Renesas HZU18B1TRF-E

Overview

HZU18B1TRF-E from Renesas Electronics is a silicon planar Zener diode designed for precision voltage stabilization in low-power analog and reference circuits, featuring a nominal Zener voltage of 18.5 V (min 18.86 V, max 19.70 V at 5 mA), 200 mW power dissipation, and ultra-small URP (SC-76A) surface-mount package. It serves as a stable shunt reference in power supply feedback loops, sensor biasing networks, and overvoltage protection clamps.

For engineers reviewing the HZU18B1TRF-E datasheet, HZU18B1TRF-E pinout, HZU18B1TRF-E application, or HZU18B1TRF-E equivalent, key selection criteria include Zener voltage tolerance (±2.8% at 18.5 V), dynamic resistance (45 Ω at 5 mA), reverse leakage (<2 μA at 14.4 V), junction temperature limit (150°C), and tape-and-reel packaging (3,000 pcs/reel) for automated SMT assembly.

Technical Context

The HZU18B1TRF-E operates as a two-terminal shunt regulator, maintaining a stable output voltage across its cathode-anode terminals when reverse-biased above its specified Zener breakdown threshold. Its silicon planar construction ensures consistent breakdown characteristics and low temperature coefficient (≈+0.04 %/°C near 18 V).

Designed for DC voltage reference and clamping, it requires a series current-limiting resistor to set operating current between 2 mA and 5 mA - within which its dynamic resistance remains ≤45 Ω and voltage regulation is optimized. The device exhibits no switching or control logic; functionality is purely passive and voltage-defined.

Key Specifications

Pinout & Package

Ultra-small Resin Package (URP, JEITA code SC-76A) with 2-pin surface-mount configuration; dimensions 0.8 mm × 1.25 mm × 0.55 mm (L × W × H), weight 0.004 g, compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C18LT1G and MMSZ5246B-TP, the HZU18B1TRF-E delivers tighter voltage tolerance (±2.8% vs. ±5%), smaller URP footprint (0.8 × 1.25 mm vs. ≥2.7 × 1.6 mm), and optimized dynamic resistance for precision regulation - making it preferred for space-constrained, high-accuracy reference designs where 200 mW suffices.

Availability

HZU18B1TRF-E is available at Aetrix Electronics and suitable for industrial sensor interfaces, compact power supply feedback loops, and embedded overvoltage protection circuits requiring stable component supply, consistent Zener voltage grading, and RoHS-compliant SMT packaging.

Supply support for HZU18B1TRF-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 mixed-signal devices, and power management ICs for industrial, automotive, and infrastructure applications.

The HZU Series belongs to Renesas' discrete Zener diode product line, engineered specifically for high-stability voltage reference and clamping in space-constrained, low-power systems - emphasizing tight grading, low dynamic resistance, and ultra-miniature packaging.

FAQ

What is the Zener voltage range of the HZU18B1TRF-E at 5 mA test current?

The HZU18B1TRF-E has a guaranteed Zener voltage range of 18.86 V (minimum) to 19.70 V (maximum) when tested at I_Z = 5 mA, corresponding to Grade B1 specification per Renesas datasheet R07DS0423EJ1000. This 4.5% total spread ensures predictable regulation behavior in precision reference applications where tighter tolerance than standard Zeners is required.

Does the HZU18B1TRF-E require a heatsink in typical operation?

No, the HZU18B1TRF-E does not require a heatsink under normal operating conditions. With a maximum power dissipation of 200 mW at 25°C ambient and a thermal resistance (junction-to-ambient) typical of ~650°C/W for the URP package, self-heating remains within safe limits when operated ≤5 mA. Derating begins above 70°C ambient per Fig.3 in the datasheet, but PCB copper area alone suffices for thermal management in most applications.

What is the reverse leakage current specification for HZU18B1TRF-E at 14.4 V?

The reverse leakage current (I_R) for HZU18B1TRF-E is specified as ≤2 μA at V_R = 14.4 V (80% of nominal Zener voltage), measured at T_a = 25°C. This low leakage ensures minimal error contribution in high-impedance reference nodes and preserves accuracy in battery-powered or low-quiescent-current designs where standby current matters.

Is the HZU18B1TRF-E compatible with lead-free reflow soldering processes?

Yes, the HZU18B1TRF-E is qualified for lead-free reflow soldering per J-STD-020. Its URP package and internal construction meet RoHS requirements and withstand peak reflow temperatures up to 260°C (10-second duration). The device is supplied in TRF taping (3,000 pcs/reel) compatible with standard SMT placement equipment and IPC-A-610 Class 2/3 assembly standards.

How does the dynamic resistance of HZU18B1TRF-E affect voltage regulation stability?

The dynamic resistance (r_d) of HZU18B1TRF-E is ≤45 Ω at I_Z = 5 mA, directly determining how much the Zener voltage shifts with changes in current. For example, a ±1 mA current variation causes ≤±45 mV output shift - enabling stable regulation in feedback loops where load or input variations are moderate. Lower r_d than generic Zeners improves line/load regulation by reducing sensitivity to current fluctuations.