Renesas RD5.1S-T1-AT

Overview

RD5.1S-T1-AT from Renesas Electronics is a 200 mW, 5.1 V Zener diode in Super Mini Mold (SMD) package, designed for precision voltage regulation and surge suppression in low-power analog circuits. It delivers sharp breakdown at 4.82–5.39 V with dynamic impedance ≤130 Ω at 5 mA, reverse current ≤5 μA at 1.5 V, and operates across –55°C to +150°C junction temperature range. Typical use includes reference voltage generation in sensor signal conditioning and overvoltage clamping in microcontroller I/O protection.

For engineers reviewing the RD5.1S-T1-AT datasheet, RD5.1S-T1-AT pinout, RD5.1S-T1-AT application, or RD5.1S-T1-AT equivalent, this page provides verified electrical specifications, thermal derating behavior, zener voltage tolerance classes (B1/B2/B3), package dimensions, and direct alternative options for voltage reference and transient suppression designs.

Technical Context

This Zener diode operates in reverse-biased breakdown mode with tightly controlled V_Z tolerance per E24 standard and exhibits low dynamic impedance (≤130 Ω) at 5 mA test current, enabling stable regulation under varying load conditions. Its 200 mW power rating is thermally derated above 25°C ambient, following a linear curve down to zero dissipation at 150°C on a standard PCB.

The device features sharp knee characteristics and low leakage (≤5 μA at VR = 1.5 V), making it suitable for low-current biasing and precision threshold detection. Temperature coefficient is not specified individually for RD5.1S-T1-AT but falls within the –0.02 to +0.04 mV/°C range typical for 4.7–5.6 V Zeners in this family, as shown in Fig.9 of the datasheet.

Key Specifications

Pinout & Package

RD5.1S-T1-AT uses a 2-pin Super Mini Mold surface-mount package (SMD) with cathode indicated by a band. Dimensions: 2.5 ±0.15 mm length, 1.7 ±0.1 mm width, 1.25 ±0.1 mm height, 0.3 ±0.05 mm lead pitch, and 0.9 ±0.1 mm terminal length. Cathode marking is visible on top surface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode voltage reference and transient suppression applications.

Compared with RD5.1S-T1-AT, the 1N4733A-TAP offers higher power handling but sacrifices SMD integration, while the BZX55-C5V1 provides comparable regulation performance in a different package with greater power margin but less optimal low-current impedance.

Availability

RD5.1S-T1-AT is available at Aetrix Electronics and suitable for industrial sensor interfaces, microcontroller I/O protection, low-power battery monitoring, and LED current setting requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for RD5.1S-T1-AT 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 industrial, automotive, and infrastructure markets.

RD5.1S-T1-AT belongs to the RD2.0S–RD150S Zener diode family, engineered for compact, reliable voltage regulation and transient suppression in space-constrained, cost-sensitive consumer and industrial electronics.

FAQ

What is the exact Zener voltage range for RD5.1S-T1-AT at 5 mA?

The RD5.1S-T1-AT has a guaranteed Zener voltage range of 4.82 V to 5.39 V when tested at 5 mA DC current per the D11444EJ6V0DS datasheet. This range corresponds to Class B grading, with sub-bins B1 (4.82–5.06 V), B2 (4.96–5.22 V), and B3 (5.12–5.39 V) - actual unit binning is marked on packaging.

Does RD5.1S-T1-AT support reflow soldering, and what is its maximum peak temperature?

Yes, RD5.1S-T1-AT is qualified for standard lead-free reflow soldering. Its Super Mini Mold package withstands peak temperatures up to 260°C for 10 seconds, consistent with IPC/JEDEC J-STD-020 moisture sensitivity level (MSL) 1 rating - no pre-bake required for dry storage.

What is the thermal resistance and derating behavior of RD5.1S-T1-AT on a standard PCB?

RD5.1S-T1-AT exhibits linear thermal derating from 200 mW at 25°C ambient to 0 mW at 150°C on a 30 mm × 30 mm × 1.6 mm glass-epoxy PCB (Fig.1). This implies a transient thermal impedance of ~625°C/W and a slope of –1.33 mW/°C above 25°C - critical for sustained operation in enclosed enclosures.

Can RD5.1S-T1-AT be used as a substitute for a 5 V logic-level shunt reference?

RD5.1S-T1-AT is suitable as a basic 5 V shunt reference in non-critical applications, delivering 4.82–5.39 V with ≤130 Ω dynamic impedance at 5 mA. However, it lacks initial accuracy and tempco specs of dedicated references like TL431; use only where ±5% regulation and moderate temperature stability suffice.

Is RD5.1S-T1-AT compliant with RoHS and REACH regulations?

Yes, RD5.1S-T1-AT meets EU RoHS Directive 2011/65/EU and REACH SVHC requirements as confirmed by Renesas Electronics' material declarations. The device contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits, and is marked "Lead-Free" in official documentation.