable for use in consumer, industrial, and medical electronics subject to RoHS enforcement.

How does ambient temperature affect the power dissipation capability of HZM27NBTL?

HZM27NBTL's power dissipation derates linearly above 25°C ambient, per Fig.3 on page 5 of R07DS0358EJ0600 Rev.6.00. At 70°C ambient, its usable P_d drops to approximately 120 mW on standard FR-4 PCB with 1.6 mm thickness and 1 oz copper. Designers must calculate worst-case junction temperature using θ_JA ≈ 625°C/W (derived from 200 mW / (150°C − 25°C)) and ensure T_j remains ≤150°C under full load and maximum ambient conditions.