onsemi 1N4758A_T50R

Overview

1N4758A_T50R from ON Semiconductor is a 56 V, ±5% tolerance, 1.0 W axial-leaded Zener diode in DO-41 glass package, rated for 4.5 mA test current, with 110 Ω dynamic impedance at I_Z, 80 mA non-repetitive peak reverse current, and operating temperature range of –65 °C to +200 °C - used for precision voltage regulation in power supply feedback loops and overvoltage protection circuits.

For engineers reviewing the 1N4758A_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage accuracy (53.2–58.8 V), thermal derating (6.67 mW/°C above 50 °C), low leakage (<0.25 µA at 42.6 V), and robust surge capability (2000 mA I_ZSM).

Technical Context

This discrete Zener diode operates in reverse breakdown mode to maintain stable reference voltage under varying load and line conditions. Its DO-41 package supports through-hole mounting with 3/8″ lead length for 1.0 W power dissipation at T_L ≤ 50 °C, and thermal performance is validated across –65 °C to +200 °C junction and storage range.

Electrical behavior is defined by three critical operating points: nominal Zener voltage (56 V) at 4.5 mA test current, knee impedance (110 Ω at I_Z), and low-current regulation threshold (I_ZK = 0.25 mA), with leakage current limited to ≤0.25 µA at 42.6 V (80% of V_Z).

Key Specifications

Pinout & Package

DO-41 glass axial package with cathode indicated by color band; two-terminal device requiring no orientation-specific PCB layout beyond cathode/anode polarity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4758A_T50R, the base 1N4758A offers identical performance in different packaging, while BZX85C56 provides lower impedance at higher test current - enabling better ripple rejection in high-precision analog supplies but demanding revised bias network design.

Availability

1N4758A_T50R is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, programmable voltage references, and temperature-stable bias generators requiring stable component supply and full traceability.

Supply support for 1N4758A_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 1N47xxA series was designed as a standardized, high-reliability family of general-purpose Zener diodes targeting cost-sensitive, high-volume applications requiring consistent voltage regulation and rugged thermal performance.

FAQ

What is the Zener voltage tolerance for 1N4758A_T50R?

The 1N4758A_T50R has a ±5% Zener voltage tolerance, meaning its actual breakdown voltage falls between 53.2 V and 58.8 V at the specified 4.5 mA test current. This tolerance is guaranteed per ON Semiconductor's 1N4728A–1N4758A datasheet Rev. 8, and applies across the full operating temperature range. The 1N4758A_T50R achieves this using tightly controlled diffusion processes in the DO-41 glass package.

Can 1N4758A_T50R be used in surface-mount designs?

No - the 1N4758A_T50R is packaged in the DO-41 axial-leaded glass case, which is intended for through-hole mounting only. It lacks solder pads or terminations compatible with reflow or wave soldering for SMT assembly. For surface-mount equivalents, consider SOD-123 or SOD-80 packages like MMBZ5256B, but note that those differ in power rating, impedance, and thermal profile from the 1N4758A_T50R.

What is the maximum allowable ambient temperature for continuous operation of 1N4758A_T50R?

The 1N4758A_T50R supports continuous operation up to +200 °C junction temperature, but ambient temperature limits depend on PCB layout and lead length. With 3/8″ leads at T_L ≤ 50 °C, full 1.0 W dissipation is allowed; above 50 °C, derating is 6.67 mW/°C. At 75 °C ambient, max power drops to ~833 mW. The 1N4758A_T50R must be mounted with adequate copper pour and airflow to avoid exceeding T_J = 200 °C.

How does leakage current affect performance of 1N4758A_T50R in high-impedance circuits?

The 1N4758A_T50R exhibits ≤0.25 µA leakage current at 42.6 V (80% of nominal V_Z), making it suitable for high-impedance voltage dividers and reference nodes where error current must be minimized. In a 1 MΩ upper-divider resistor, this leakage introduces <0.25 V offset - negligible for most 56 V regulation tasks. The 1N4758A_T50R's low I_R ensures stability in battery-powered or low-power sensor interfaces.

Is 1N4758A_T50R RoHS compliant and halogen-free?

Yes - the 1N4758A_T50R meets RoHS Directive 2011/65/EU and is halogen-free per ON Semiconductor's product compliance documentation. The DO-41 glass package contains no lead in solderable terminations, and all materials comply with JEDEC J-STD-609A Class 1 moisture sensitivity. Full compliance data for the 1N4758A_T50R is available in ON Semi's "Product Compliance Status" database under part number 1N4758AT50R.