Renesas RD36F-T8-AZ

Overview

RD36F-T8-AZ from Renesas Electronics is a 1 W planar-type silicon Zener diode with a nominal zener voltage of 36 V (B3 grade: 35.19–37.01 V), dynamic impedance of 20 Ω at 10 mA, and temperature coefficient of +27 mV/°C. It features DO-41 glass-sealed DHD (Double Heatsink Diode) packaging, operates up to 175°C junction temperature, and is rated for 400 W surge reverse power at 10 μs pulse width. It is used in precision voltage reference and overvoltage protection circuits in industrial power supplies.

For engineers reviewing the RD36F-T8-AZ datasheet, RD36F-T8-AZ pinout, RD36F-T8-AZ application, or RD36F-T8-AZ equivalent, key selection criteria include zener voltage tolerance (±2.7% for B3 grade), thermal resistance (150°C/W transient, ~100°C/W steady-state at 20 mm² copper), low leakage (<10 μA at 28.8 V), and JEDEC DO-41 mechanical compatibility for through-hole PCB mounting.

Technical Context

This Zener diode employs a planar diffusion process on silicon to achieve stable breakdown characteristics and tight voltage distribution across the E24 series. Its DHD structure enhances thermal dissipation via dual heatsinking paths through the axial leads and encapsulated body.

The device exhibits a positive temperature coefficient (+27 mV/°C typical) above ~6 V, enabling predictable drift compensation in reference designs. It supports both DC regulation and transient suppression, with validated surge capability per Figure 7 (400 W, 10 μs) and derated power dissipation down to 0.2 W at 150°C ambient (per Figure 1).

Key Specifications

Pinout & Package

RD36F-T8-AZ uses a standard JEDEC DO-41 axial glass package (3.0 mm diameter × 5.0 mm length), with cathode indicated by a black band. The DHD structure provides dual thermal conduction paths through both leads and body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RD36F-T8-AZ, 1N4738A offers lower voltage and looser tolerance, limiting use in precision references; BZX85C36 matches voltage but has double the dynamic impedance and wider tolerance, degrading regulation accuracy and temperature stability in feedback loops.

Availability

RD36F-T8-AZ is available at Aetrix Electronics and suitable for industrial power supply reference, overvoltage protection circuit, and temperature-compensated sensor bias requiring stable component supply and long-term obsolescence management.

Supply support for RD36F-T8-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 leader headquartered in Japan, specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.

RD36F-T8-AZ belongs to the RD2.0F–RD82F planar Zener diode family, designed specifically for high-reliability voltage regulation and transient suppression in industrial-grade power systems where stable 1 W dissipation and DO-41 mechanical compatibility are essential.

FAQ

What is the exact zener voltage range for RD36F-T8-AZ?

The RD36F-T8-AZ is specified as a B3-grade device with a zener voltage range of 35.19 V to 37.01 V at 10 mA test current, per the official Renesas datasheet D13936EJ5V0DS. This ±2.7% tolerance ensures consistent performance in precision reference applications without requiring binning. The RD36F-T8-AZ achieves this tight distribution using E24-series grading and planar diffusion process control.

Does RD36F-T8-AZ have a positive or negative temperature coefficient?

RD36F-T8-AZ exhibits a positive temperature coefficient of +27 mV/°C typical, as confirmed in Table on page 4 of the Renesas datasheet D13936EJ5V0DS. This behavior is characteristic of Zener diodes above ~6 V and enables predictable voltage drift compensation in temperature-sensitive analog circuits. The RD36F-T8-AZ's coefficient is stable and repeatable across production lots.

What is the maximum surge power rating for RD36F-T8-AZ and under what conditions?

RD36F-T8-AZ is rated for 400 W surge reverse power at a pulse width of 10 μs, as defined in the Absolute Maximum Ratings table and illustrated in Figure 7 of the Renesas datasheet D13936EJ5V0DS. This rating applies at T_A = 25°C and is non-repetitive. The RD36F-T8-AZ leverages its DHD structure to absorb such transients without degradation when properly mounted on adequate copper area.

Is RD36F-T8-AZ compatible with standard DO-41 footprint and assembly processes?

Yes, RD36F-T8-AZ conforms fully to JEDEC DO-41 mechanical specifications: 3.0 mm maximum diameter, 5.0 mm maximum length, and axial lead configuration with cathode marked by a black band. It supports standard wave soldering and hand-soldering profiles. The RD36F-T8-AZ's glass-sealed DHD package meets IPC-J-STD-020 moisture sensitivity level MSL-1, eliminating bake requirements prior to assembly.

What is the thermal resistance profile of RD36F-T8-AZ and how does it affect PCB layout?

RD36F-T8-AZ has a transient thermal impedance of 150°C/W (Figure 8) and steady-state thermal resistance dependent on copper foil area - e.g., ~100°C/W at 20 mm² (Figure 2). For reliable 1 W operation, designers must allocate ≥20 mm² of 1 oz copper connected to both leads. The RD36F-T8-AZ's DHD structure relies on symmetric copper pour to realize its dual heatsink benefit; asymmetric layout increases junction temperature and reduces lifetime.