onsemi 1N5933B

Overview

1N5933B from ON Semiconductor is a 3 W axial-lead Zener diode with nominal Zener voltage of 22 V, ±5% tolerance, 17.0 Ω maximum Zener impedance at 17.5 mA test current, and 0.25 μA maximum reverse leakage at 16.7 V. It regulates voltage in low-power analog reference and overvoltage protection circuits operating from −65 °C to +200 °C.

For engineers reviewing the 1N5933B datasheet, pinout, applications, or equivalent options, this device serves as a stable, high-ESD (Class 3, >16 kV HBM), surge-rated (98 W @ 1 ms) voltage reference for industrial power supplies, sensor biasing, and precision comparator thresholds where DO−41 package compatibility and lead temperature derating (3 W @ TL = 75 °C) are critical.

Technical Context

The 1N5933B operates as a silicon-oxide passivated junction Zener regulator, delivering precise reverse breakdown at 22 V with tight ±5% tolerance and low dynamic impedance (17.0 Ω at IZT = 17.5 mA). Its thermal design relies on lead-to-ambient conduction, with junction temperature derived from measured lead temperature (TL) plus transient junction-to-lead resistance (θJL).

It features a cathode-band polarity indicator, void-free thermosetting plastic case (CASE 59), and Pb-free DO−41 packaging. Surge capability is defined by non-repetitive rectangular pulses (98 W @ 1 ms), not DC derating curves - exceeding Figure 3 limits risks localized current crowding and degradation.

Key Specifications

Pinout & Package

Package: DO−41 (CASE 59), axial-lead, plastic-encapsulated, cathode indicated by band. Dimensions: A = 4.10–5.20 mm (length), B = 2.00–2.70 mm (diameter), D = 0.71–0.86 mm (lead diameter).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5933B, 1N5352B offers higher power headroom but demands mechanical redesign, while BZX85C22 fits the same DO-41 footprint but cannot sustain 3 W loads - making 1N5933B the optimal balance of power, impedance, and drop-in compatibility for mid-range industrial references.

Availability

1N5933B is available at Aetrix Electronics and suitable for industrial power supply references, sensor biasing circuits, overvoltage protection clamps, and comparator threshold generators requiring stable component supply and long-term obsolescence management.

Supply support for 1N5933B 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 (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 1N5933B belongs to the 1N5913B Series of 3 W Zener regulators designed for robust voltage reference and clamping in harsh-environment industrial and automotive applications where reliability, ESD immunity, and wide temperature operation are mandatory.

FAQ

What is the Zener voltage tolerance of the 1N5933B?

The 1N5933B has a ±5% Zener voltage tolerance, meaning its reverse breakdown voltage is guaranteed between 20.9 V and 23.1 V when measured at I_ZT = 17.5 mA and lead temperature T_L = 30 °C. This tolerance is marked by the "B" suffix in the part number and applies across the full operating temperature range of −65 °C to +200 °C.

Can the 1N5933B be used in surface-mount designs?

No, the 1N5933B is exclusively available in the axial-lead DO−41 (CASE 59) package and is not offered in SMD variants. Its mechanical construction - including 3/8″ lead length specification and lead-to-ambient thermal path - is optimized for through-hole mounting with heat sinking via leads. For SMD alternatives, consider the MMBZ5242B or similar SOT-23 Zeners, but note differences in power rating and thermal behavior.

What is the maximum reverse leakage current for the 1N5933B?

The 1N5933B specifies a maximum reverse leakage current (I_R) of 0.25 μA at V_R = 16.7 V and T_L = 30 °C. This ultra-low leakage ensures minimal loading in high-impedance reference divider networks and preserves accuracy in precision analog circuits such as sensor excitation and ADC reference buffers.

How does the 1N5933B handle surge conditions?

The 1N5933B is rated for 98 W non-repetitive surge power at 1 ms pulse width, as defined in Figure 3 of its datasheet. This capability is independent of DC derating curves and must not be extrapolated from thermal resistance data. Exceeding this limit risks localized junction damage due to current crowding, even if average power remains within 3 W limits.

Is the 1N5933B RoHS compliant and lead-free?

Yes, the "G" suffix in 1N5933B, G explicitly denotes a Pb-free package compliant with RoHS Directive 2011/65/EU. The device uses lead-free terminations and thermosetting plastic encapsulation, and supports soldering at 260 °C for 10 seconds at 1/16″ from the case - fully compatible with standard lead-free reflow profiles.