Nexperia USA Inc. BZX79-B4V7,133

Overview

BZX79-B4V7,133 from Nexperia is a ±2% tolerance Zener voltage regulator diode in a hermetically sealed SOD27 (DO-35) glass package, rated for 4.7 V nominal stabilization at 5 mA test current, with 425 Ω typical differential resistance and −1.4 mV/K temperature coefficient. It delivers low-power voltage reference functionality in space-constrained analog circuits requiring stable biasing or precision clamping.

For engineers reviewing the BZX79-B4V7,133 datasheet, BZX79-B4V7,133 pinout, BZX79-B4V7,133 application, or BZX79-B4V7,133 equivalent, this part supports design of compact, cost-sensitive voltage references where tight tolerance, low leakage (<3 μA at VR = 2 V), and thermal stability across −65 °C to +200 °C are critical.

Technical Context

This Zener diode operates in reverse breakdown mode with a nominal working voltage of 4.7 V at I_Ztest = 5 mA, exhibiting a typical differential resistance of 425 Ω and a negative temperature coefficient of −1.4 mV/K - indicating decreasing Zener voltage with rising junction temperature. Its low 300 pF capacitance at 0 V reverse bias enables use in moderate-frequency reference and clamping applications.

Designed for DC or low-duty-cycle transient regulation, it supports non-repetitive peak reverse power dissipation up to 40 W for 100 μs pulses, with total continuous power dissipation limited to 500 mW at T_amb = 50 °C and 400 mW at T_amb = 50 °C with PCB mounting per note 1. Junction-to-ambient thermal resistance is 380 K/W under standard lead conditions.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode indicated by a black band. Dimensions: D = 1.85 mm max., L = 25.4 mm min., b = 0.56 mm max. Lead spacing accommodates standard through-hole PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4732A and BZX84-C4V7, BZX79-B4V7,133 offers tighter ±2% tolerance and documented −1.4 mV/K tempco - making it preferable for analog circuits demanding initial accuracy and predictable thermal behavior, despite its through-hole DO-35 form factor.

Availability

BZX79-B4V7,133 is available at Aetrix Electronics and suitable for low-voltage reference sources, overvoltage clamp circuits, and power supply feedback dividers requiring stable component supply across industrial, computing, and consumer electronics programs.

Supply support for BZX79-B4V7,133 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, serving automotive, industrial, computing, and consumer markets with high-volume, high-reliability components.

The BZX79 series belongs to Nexperia's legacy Zener diode product line, engineered specifically for cost-effective, precision DC voltage regulation and clamping in general-purpose analog and power management circuits.

FAQ

What is the maximum continuous Zener current for BZX79-B4V7,133 at 25 °C ambient?

The device does not specify a maximum continuous Zener current directly, but limits total power dissipation to 500 mW at T_amb = 50 °C. At 25 °C, derating is not required; thus, I_Zmax ≈ 500 mW / 4.7 V ≈ 106 mA - though practical operation is typically limited to ≤50 mA to maintain stability and avoid thermal runaway in unheatsinked configurations.

Is BZX79-B4V7,133 suitable for use in automotive under-hood applications?

Yes - its −65 °C to +200 °C junction temperature range, hermetic glass package, and AEC-Q200-unqualified (but widely deployed) robustness make it suitable for non-safety-critical under-hood functions such as sensor biasing and power rail monitoring, provided board-level thermal design maintains T_j within limits and transient protection meets ISO 7637-2 requirements.

How does the −1.4 mV/K temperature coefficient affect circuit performance?

This negative coefficient means the Zener voltage decreases by ~1.4 mV per Kelvin rise in junction temperature. Over a 100 K rise (e.g., from 25 °C to 125 °C), V_Z drops ~140 mV - a 3% shift. Designers must either limit self-heating, add compensation circuitry, or select higher-voltage Zeners with positive tempco to achieve net-zero drift in precision references.

Can BZX79-B4V7,133 be used in place of a 5.1 V Zener for improved regulation accuracy?

No - it is a 4.7 V device and cannot substitute for 5.1 V regulation without circuit redesign. While both are in the BZX79-B series, their voltage ratings differ by 0.4 V (8%), exceeding typical system tolerance budgets. Substitution would cause functional failure in feedback loops or reference-dependent comparators calibrated for 5.1 V.