onsemi 1N965BTR

Overview

1N965BTR from Fairchild Semiconductor is a 5% tolerance, 15 V nominal Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, and specified for operation from –65°C to +200°C. It delivers stable voltage regulation in low-power reference and protection circuits, such as power supply feedback loops and overvoltage clamp stages.

For engineers reviewing the 1N965BTR datasheet, pinout, applications, or equivalent options, key selection criteria include its 15 V nominal Zener voltage (min 14.25 V, typ 15 V, max 15.75 V), 8.5 Ω dynamic impedance at IZ = 16 mA, 5 μA maximum reverse leakage at VR = 12.2 V, and DO-35 mechanical compatibility with axial-leaded PCB layouts.

Technical Context

The 1N965BTR operates as a two-terminal voltage reference device relying on controlled avalanche breakdown in silicon PN junction. Its Zener voltage is specified at 16 mA test current (IZ), with dynamic impedance measured using 60 Hz AC signal at 0.1×IZ(dc) per JEDEC JESD24-A.

Thermal performance is defined by lead temperature (TL) at 3/8″ length, not case or ambient temperature. Power derating begins above 75°C, and storage/operating range extends to +200°C - enabling use in high-reliability industrial and automotive under-hood environments where thermal stability is critical.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode indicated by color band; no polarity-sensitive terminals beyond anode/cathode - standard two-terminal configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4744A and BZX55-C15, the 1N965BTR offers identical 15 V nominal voltage and DO-35 form factor as BZX55-C15 but with documented 8.5 Ω Z_Z at 16 mA, whereas 1N4744A trades precision for power - making 1N965BTR optimal for space-constrained, thermally demanding 15 V reference nodes.

Availability

1N965BTR is available at Aetrix Electronics and suitable for switch-mode power supplies, automotive overvoltage clamps, and industrial sensor signal conditioning requiring stable component supply across extended temperature ranges.

Supply support for 1N965BTR 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 designer and manufacturer of analog and discrete semiconductors, acquired by ON Semiconductor in 2016; legacy products maintain full datasheet compliance and industrial qualification.

The 1N957B–1N979B series was engineered specifically for high-stability, high-temperature voltage reference and protection roles in industrial controls, automotive subsystems, and telecom infrastructure where long-term parameter drift and thermal resilience are critical.

FAQ

What is the nominal Zener voltage and tolerance of the 1N965BTR?

The 1N965BTR has a nominal Zener voltage of 15 V with a ±5% tolerance, meaning its actual breakdown voltage falls between 14.25 V and 15.75 V when tested at 16 mA. This specification is verified per JEDEC JESD24-A under controlled thermal equilibrium conditions at lead temperature of 30°C ±1°C. The 1N965BTR maintains this tolerance across its full operating temperature range.

What package type does the 1N965BTR use, and how is polarity identified?

The 1N965BTR uses a DO-35 glass axial package with a cathode-indicating color band on the body. The anode and cathode leads are unmarked except for the band, which must be oriented toward the higher-potential node in reverse-bias regulation applications. This DO-35 construction provides hermetic sealing and supports operation up to +200°C - a key feature distinguishing the 1N965BTR from plastic-packaged alternatives.

What is the maximum power dissipation and derating behavior of the 1N965BTR?

The 1N965BTR is rated for 500 mW power dissipation at lead temperature (T_L) ≤ 75°C with 3/8″ lead length. Above 75°C, it derates linearly at 4.0 mW/°C. This thermal profile is defined by lead temperature, not ambient or case temperature, and directly impacts layout decisions - such as copper pour area and lead length - to maintain reliability in high-temperature environments where the 1N965BTR is commonly deployed.

How does the 1N965BTR's Zener impedance affect circuit performance?

The 1N965BTR exhibits 8.5 Ω dynamic impedance (Z_Z) at I_Z = 16 mA, measured with 60 Hz AC signal at 0.1×I_Z(dc). This value determines how much the output voltage shifts under changing load current - for example, a 10 mA step induces ~85 mV variation. Designers use this parameter to size series resistors and assess regulation stability in feedback networks where the 1N965BTR serves as a reference element.

Can the 1N965BTR replace the 1N4744A in existing designs?

The 1N965BTR is not a direct replacement for the 1N4744A due to differences in nominal voltage (15 V vs. 14 V), package (DO-35 vs. DO-41), and power rating (500 mW vs. 1 W). While both are Zener diodes, substituting the 1N965BTR requires verifying that the 1 V higher regulation point and reduced surge capability meet system requirements. The 1N965BTR also demands stricter thermal management due to its lower power rating compared to the 1N4744A.