onsemi BZX55C2V4_T50R

Overview

BZX55C2V4_T50R from Fairchild Semiconductor is a 2.4 V, ±5% tolerance Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 85 Ω dynamic impedance at 5 mA test current, used for voltage regulation and reference in low-power analog circuits.

For engineers reviewing the BZX55C2V4_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage accuracy, thermal derating behavior, reverse leakage at operating temperature, and DO-35 mechanical compatibility in space-constrained PCB layouts.

Technical Context

The BZX55C2V4_T50R operates as a silicon planar Zener diode with sharp reverse breakdown at 2.4 V nominal, designed for stable DC voltage reference and overvoltage clamping in linear power supplies and sensor bias networks. Its 5 mA test current and 85 Ω dynamic impedance reflect optimized trade-offs between regulation precision and low-current stability.

It supports operation across –65°C to +200°C junction and storage temperature range, with 0.1 μA maximum reverse leakage at 1 V reverse voltage and 155 mA maximum zener current at 25°C - parameters critical for battery-powered and automotive under-hood applications requiring long-term drift stability.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode indicated by color band; two-terminal device with no internal polarity reversal or auxiliary pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4730A and MMSZ4678, the BZX55C2V4_T50R offers optimal balance of DO-35 mechanical reliability, 500 mW thermal capability, and 85 Ω regulation impedance - making it preferred for legacy through-hole designs requiring proven field reliability and moderate power density.

Availability

BZX55C2V4_T50R is available at Aetrix Electronics and suitable for voltage reference, sensor biasing, overvoltage clamping, and microcontroller reset circuits requiring stable component supply across industrial, automotive, and instrumentation programs.

Supply support for BZX55C2V4_T50R 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The BZX55 series was developed as a general-purpose Zener diode family targeting cost-effective, thermally robust voltage regulation in consumer, industrial, and automotive electronics.

FAQ

What is the exact Zener voltage range for BZX55C2V4_T50R at 5 mA test current?

The BZX55C2V4_T50R has a guaranteed Zener voltage range of 2.28 V minimum to 2.56 V maximum at 5 mA test current and 25°C ambient, reflecting its ±5% tolerance specification per the Fairchild BZX55C2V4 datasheet Rev. D1. This range remains valid under standard lead temperature conditions (TL ≤ 75°C) and defines the usable regulation window for precision reference design.

Does BZX55C2V4_T50R support operation at elevated temperatures like 125°C?

Yes, the BZX55C2V4_T50R is rated for junction and storage temperatures from –65°C to +200°C. While its electrical characteristics (e.g., V_Z, I_R) are specified at 25°C, the device maintains functional integrity at 125°C - though reverse leakage increases to 100 μA and power must be derated by 4.0 mW/°C above 75°C per the absolute maximum ratings table.

What is the cathode identification method on BZX55C2V4_T50R?

The cathode of the BZX55C2V4_T50R is identified by a distinct color band on the DO-35 glass body, consistent with industry-standard marking for axial-leaded Zener diodes. This band aligns with the "5C" second-line top mark and the "2V4" third-line voltage code, confirming polarity for correct reverse-bias connection in regulation circuits.

How does the dynamic impedance of BZX55C2V4_T50R affect regulation performance?

The BZX55C2V4_T50R exhibits 85 Ω dynamic impedance at 5 mA, meaning a 1 mA change in zener current produces approximately 85 mV shift in regulated voltage. This value directly impacts load regulation accuracy - lower Z_Z yields tighter voltage control, making the BZX55C2V4_T50R suitable for applications where supply ripple rejection and line regulation are critical.

Can BZX55C2V4_T50R replace BZX55C2V7_T50R in an existing circuit?

No - the BZX55C2V4_T50R (2.4 V nominal) is not a direct replacement for BZX55C2V7_T50R (2.7 V nominal), as their zener voltages differ by 0.3 V and fall into separate tolerance bands. Substitution would alter reference or clamp thresholds, potentially causing regulator instability or undervoltage lockout failure. Always verify circuit margin requirements before interchanging BZX55 variants.