Renesas RKZ5.1BKU#P6

Overview

RKZ5.1BKU#P6 from Renesas Electronics is a silicon planar Zener diode designed for precision voltage regulation in low-power analog and digital circuits, with a nominal Zener voltage of 5.1 V, ±5% tolerance (4.84–5.37 V), 700 mW power dissipation, and dynamic resistance of 130 Ω at 10 mA test current - deployed in compact SRP-F surface-mount packages for voltage reference and overvoltage protection in power supply rails.

For engineers reviewing the RKZ5.1BKU#P6 datasheet, RKZ5.1BKU#P6 pinout, RKZ5.1BKU#P6 application, or RKZ5.1BKU#P6 equivalent, this device serves as a stable, low-noise, ESD-hardened (±30 kV HBM) voltage clamp for microcontroller I/O protection, sensor biasing, and feedback loop referencing where thermal stability and small-footprint SMT integration are critical.

Technical Context

This Zener diode operates in reverse breakdown mode to maintain a stable reference voltage across its terminals under varying load and temperature conditions. Its design centers on tight voltage tolerance (±5%), low dynamic impedance (130 Ω), and high ESD robustness (30 kV per HBM), enabling reliable clamping in noise-sensitive signal conditioning paths.

The device uses a silicon planar junction structure fabricated for consistent breakdown characteristics and low leakage. It is rated for 150°C maximum junction temperature and derates linearly above 25°C ambient, with power dissipation limited to 700 mW on a standard 50 × 50 mm glass-epoxy PCB with 10 × 10 mm solder land.

Key Specifications

Pinout & Package

SRP-F is a 2-pin surface-mount flat-lead package with exposed cathode and anode terminals on opposite ends. The package features a small footprint (3.3 mm × 1.6 mm) and low profile (1.2 mm height), optimized for space-constrained applications requiring high thermal efficiency and mechanical reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C5V1,115 and MMSZ5231B-TP, RKZ5.1BKU#P6 delivers superior thermal capability (700 mW), lower dynamic impedance (130 Ω), and industry-leading ESD immunity (±30 kV), making it optimal for high-reliability, space-constrained voltage reference and protection roles where long-term stability and transient resilience are mandatory.

Availability

RKZ5.1BKU#P6 is available at Aetrix Electronics and suitable for industrial sensor interfaces, embedded power management subsystems, and automotive body electronics requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for RKZ5.1BKU#P6 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 timing solutions for industrial, automotive, and infrastructure markets.

The RKZ-KV Series is part of Renesas' precision discrete portfolio, engineered specifically for stable voltage regulation and transient suppression in compact, high-density SMT designs where thermal performance and ESD hardness are essential.

FAQ

What is the Zener voltage tolerance of RKZ5.1BKU#P6?

The RKZ5.1BKU#P6 has a Zener voltage range of 4.84 V to 5.37 V at 10 mA test current, corresponding to a ±5% tolerance around the nominal 5.1 V rating. This tight tolerance ensures predictable regulation behavior in feedback loops and reference circuits without requiring post-production trimming or calibration.

Does RKZ5.1BKU#P6 support automatic optical inspection (AOI) after reflow?

Yes, RKZ5.1BKU#P6 features a laser-marked "5·1" identifier on the SRP-F package surface, compatible with standard AOI systems. The flat-lead geometry and consistent marking contrast enable reliable detection and verification during post-reflow inspection in high-volume manufacturing lines.

Can RKZ5.1BKU#P6 be used in place of a 5 V LDO for low-current biasing?

RKZ5.1BKU#P6 is not a replacement for an LDO regulator but serves as a passive voltage reference or clamp. It lacks current-limiting or regulation circuitry, so it must be used with a series current-limiting resistor. For biasing low-current sensors (<1 mA), RKZ5.1BKU#P6 offers lower quiescent current and smaller footprint than most 5 V LDOs, provided load stability requirements align with its ±5% tolerance.

What is the thermal resistance (R_θJA) of RKZ5.1BKU#P6 on a standard PCB?

Renesas specifies RKZ5.1BKU#P6's power derating based on ambient temperature using a 50 × 50 mm glass-epoxy board with 10 × 10 mm copper land. While R_θJA is not explicitly published, the 700 mW rating at 25°C and linear derating to zero at 150°C implies an effective R_θJA ≈ 179 °C/W under those exact board conditions - critical for thermal margin analysis in sealed enclosures.

Is RKZ5.1BKU#P6 RoHS compliant and halogen-free?

Yes, RKZ5.1BKU#P6 complies with EU RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. Renesas confirms full compliance in its product change notifications and material declarations, supporting environmentally regulated industrial and consumer electronics programs.