onsemi 1N5250B_T50R

Overview

1N5250B_T50R from ON Semiconductor is a 20 V ±5% tolerance, 500 mW glass-encapsulated Zener diode in DO-35 package, designed for precision voltage regulation and reference applications in low-power analog circuits, power supply feedback loops, and overvoltage protection. It exhibits 25 Ω dynamic impedance at 19 mA test current, -0.086 %/°C temperature coefficient, and 0.1 μA reverse leakage at 15.2 V.

For engineers reviewing the 1N5250B_T50R datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, cathode identification per DO-35 marking convention, and validated alternatives for voltage reference design continuity.

Technical Context

The 1N5250B_T50R operates as a two-terminal silicon Zener diode with sharp reverse breakdown at nominal 20 V, optimized for stable DC voltage reference under fixed-current bias. Its DO-35 hermetically sealed glass package ensures long-term parameter stability and low leakage across -65°C to +200°C junction temperature range.

It is characterized at 25°C ambient with 19 mA Zener test current (IZ), 25 Ω dynamic impedance (ZZ), and 0.1 μA maximum reverse leakage (IR) at VR = 15.2 V - confirming suitability for low-drift, low-noise reference use where thermal coefficient (-0.086 %/°C) and tight 5% tolerance are critical.

Key Specifications

Pinout & Package

DO-35 glass axial package: hermetically sealed, 0.137 g mass, 2.0 mm diameter, 4.56 mm body length, 3.05 mm overall length, cathode identified by color band on glass body. Leads are tinned copper-clad steel, 0.46 mm diameter, 25.4 mm minimum straight length (T50).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5250BRLG and BZX55C20, the 1N5250B_T50R offers optimal balance of low dynamic impedance (25 Ω), superior temperature coefficient (-0.086 %/°C), and standardized ON Semiconductor marking - making it preferred for new designs requiring traceable, high-stability 20 V references.

Availability

1N5250B_T50R is available at Aetrix Electronics and suitable for voltage reference circuits, power supply feedback networks, and overvoltage clamp designs requiring stable component supply, consistent parametric performance, and DO-35 package compatibility.

Supply support for 1N5250B_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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, medical, and IoT applications.

The 1N52xxB series is part of ON Semiconductor's legacy Zener diode portfolio, engineered for general-purpose voltage regulation and precision reference use in cost-sensitive, reliability-critical linear power and signal conditioning circuits.

FAQ

What is the Zener voltage tolerance of the 1N5250B_T50R?

The 1N5250B_T50R has a Zener voltage tolerance of ±5% at 25°C, meaning its nominal 20 V breakdown voltage falls between 19 V and 21 V under specified test conditions (IZ = 19 mA). This tolerance is guaranteed per ON Semiconductor's 1N5221B–1N5263B datasheet Rev. 3, and applies to all units regardless of packaging format including the T50R variant.

Does the 1N5250B_T50R have a cathode marking, and how is it identified?

Yes, the 1N5250B_T50R uses the standard DO-35 axial package with a visible cathode band - a single color ring painted on the glass body near one end. Per JEDEC DO-204AH specification and ON Semiconductor marking guidelines, the banded end is the cathode, and the unmarked end is the anode. This marking is consistent across all 1N52xxB devices, including the 1N5250B_T50R.

What is the maximum power dissipation and thermal derating rate for the 1N5250B_T50R?

The 1N5250B_T50R has a maximum power dissipation of 500 mW at TA = 25°C, with a linear derating factor of 4.0 mW/°C above 50°C ambient temperature. This means usable power drops to 400 mW at 75°C and 300 mW at 100°C ambient - critical for thermal design in enclosed or high-temperature environments where the 1N5250B_T50R serves as a voltage reference.

How does the temperature coefficient of the 1N5250B_T50R affect its voltage reference accuracy?

With a temperature coefficient of -0.086 %/°C, the 1N5250B_T50R's Zener voltage decreases by approximately 17.2 mV per 10°C rise above 25°C. For example, at 65°C ambient, VZ shifts by -3.44 V × 0.00086 = -34.4 mV, resulting in ~19.966 V output. This predictable drift enables compensation in precision systems, distinguishing the 1N5250B_T50R from higher-TC alternatives in the same family.

Is the 1N5250B_T50R suitable for use in low-leakage analog front-end circuits?

Yes, the 1N5250B_T50R is suitable due to its guaranteed maximum reverse leakage current of 0.1 μA at VR = 15.2 V, measured per ON Semiconductor's test conditions. This ultra-low leakage avoids loading high-impedance nodes - such as op-amp reference inputs or RC timing networks - ensuring signal integrity in sensitive analog front-end circuits where the 1N5250B_T50R provides stable 20 V bias.