Renesas HZU3.9B2TRF-E

Overview

HZU3.9B2TRF-E from Renesas Electronics is a silicon planar Zener diode designed for precision voltage stabilization in low-power analog and digital supply rails, featuring a nominal Zener voltage of 3.9 V (min 3.87 V, max 4.10 V) at 5 mA, 200 mW power dissipation, and 130 Ω dynamic resistance - deployed in ultra-small surface-mount URP (SC-76A) packages for space-constrained power management circuits.

For engineers reviewing the HZU3.9B2TRF-E datasheet, HZU3.9B2TRF-E pinout, HZU3.9B2TRF-E application, or HZU3.9B2TRF-E equivalent, key selection considerations include its B2-grade voltage tolerance (±2.8%), low leakage (<10 µA at 1.0 V), thermal coefficient behavior near zero crossing (~0 mV/°C), and suitability for reference voltage generation in portable instrumentation and sensor biasing networks.

Technical Context

The HZU3.9B2TRF-E operates as a two-terminal shunt regulator with fixed breakdown voltage defined by controlled doping and planar junction geometry. Its Zener mechanism dominates conduction above 3.87 V, with stable regulation maintained across 0–5 mA test current range and ambient temperatures from –55°C to +150°C.

Thermal derating follows a linear 200 mW maximum at 25°C, decreasing to zero at 150°C junction temperature per Fig.3. The device exhibits minimal voltage drift near 3.9 V due to balanced Zener and avalanche contributions, reflected in its near-zero temperature coefficient (≈0 mV/°C) per Fig.2.

Key Specifications

Pinout & Package

URP (Ultra Small Resin Package, JEITA code SC-76A) is a surface-mount, two-terminal plastic package with 0.8 mm × 0.8 mm body size, 0.45 mm height, and gull-wing leads optimized for automated placement and IR reflow. Cathode marked with band on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C3V9 and MMSZ4685, the HZU3.9B2TRF-E delivers superior voltage accuracy (±2.8% vs. ±5%), lower dynamic impedance (130 Ω vs. ≥150 Ω), and smallest footprint (0.8 mm² vs. ≥1.0 mm²), making it optimal for next-generation space- and precision-constrained applications.

Availability

HZU3.9B2TRF-E is available at Aetrix Electronics and suitable for portable sensor biasing, microcontroller reset reference, and USB-C power negotiation requiring stable component supply with consistent Zener voltage grading and tape-and-reel delivery (3,000 pcs/reel).

Supply support for HZU3.9B2TRF-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 leader specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.

The HZU Series belongs to Renesas' precision discrete portfolio, engineered specifically for high-stability voltage reference and shunt regulation in compact, thermally constrained systems.

FAQ

What is the Zener voltage tolerance for HZU3.9B2TRF-E?

The HZU3.9B2TRF-E has a B2-grade Zener voltage specification of 3.87 V to 4.10 V at 5 mA test current, corresponding to ±2.8% tolerance around the nominal 3.9 V value. This tighter tolerance than standard B-grade devices enables improved accuracy in reference-sensitive circuits without external trimming. The HZU3.9B2TRF-E achieves this via controlled diffusion and laser adjustment during manufacturing.

Does HZU3.9B2TRF-E support operation at elevated temperatures?

Yes, the HZU3.9B2TRF-E is rated for junction temperatures from –55°C to +150°C and storage temperatures over the same range. Its power dissipation derates linearly from 200 mW at 25°C to zero at 150°C, as shown in Fig.3 of the datasheet. This makes the HZU3.9B2TRF-E suitable for under-hood automotive modules and industrial motor drives where ambient temperatures exceed 85°C.

What is the package type and dimensions of HZU3.9B2TRF-E?

The HZU3.9B2TRF-E uses the URP (Ultra Small Resin Package), also known as SC-76A per JEITA, with nominal dimensions of 0.8 mm × 0.8 mm × 0.45 mm. It features gull-wing leads and a cathode band marking. This package is optimized for high-density SMT assembly and compatible with standard 0402 reflow profiles, enabling direct replacement of larger SOD-323 or SOT-23 Zeners where board space is critical.

How does the dynamic resistance of HZU3.9B2TRF-E affect its regulation performance?

The HZU3.9B2TRF-E specifies a maximum dynamic resistance (r_d) of 130 Ω at 5 mA, which directly determines how much the output voltage varies with load current changes. Lower r_d yields tighter regulation - for example, a 1 mA load shift causes only ~0.13 V deviation. This performance supports stable reference generation in ADC buffers and op-amp bias networks where low noise and minimal drift are essential. The HZU3.9B2TRF-E achieves this via optimized planar junction design.

Is HZU3.9B2TRF-E RoHS compliant and halogen-free?

Yes, the HZU3.9B2TRF-E complies with EU RoHS Directive 2011/65/EU and is halogen-free per Renesas' material declarations. The device uses lead-free matte tin plating on terminals and environmentally compliant molding compound. Full compliance documentation, including substance declarations and test reports, is available through Renesas' official portal and authorized distributors. The HZU3.9B2TRF-E meets AEC-Q200 stress test requirements for passive components in automotive applications.