Renesas HZK9B-JTR

Overview

HZK9B-JTR from Renesas Electronics is a silicon epitaxial planar Zener diode designed for voltage regulation and stabilization in low-power supply circuits. It delivers a nominal zener voltage of 8.3–9.1 V at 5 mA, with dynamic resistance ≤20 Ω, maximum power dissipation of 500 mW, and operates within a junction temperature range of –55°C to +175°C. It is commonly used in precision reference circuits and overvoltage protection stages of consumer-grade power supplies.

For engineers reviewing the HZK9B-JTR datasheet, HZK9B-JTR pinout, HZK9B-JTR application, or HZK9B-JTR equivalent, key selection criteria include its 8.3–9.1 V zener voltage tolerance, 20 Ω dynamic impedance at 5 mA, LLD surface-mount package compatibility, low leakage current (≤1 µA at 0.5 V), and suitability for stabilized DC biasing in analog sensor interfaces and microcontroller reset circuits.

Technical Context

The HZK9B-JTR functions as a two-terminal shunt voltage regulator, maintaining stable output voltage across varying load currents by operating in reverse breakdown. Its silicon epitaxial planar construction ensures tight zener voltage distribution and low temperature coefficient (≈+4.5 mV/°C near 9 V).

It is rated for 500 mW power dissipation on a standard PCB, with thermal derating above 25°C ambient, and exhibits low reverse leakage (≤1 µA at VR = 0.5 V) and fast transient response due to minimal junction capacitance - typical for small-signal Zener diodes in the HZK series.

Key Specifications

Pinout & Package

The HZK9B-JTR uses the LLD (Leadless Low-profile Diode) package: a cylindrical, glass-passivated, axial-lead-replacement SMD device with cathode band marking. Dimensions: φ1.4 ± 0.1 mm × 0.35 mm height; mass ≈ 0.027 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX55C9V1 and MMSZ4685, the HZK9B-JTR offers tighter 8.3–9.1 V (±0.4 V) grading, lower dynamic resistance, and the compact LLD package - making it preferable for space-constrained, high-stability SMT designs where precise low-voltage reference is critical.

Availability

HZK9B-JTR is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, microcontroller reset circuitry, and consumer audio power supply filtering requiring stable component supply and long-term obsolescence management.

Supply support for HZK9B-JTR 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 automotive, industrial, and consumer markets.

The HZK Series was developed as a family of precision silicon Zener diodes targeting cost-sensitive, high-volume stabilized power supply applications in standard-grade electronics - emphasizing reliability, tight voltage grading, and SMT manufacturability.

FAQ

What is the exact zener voltage range specified for HZK9B-JTR?

The HZK9B-JTR has a guaranteed zener voltage range of 8.3 V to 9.1 V when tested at I_Z = 5 mA and T_a = 25°C. This 0.8 V span reflects Grade B tolerance within the HZK9 family and is confirmed in the Renesas HZK Series datasheet Rev.3.00. The HZK9B-JTR achieves this specification using silicon epitaxial planar process control, ensuring consistency across production lots.

Is HZK9B-JTR RoHS compliant?

Yes, the HZK9B-JTR is RoHS compliant per EU Directive 2011/65/EU. Renesas Electronics confirms compliance for all HZK Series devices manufactured after January 2006, and the LLD package contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits. Full material declarations and test reports for HZK9B-JTR are available upon request from Aetrix Electronics.

What is the maximum allowable reverse current before zener conduction begins in HZK9B-JTR?

The HZK9B-JTR specifies a maximum reverse leakage current (I_R) of 1 µA at V_R = 0.5 V and T_a = 25°C. This value is measured well below the knee of the zener curve and confirms minimal parasitic conduction in bias networks. At V_R = 7 V - still below nominal V_Z - leakage remains <10 nA, as inferred from the series' typical I–V characteristics shown in Figure 1 of the HZK datasheet.

Can HZK9B-JTR be used in place of HZK9A-JTR or HZK9C-JTR?

No - HZK9B-JTR is not interchangeable with HZK9A-JTR or HZK9C-JTR without circuit validation. HZK9A-JTR specifies 7.7–8.5 V, HZK9B-JTR 8.3–9.1 V, and HZK9C-JTR 8.9–9.7 V. These non-overlapping ranges reflect distinct grading bins. Substituting across grades risks incorrect biasing or failure to regulate; only same-grade parts (e.g., HZK9B-JTR for HZK9B-JTR) are electrically equivalent.

What is the thermal resistance junction-to-ambient (θ_JA) for HZK9B-JTR in standard mounting?

The HZK9B-JTR does not specify θ_JA explicitly, but its absolute maximum ratings assume 500 mW dissipation on a standard 15 × 20 × 1.6 mm glass-epoxy PCB (Figure 3). Derating begins linearly at 25°C ambient, reaching zero power at ~150°C. Based on thermal modeling of the LLD package and PCB layout, θ_JA is estimated at ≈300°C/W - consistent with similarly sized glass-passivated SMD diodes. For precise thermal design, users should validate with actual board layout and airflow.