onsemi BZX55C3V6_T50R

Overview

BZX55C3V6_T50R from Fairchild Semiconductor is a 3.6 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 and 2 μA reverse leakage at 1 V reverse voltage. It provides precise voltage regulation in low-power reference and protection circuits.

For engineers reviewing the BZX55C3V6_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage accuracy, thermal derating behavior, cathode-band polarity marking, DO-35 mechanical compatibility, and compliance with industrial temperature range (–65°C to +200°C).

Technical Context

This device operates as a two-terminal voltage reference, clamping reverse-biased voltage at its nominal 3.6 V zener point with tight 5% tolerance. Its 85 Ω dynamic impedance ensures stable regulation under varying load currents up to IZM = 105 mA.

The DO-35 glass package features axial leads with cathode band marking, enabling manual or automated placement in through-hole PCBs. Thermal performance follows a linear 4.0 mW/°C derating above 75°C ambient lead temperature.

Key Specifications

Pinout & Package

DO-35 glass axial-leaded package with cathode indicated by a color band on the body; no active pin numbering-cathode and anode are unidirectional terminals defined by physical marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4728A and BZX55C3V9, BZX55C3V6_T50R offers optimal balance of 3.6 V regulation, low leakage, and industry-standard DO-35 form factor-ideal for feedback references where exact 3.6 V alignment matters more than peak current capacity.

Availability

BZX55C3V6_T50R is available at Aetrix Electronics and suitable for power supply feedback, overvoltage protection, and low-power sensor biasing requiring stable component supply across industrial, automotive, and instrumentation programs.

Supply support for BZX55C3V6_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 designed as a general-purpose, cost-effective Zener diode family targeting voltage reference and protection functions in consumer, industrial, and computing applications.

FAQ

What is the nominal zener voltage of BZX55C3V6_T50R?

The nominal zener voltage of BZX55C3V6_T50R is 3.6 V, with a guaranteed range of 3.4 V to 3.8 V at 5 mA test current and 25°C ambient. This value is measured under thermal equilibrium conditions with 3/8″ lead length and reflects the device's primary function as a precision voltage reference in low-power circuits.

Does BZX55C3V6_T50R have polarity marking, and how is it identified?

Yes, BZX55C3V6_T50R uses a cathode band marking on the DO-35 glass body to indicate polarity. The banded end is the cathode terminal, which must be connected to the higher-potential node during reverse-bias operation. This marking aligns with JEDEC standards and ensures correct orientation during manual or automated assembly.

What is the maximum power dissipation for BZX55C3V6_T50R, and how does it change with temperature?

BZX55C3V6_T50R has a maximum power dissipation of 500 mW at lead temperature ≤ 75°C. Above that temperature, it derates linearly at 4.0 mW/°C. This means at 100°C lead temperature, allowable power drops to 400 mW, ensuring safe operation within thermal limits without requiring additional heatsinking in standard PCB layouts.

How does the dynamic impedance of BZX55C3V6_T50R affect circuit performance?

The dynamic impedance of BZX55C3V6_T50R is 85 Ω at 5 mA, meaning a 1 mA change in zener current causes approximately 85 mV shift in regulated voltage. This directly impacts stability in feedback networks and clamp accuracy-lower Z_Z values would improve regulation, but 85 Ω is typical for this class and sufficient for most non-critical reference applications.

Is BZX55C3V6_T50R suitable for automotive under-hood applications?

Yes, BZX55C3V6_T50R is rated for operation from –65°C to +200°C and packaged in hermetically sealed DO-35 glass, making it suitable for under-hood automotive environments. Its robust thermal range and stable zener characteristics support use in engine control modules, battery management interfaces, and other high-temperature subsystems where reliability is critical.