onsemi BZX55C47_T50R

Overview

BZX55C47_T50R from Fairchild Semiconductor is a 47 V ±5% tolerance Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C, with 110 Ω dynamic impedance at 2.5 mA test current and 0.1 μA maximum reverse leakage at 35 V. It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.

For engineers reviewing the BZX55C47_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior, cathode identification via band marking, and compatibility with through-hole PCB layouts requiring DO-35 footprint compliance.

Technical Context

The BZX55C47_T50R operates as a silicon planar Zener diode optimized for stable voltage reference generation in DC bias networks and clamping functions. Its 47 V nominal breakdown voltage is specified at 2.5 mA test current, with 110 Ω dynamic impedance indicating moderate regulation stiffness under small-signal conditions.

Thermal performance is defined by a 4.0 mW/°C derating slope above 75°C lead temperature and a -65°C to +200°C operating/storage range. Reverse leakage remains ≤0.1 μA at 35 V, supporting high-impedance sensing nodes where leakage-induced error must be minimized.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode identified by a single color band on the body. Leads are tinned copper-clad steel, suitable for wave or hand soldering. Package outline conforms to JEDEC DO-35 standard (length ≈ 4.2 mm, diameter ≈ 1.9 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4752A and BZX55C47-TR, the BZX55C47_T50R offers identical Zener characteristics in a legacy DO-35 form factor optimized for manual prototyping and low-volume through-hole builds, while maintaining full interchangeability in voltage reference roles where power demand stays within 500 mW limits.

Availability

BZX55C47_T50R is available at Aetrix Electronics and suitable for industrial power supply reference, automotive sensor bias networks, test equipment voltage calibrators, and telecom line interface protection requiring stable component supply and long-lifecycle support.

Supply support for BZX55C47_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, signal conditioning, 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, reliable voltage regulation in analog circuits, with emphasis on tight tolerance, low leakage, and wide temperature operation.

FAQ

What is the Zener voltage tolerance for BZX55C47_T50R?

The BZX55C47_T50R has a ±5% Zener voltage tolerance, meaning its breakdown voltage ranges from 44 V to 50 V at the specified 2.5 mA test current. This tolerance is guaranteed across the full operating temperature range and reflects the device's classification as a "C" grade Zener in the BZX55 series. The BZX55C47_T50R achieves this consistency through process-controlled doping and post-trim screening.

How does thermal derating affect BZX55C47_T50R's power handling?

The BZX55C47_T50R dissipates 500 mW up to a lead temperature of 75°C, then derates linearly at 4.0 mW/°C beyond that point. At 100°C lead temperature, its usable power drops to 400 mW. This derating curve is critical for reliability in enclosed or high-ambient environments. The BZX55C47_T50R's -65°C to +200°C operating range ensures functionality even when junction temperatures approach limits.

Is BZX55C47_T50R suitable for use as a voltage reference in precision circuits?

Yes, the BZX55C47_T50R supports precision reference use due to its 110 Ω dynamic impedance at 2.5 mA and ≤0.1 μA reverse leakage at 35 V. These parameters minimize voltage drift under load and reduce error in high-impedance dividers. While not a temperature-compensated reference, the BZX55C47_T50R delivers stable performance in ambient-stable applications where ±5% initial tolerance is acceptable.

What package type does BZX55C47_T50R use and how is polarity marked?

The BZX55C47_T50R uses a DO-35 glass axial package with leads extending from both ends. Polarity is marked by a single color band near one end, denoting the cathode terminal. This band aligns with JEDEC standard marking conventions and ensures correct orientation during manual or automated assembly. The BZX55C47_T50R's DO-35 footprint is widely supported in legacy and prototyping PCB libraries.

Can BZX55C47_T50R replace other 47 V Zener diodes in existing designs?

The BZX55C47_T50R can directly replace other DO-35-packaged 47 V Zeners with ±5% tolerance, such as BZX55C47-TR or earlier BZX55C47 variants, provided lead length and thermal environment match the 3/8″ specification. It is not a drop-in replacement for DO-41 devices like 1N4752A due to different mechanical dimensions and thermal mass, though electrical behavior is functionally equivalent within its 500 mW limit.