Renesas RD30F

Overview

RD30F from Renesas Electronics is a 1 W planar-type silicon Zener diode in DO-41 glass-sealed DHD package, with nominal zener voltage 30 V (B grade: 27.43–31.26 V), dynamic impedance ≤18 Ω at 10 mA, and temperature coefficient +23 mV/°C (typical). It serves as a precision voltage reference and overvoltage clamp in power supply regulation and surge protection circuits.

For engineers reviewing the RD30F datasheet, RD30F pinout, RD30F application, or RD30F equivalent, this page delivers verified electrical specs, thermal derating curves, JEDEC DO-41 mechanical data, and direct alternatives for voltage reference and transient suppression design-in.

Technical Context

The RD30F operates as a two-terminal voltage-regulating device relying on reverse-biased avalanche breakdown. Its planar junction structure ensures stable zener voltage tolerance and low dynamic impedance across its rated current range of 10 mA.

It features a glass-passivated DO-41 package with cathode marking (black band), rated for 175°C maximum junction temperature and capable of absorbing 400 W surge reverse power for 10 μs pulses per Figure 7 of D13936EJ5V0DS.

Key Specifications

Pinout & Package

RD30F uses the JEDEC-standard DO-41 axial-leaded glass package (3.0 mm diameter × 5.0 mm max length), with cathode identified by a black band. No internal terminals-device functions as a two-terminal passive component.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RD30F, the 1N5256B and BZX55-C30 offer lower-cost alternatives at reduced power and surge capability; RD30F remains optimal where 1 W continuous regulation, 400 W transient absorption, and DO-41 mechanical robustness are required.

Availability

RD30F is available at Aetrix Electronics and suitable for industrial power supplies, sensor reference circuits, and surge-protected communication interfaces requiring stable component supply and long-term obsolescence management.

Supply support for RD30F 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 formed in 2010 via merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, and discrete power components.

The RD30F belongs to the RD2.0F–RD82F planar zener diode family designed for general-purpose voltage regulation and transient suppression in standard-grade industrial and commercial equipment.

FAQ

What is the zener voltage tolerance of RD30F at 10 mA test current?

The RD30F has a B-grade zener voltage range of 27.43 V to 31.26 V when measured at I_Z = 10 mA and 40 ms after power-on, per datasheet D13936EJ5V0DS. This ±6.4% tolerance reflects the E24-series standardization and enables interchangeability within that voltage band. RD30F's specified min/max values are confirmed in Table 4 on page 4 of the document.

Does RD30F support surge protection per ISO 7637-2 Pulse 1?

Yes, RD30F supports ISO 7637-2 Pulse 1 (inductive load dump) due to its 400 W surge reverse power rating at t = 10 μs (Figure 7, D13936EJ5V0DS). When used with appropriate series impedance, RD30F clamps transients to ≤31.3 V, protecting downstream 3.3 V or 5 V logic. Its DO-41 package provides sufficient thermal mass for single-event dissipation without derating.

What is the thermal resistance and derating behavior of RD30F?

RD30F exhibits a typical thermal resistance of ~150°C/W (Figure 8, D13936EJ5V0DS) and follows the P vs. T_A curve in Figure 1: full 1.0 W at 25°C, linearly derating to zero at 175°C ambient. For PCB layout, ≥20 mm² copper pour reduces R_th significantly; RD30F's DO-41 leads allow direct soldering to thermal pads without vias.

How does the temperature coefficient of RD30F affect long-term voltage stability?

RD30F has a typical zener voltage temperature coefficient of +23 mV/°C (page 4, D13936EJ5V0DS), meaning its regulated voltage increases by ~0.077% per °C rise. In a 0–70°C ambient range, this yields ~1.6 V total drift. For precision references, this must be compensated in firmware or paired with a negative-TC component; RD30F is intended for applications where ±3% regulation is acceptable.

Is RD30F RoHS compliant and lead-free?

Yes, RD30F complies with EU RoHS Directive requirements as confirmed by Renesas Electronics' environmental documentation. The device uses lead-free glass encapsulation and matte tin-plated leads. Full compliance status, including substance declarations and exemption details, is available through Renesas' official product page and material disclosure reports for RD30F.