Renesas RKZ12B2KJ#R1

Overview

RKZ12B2KJ#R1 from Renesas Electronics is a silicon planar Zener diode designed for precision voltage stabilization and transient surge absorption in low-power signal paths. It delivers a nominal Zener voltage of 12.0 V (11.74–12.24 V), 2 μA maximum reverse leakage at 9.0 V, 35 Ω dynamic resistance at 5 mA, and 150 mW power dissipation on PCB - used in voltage reference circuits for sensor signal conditioning and I/O protection in industrial microcontroller interfaces.

For engineers reviewing the RKZ12B2KJ#R1 datasheet, RKZ12B2KJ#R1 pinout, RKZ12B2KJ#R1 application, or RKZ12B2KJ#R1 equivalent, key selection criteria include its UFP (SC-79) surface-mount package, ESD robustness (±30 kV per IEC 61000-4-2), tight 12 V Zener tolerance, and suitability for space-constrained 3.3 V/5 V rail clamping and analog front-end biasing.

Technical Context

This device operates as a two-terminal, cathode-anode configured Zener diode with a planar junction structure optimized for stable breakdown behavior under DC and low-energy transients. Its temperature coefficient is approximately +0.04 %/°C near 12 V, indicating positive drift with rising junction temperature.

The RKZ12B2KJ#R1 is rated for nonrepetitive surge reverse power up to ~1.2 W for 1 ms pulses and maintains ≤2 μA reverse current below 9.0 V - enabling reliable operation in low-quiescent-current voltage monitoring and overvoltage clamp applications without significant standby loading.

Key Specifications

Pinout & Package

Package: Ultra Small Flat Lead (UFP), JEITA code SC-79, Renesas code PWSF0002ZA-A - 1.7 mm × 1.2 mm × 0.6 mm footprint ideal for high-density PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84-C12LT1G and MMSZ4689T1G, the RKZ12B2KJ#R1 offers superior board-area efficiency (1.7 mm × 1.2 mm), tighter voltage tolerance (±2.1% vs. ±5%), and identical ESD robustness - making it optimal for miniaturized, precision-stabilized 12 V nodes where thermal and spatial constraints dominate.

Availability

RKZ12B2KJ#R1 is available at Aetrix Electronics and suitable for industrial sensor interfaces, microcontroller I/O protection, and low-power battery monitor reference circuits requiring stable component supply and long-term obsolescence management.

Supply support for RKZ12B2KJ#R1 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 delivering microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.

The RKZ-KJ Series is part of Renesas' discrete protection portfolio, engineered specifically for high-precision voltage stabilization and low-energy surge suppression in space-constrained, low-power electronic systems.

FAQ

What is the Zener voltage tolerance of RKZ12B2KJ#R1?

The RKZ12B2KJ#R1 has a Zener voltage range of 11.74 V to 12.24 V at 5 mA test current, corresponding to a ±2.1% tolerance around the nominal 12.0 V value. This tight specification is confirmed in the Electrical Characteristics table of the REJ03G1588-0100 datasheet and enables use in applications requiring high-voltage-reference accuracy without external trimming. The RKZ12B2KJ#R1 achieves this via process-controlled planar junction doping and screening.

Does RKZ12B2KJ#R1 support automated SMT assembly?

Yes, RKZ12B2KJ#R1 is supplied in emboss taping reel format compatible with standard pick-and-place machines. Its UFP (SC-79) package features flat leads and symmetrical geometry, ensuring reliable feeding, accurate placement, and zero tombstoning risk during reflow. The laser-marked "12·" identification on the cathode side further aids optical recognition in automated vision systems - all verified in the Ordering Information and Pin Arrangement sections of the official Renesas datasheet for RKZ12B2KJ#R1.

What is the maximum reverse leakage current for RKZ12B2KJ#R1?

The maximum reverse leakage current (I_R) for RKZ12B2KJ#R1 is 2 μA at a reverse voltage (V_R) of 9.0 V, as specified in the Electrical Characteristics table. This low leakage ensures minimal loading on high-impedance bias networks and preserves battery life in always-on monitoring circuits. The RKZ12B2KJ#R1 maintains this performance across its full operating temperature range (−55°C to +150°C), with no degradation observed in accelerated life testing.

Can RKZ12B2KJ#R1 be used for ESD protection on USB data lines?

No - RKZ12B2KJ#R1 is not recommended for USB data line (D+/D−) protection due to its 12 V breakdown voltage and lack of differential-mode or low-capacitance optimization. It is designed for single-ended, higher-voltage clamping (e.g., VBUS, power rails, analog references). For USB data lines, dedicated low-capacitance ESD arrays or TVS diodes with sub-1 V clamping and <1.5 pF capacitance are required. The RKZ12B2KJ#R1's ±30 kV HBM rating applies only to single-pin-to-ground stress, not high-speed differential signaling integrity.

What is the thermal resistance (R_θJA) of RKZ12B2KJ#R1?

The datasheet does not specify junction-to-ambient thermal resistance (R_θJA) for RKZ12B2KJ#R1 as an absolute value; instead, it provides the derating curve in Figure 3 (Power Dissipation vs. Ambient Temperature), showing 150 mW maximum at T_A = 25°C and linear reduction to zero at 150°C. Based on this curve and UFP package geometry, typical R_θJA is estimated at ~670°C/W on standard FR-4 with minimal copper pour - consistent with other SC-79 Zeners. This value is critical when calculating safe operating temperature for RKZ12B2KJ#R1 in thermally isolated layouts.