Nexperia USA Inc. BZX79-C4V3,133

Overview

BZX79-C4V3,133 from Nexperia is a ±5% tolerance Zener voltage regulator diode in DO-35 (SOD27) glass package, rated for 4.3 V nominal stabilization at 5 mA test current, with 410 Ω typical differential resistance and −2.5 mV/K temperature coefficient. It delivers low-voltage reference stability in power supply feedback loops and analog sensor biasing circuits.

For engineers reviewing the BZX79-C4V3,133 datasheet, BZX79-C4V3,133 pinout, BZX79-C4V3,133 application, or BZX79-C4V3,133 equivalent, this part serves as a cost-optimized, through-hole Zener reference for <5 V rail regulation, requiring verification of thermal derating at >50 °C ambient and reverse leakage under low-current bias conditions.

Technical Context

This Zener diode operates in reverse breakdown mode with a nominal 4.3 V stabilization voltage at I_Z = 5 mA, exhibiting a typical differential resistance of 410 Ω and a negative temperature coefficient of −2.5 mV/K - indicating voltage decreases with rising junction temperature. Its non-repetitive peak reverse power dissipation is rated at 40 W for 100 μs pulses.

The device is hermetically sealed in a glass axial package (DO-35/SOD27), with cathode identified by a band. Thermal resistance from junction to tie-point is 300 K/W, and maximum continuous power dissipation is 500 mW at T_amb = 50 °C with 8 mm lead length.

Key Specifications

Pinout & Package

Two-terminal axial device in DO-35 (SOD27) glass package: anode (unmarked end) and cathode (band-marked end). No internal circuitry; polarity must be observed in PCB layout to ensure reverse-bias operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX79-C4V3,133, the 1N4733A offers superior dynamic regulation but demands mechanical redesign, while the BZX79-B4V3,133 delivers tighter DC accuracy without layout change - making it ideal for yield-sensitive production runs where binning cost outweighs tolerance risk.

Availability

BZX79-C4V3,133 is available at Aetrix Electronics and suitable for low-voltage stabilization, sensor biasing, and overvoltage protection requiring stable component supply in automotive body electronics, industrial control modules, and consumer power adapters.

Supply support for BZX79-C4V3,133 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

Nexperia is a global leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products division, with focus on automotive, industrial, and computing markets.

This device belongs to the BZX79 series of low-power Zener diodes designed for cost-sensitive, through-hole voltage reference and stabilization in legacy and space-constrained analog circuits.

FAQ

What is the maximum continuous reverse current this diode can handle at 4.3 V?

The BZX79-C4V3,133 is not rated for continuous reverse current at its Zener voltage; instead, it is characterized by test current I_Z = 5 mA for specification. Continuous operation should remain within P_tot = 500 mW limit - implying max I_Z ≈ 116 mA at 4.3 V, but thermal derating above 50 °C ambient reduces practical safe current significantly.

Can this diode replace a 3.3 V Zener in a 3.3 V rail clamp?

No - its nominal 4.3 V Zener voltage exceeds 3.3 V by 1 V, making it unsuitable as a clamp for that rail. Clamping would occur only during overvoltage events >4.3 V, leaving the 3.3 V rail unprotected below that threshold. A BZX79-C3V3,133 (3.3 V) or BZX79-C3V6,133 (3.6 V) is appropriate for 3.3 V rail protection.

How does the −2.5 mV/K temperature coefficient affect circuit performance?

This negative coefficient means the Zener voltage drops by 2.5 mV per Kelvin rise in junction temperature. In a 50 °C to 100 °C operating range, V_Z shifts ~−125 mV - a −2.9% change. Designers must account for this drift in precision references or use compensation techniques like matched transistor pairs.

Is the DO-35 package RoHS compliant and lead-free?

Yes - Nexperia's BZX79-C4V3,133 in DO-35 package is RoHS compliant and lead-free, meeting JEDEC J-STD-609 Category 1 requirements. The glass body and SnAgCu solder-compatible leads support standard reflow and wave soldering processes without exemption requests.