Renesas RD33F-T6-AZ

Overview

RD33F-T6-AZ from Renesas Electronics is a 1 W planar-type silicon Zener diode with nominal zener voltage of 33 V (B3 grade: 32.39–34.15 V), dynamic impedance ≤18 Ω at 10 mA, and reverse current ≤10 μA at 25 V. It features a DO-41 glass-sealed DHD package, −65 to +175 °C storage temperature range, and is used for precision voltage regulation and surge absorption in industrial power supplies.

For engineers reviewing the RD33F-T6-AZ datasheet, RD33F-T6-AZ pinout, RD33F-T6-AZ application, or RD33F-T6-AZ equivalent, key selection criteria include zener voltage tolerance (±2.7% B3 grade), thermal resistance (150 °C/W typical), junction temperature limit (175 °C), and surge reverse power rating (400 W at 10 μs).

Technical Context

This device operates as a two-terminal voltage reference using avalanche breakdown in a planar-diffused silicon junction. Its zener voltage temperature coefficient is +25 mV/°C (typical), indicating positive drift above ~5 V, and it maintains stable regulation under DC and transient reverse-biased conditions up to its 1 W steady-state dissipation limit.

The DO-41 package provides axial lead mounting with black cathode band marking, and thermal performance depends on PCB copper area per Figure 2 - minimum 5 mm² foil required for full 1 W rating at TA = 25 °C. Surge capability is defined for non-repetitive 10 μs pulses only.

Key Specifications

Pinout & Package

RD33F-T6-AZ uses a DO-41 axial-leaded glass package (JEDEC standard) with cathode indicated by a black band. Leads are tinned copper-clad steel; body diameter 3.0 mm max, length 5.0 mm max, lead spacing 25 mm min.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4747A and BZX85C33, RD33F-T6-AZ offers tighter voltage tolerance (±2.7% vs. ±5%), lower dynamic impedance (≤18 Ω vs. ≥20 Ω), and lower leakage (≤10 μA vs. ≥50 μA), making it preferable for high-stability reference and low-drift sensing applications.

Availability

RD33F-T6-AZ is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, and precision reference designs requiring stable component supply and long-lifecycle support.

Supply support for RD33F-T6-AZ 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 manufacturer headquartered in Japan, specializing in microcontrollers, analog and power devices, and system-on-chip solutions for industrial, automotive, and infrastructure markets.

RD33F-T6-AZ belongs to the RD2.0F–RD82F planar zener diode family designed for reliable voltage regulation and transient suppression in standard-grade industrial equipment, with emphasis on thermal robustness and E24-compliant voltage standardization.

FAQ

What is the exact zener voltage range for RD33F-T6-AZ?

The RD33F-T6-AZ has a guaranteed zener voltage range of 32.39 V to 34.15 V at test current I_Z = 10 mA, corresponding to the B3 grade per Renesas datasheet D13936EJ5V0DS. This ±2.7% tolerance is tighter than standard B-grade (±5%) and enables higher-accuracy voltage referencing in critical circuits where RD33F-T6-AZ is deployed.

Does RD33F-T6-AZ have a specified junction-to-case thermal resistance?

No - the RD33F-T6-AZ datasheet does not specify R_θJC. Instead, it provides ambient-based derating curves (Figure 1) and transient thermal impedance data (Figure 8), with a typical R_θJA of 150 °C/W for minimal PCB copper (5 mm²). Designers must use these ambient-referenced metrics rather than junction-to-case values when calculating safe operating area for RD33F-T6-AZ.

Can RD33F-T6-AZ be used in automotive applications?

RD33F-T6-AZ is rated as "Standard" quality grade per Renesas documentation, intended for computers, office equipment, and industrial robots - not automotive systems. It lacks AEC-Q200 qualification, extended temperature validation beyond −65 to +175 °C, or automotive-specific reliability testing. For automotive use, a qualified alternative such as the MMBZ5248BLT1G must be selected instead of RD33F-T6-AZ.

What is the surge reverse power rating of RD33F-T6-AZ and how is it applied?

RD33F-T6-AZ has a non-repetitive surge reverse power rating of 400 W at pulse width t = 10 μs (Figure 7). This rating applies only to single, isolated transients - not repetitive events - and assumes T_A = 25 °C. Engineers must ensure inter-pulse intervals allow full thermal recovery; exceeding this limit risks irreversible junction damage in RD33F-T6-AZ.

How does the zener voltage temperature coefficient of RD33F-T6-AZ affect circuit performance?

RD33F-T6-AZ exhibits a typical zener voltage temperature coefficient (γ_Z) of +25 mV/°C, meaning its regulated voltage increases ~0.076% per °C rise. In a 33 V reference, this yields ~+830 mV drift over a 33 °C ambient change. Designers compensate by pairing RD33F-T6-AZ with negative-TC components or calibrating out drift in systems where RD33F-T6-AZ serves as primary reference.