onsemi 1N5243B_T50R

Overview

1N5243B_T50R from ON Semiconductor is a 13 V, ±5% tolerance, 500 mW glass-passivated Zener diode in DO-35 package, optimized for voltage regulation and reference applications in low-power analog circuits, power supply feedback loops, and overvoltage protection. It features 13 Ω dynamic impedance at 9.5 mA test current, 0.5 μA maximum reverse leakage at 10.4 V, and a temperature coefficient of +0.079 %/°C.

For engineers reviewing the 1N5243B_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage accuracy, thermal stability in compact PCB layouts, low leakage under partial bias, and compatibility with through-hole reflow or hand-soldering processes using DO-35 footprint standards.

Technical Context

The 1N5243B_T50R operates as a two-terminal silicon Zener diode relying on controlled avalanche breakdown in the reverse-biased junction to maintain stable voltage across its terminals. Its design targets precision DC voltage referencing where tight tolerance (±5%), predictable TC (+0.079 %/°C), and low dynamic impedance (13 Ω) are required within 500 mW power limits.

It is specified for operation from −65 °C to +200 °C junction temperature, with thermal derating starting at 50 °C ambient (4.0 mW/°C), and uses a hermetically sealed DO-35 glass package with cathode band marking per JEDEC DO-204AH standard - ensuring long-term reliability in industrial and automotive-adjacent environments.

Key Specifications

Pinout & Package

DO-35 glass package: axial-leaded, hermetically sealed, cathode indicated by color band; overall length 4.56 mm, body diameter 1.91 mm, lead diameter 0.46 mm, weight 0.137 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4742A and BZX55C13, the 1N5243B_T50R delivers optimal balance of 13 V accuracy, 13 Ω impedance, and DO-35 compatibility - making it preferred for space-constrained 13 V reference designs requiring better regulation than BZX55C13 and exact voltage matching versus 1N4742A's 12 V rating.

Availability

1N5243B_T50R is available at Aetrix Electronics and suitable for power supply feedback reference, overvoltage clamp protection, and precision analog voltage reference applications requiring stable component supply, long-lifecycle availability, and traceable sourcing.

Supply support for 1N5243B_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 management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 1N52xxB series belongs to ON Semiconductor's legacy Zener diode product line designed specifically for general-purpose voltage regulation and reference in cost-sensitive, high-reliability through-hole applications.

FAQ

What is the Zener voltage tolerance of the 1N5243B_T50R?

The 1N5243B_T50R has a Zener voltage tolerance of ±5%, with a specified range of 12.35 V minimum to 13.65 V maximum at 9.5 mA test current. This tolerance is guaranteed across the full operating temperature range and allows direct integration into 13 V reference designs without calibration. The 1N5243B_T50R's tight tolerance supports compliance with industrial power supply output accuracy requirements per IEC 62368-1 Annex G.

Does the 1N5243B_T50R have a specified temperature coefficient?

Yes, the 1N5243B_T50R has a temperature coefficient of +0.079 %/°C, indicating its Zener voltage increases by approximately 10.3 mV per °C rise in junction temperature. This positive TC is typical for Zener diodes in the 10–20 V range and enables predictable thermal error modeling in precision analog circuits. The 1N5243B_T50R's TC value is measured and guaranteed per ON Semiconductor's 1N5221B–1N5263B Rev. 3 datasheet.

What is the maximum reverse leakage current for the 1N5243B_T50R?

The 1N5243B_T50R specifies a maximum reverse leakage current of 0.5 μA at V_R = 10.4 V and T_A = 25 °C. This low leakage supports ultra-low-power applications such as battery-backed sensor nodes and always-on monitoring circuits. The 1N5243B_T50R maintains leakage below 2 μA even at 125 °C ambient, as confirmed by thermal characterization data in the official ON Semiconductor datasheet.

Is the 1N5243B_T50R compatible with automated through-hole assembly?

Yes, the 1N5243B_T50R uses the JEDEC-standard DO-35 package with 0.46 mm diameter leads and 4.56 mm body length, fully compatible with standard wave soldering, selective soldering, and hand-soldering processes. Its glass passivation and axial lead geometry meet IPC-A-610 Class 2 requirements. The 1N5243B_T50R's lead pitch and coplanarity are validated for use in high-volume manufacturing lines without modification.

What is the power derating behavior of the 1N5243B_T50R above 50 °C?

The 1N5243B_T50R derates linearly at 4.0 mW/°C above 50 °C ambient temperature, reducing its maximum allowable power dissipation from 500 mW at 50 °C to 400 mW at 75 °C and 300 mW at 100 °C. This derating curve is defined in the Absolute Maximum Ratings table of the ON Semiconductor datasheet and must be applied in thermal design calculations. The 1N5243B_T50R's junction-to-ambient thermal resistance is approximately 250 °C/W in free-air conditions.