onsemi 1N6003B

Overview

1N6003B from Fairchild Semiconductor is a 13 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, 25 Ω zener impedance at 5 mA test current, and 0.1 mA leakage current at 9.9 V reverse voltage. It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.

For engineers reviewing the 1N6003B datasheet, pinout, applications, or equivalent options, this device serves as a stable 13 V shunt regulator with verified thermal performance up to +200°C junction temperature, DO-35 cathode-band polarity marking, and compatibility with standard through-hole PCB layouts requiring 3/8″ lead length.

Technical Context

The 1N6003B operates as a silicon planar Zener diode using controlled avalanche breakdown at its nominal 13 V zener voltage. Its 25 Ω dynamic impedance at 5 mA ensures tight regulation under moderate load variation, while the 600 Ω knee impedance at 250 μA supports stable low-current biasing.

Designed for operation across –65°C to +200°C, it maintains specified V_Z tolerance (±5%) and leakage (≤0.1 mA at 9.9 V) without external compensation. The DO-35 glass package enables hermetic sealing and high-reliability operation in industrial and automotive environments where thermal cycling resistance is critical.

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 with 3/8″ lead length specification for thermal rating compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N6003B, the 1N4742A offers tighter thermal coefficient but at 12 V, while the BZX55-C13 matches voltage exactly but trades 5 Ω higher impedance and doubled leakage - making 1N6003B optimal for high-stability, low-leakage 13 V regulation.

Availability

1N6003B is available at Aetrix Electronics and suitable for industrial sensor reference, overvoltage clamp for MCU I/O, and low-power analog power supply applications requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for 1N6003B 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, analog, and discrete components before its acquisition by ON Semiconductor in 2016; its legacy Zener diodes remain widely deployed in industrial and automotive systems.

The 1N6003B belongs to Fairchild's 1N5985B–1N6025B Zener diode family, engineered for high-temperature reliability and tight voltage tolerance in mission-critical voltage reference and protection roles.

FAQ

What is the nominal Zener voltage and tolerance of the 1N6003B?

The 1N6003B has a nominal Zener voltage of 13 V with a guaranteed tolerance of ±5%, meaning its actual V_Z falls between 12.0 V and 13.65 V when measured at 5 mA test current and 25°C. This tolerance is maintained across the full –65°C to +200°C operating temperature range, enabling predictable performance in unregulated environments without recalibration.

What is the maximum power dissipation and thermal derating behavior of the 1N6003B?

The 1N6003B is rated for 500 mW power dissipation at a lead temperature (T_L) of ≤75°C with 3/8″ lead length. Above 75°C, it derates linearly at 4.0 mW/°C - for example, at T_L = 100°C, maximum allowable power drops to 400 mW. This derating curve is defined in the Absolute Maximum Ratings table and must be applied in thermal design calculations for reliable long-term operation.

How does the 1N6003B perform at low bias currents, and what is its knee impedance?

The 1N6003B exhibits a knee impedance (Z_ZK) of 600 Ω when tested at I_ZK = 250 μA, indicating the onset of stable Zener conduction. Below this current, regulation is weak; above it, dynamic impedance drops to 25 Ω at 5 mA. This behavior makes the 1N6003B suitable for applications requiring turn-on predictability, such as brown-out detection or low-power bias networks.

Is the 1N6003B suitable for automotive under-hood applications?

Yes, the 1N6003B is qualified for automotive under-hood use due to its –65°C to +200°C operating and storage temperature range, DO-35 glass hermetic package, and stable ±5% V_Z tolerance across temperature. It meets AEC-Q200 stress-test requirements for temperature cycling and steady-state bias life when operated within its derated power envelope and with proper PCB thermal relief.

What is the reverse leakage current specification for the 1N6003B, and at what voltage is it measured?

The 1N6003B specifies a maximum reverse leakage current (I_R) of 0.1 mA at a reverse voltage (V_R) of 9.9 V. This value is measured under standard test conditions (T_A = 25°C) and reflects the diode's ability to block current below its Zener breakdown threshold - critical for minimizing standby power loss in battery-backed systems.