Nexperia USA Inc. BZX79-C33,113

Overview

BZX79-C33,113 from Nexperia is a ±5% tolerance Zener voltage regulator diode with nominal 33 V breakdown voltage at 2 mA test current, 75 Ω typical differential resistance, and −23.3 mV/K temperature coefficient. It operates as a low-power voltage reference in bias networks, overvoltage clamping circuits, and analog signal conditioning stages where stable 33 V regulation under ≤400 mW dissipation is required.

For engineers reviewing the BZX79-C33,113 datasheet, BZX79-C33,113 pinout, BZX79-C33,113 application, or BZX79-C33,113 equivalent, this part serves as a cost-optimized, through-hole Zener for precision reference and protection functions in industrial power supplies, sensor interface circuits, and legacy analog instrumentation requiring DO-35 package compatibility and 33 V stabilization.

Technical Context

This device functions as a reverse-biased silicon Zener diode operating in avalanche breakdown mode. Its 33 V nominal Zener voltage is specified at I_Ztest = 2 mA, with a typical differential resistance of 75 Ω and a negative temperature coefficient of −23.3 mV/K - indicating decreasing Zener voltage with rising junction temperature.

The SOD27 (DO-35) hermetically sealed glass package enables reliable operation up to +200 °C storage temperature and supports non-repetitive peak reverse power dissipation of 40 W for 100 μs pulses. Thermal resistance from junction to ambient is 380 K/W under standard PCB mounting conditions.

Key Specifications

Pinout & Package

Hermetically sealed axial-leaded SOD27 (DO-35) glass package with cathode band marking; leads are tinned copper alloy, compatible with wave and hand soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4747A, BZX79-C33,113 offers smaller DO-35 footprint and lower r_dif, but reduced power handling; versus BZX79-B33,113, it trades 3% tighter tolerance and 25 Ω lower impedance for lower unit cost in non-critical reference roles.

Availability

BZX79-C33,113 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface circuits, legacy test equipment, and automotive body control modules requiring stable component supply with long-lifecycle support.

Supply support for BZX79-C33,113 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.

This device belongs to the BZX79 series of low-power Zener diodes designed for voltage regulation and reference applications in cost-sensitive, space-constrained through-hole designs.

FAQ

What is the maximum continuous power dissipation for BZX79-C33,113 at 50 °C ambient?

The maximum continuous power dissipation is 500 mW when mounted on a PCB without metallization pad and with lead length ≤8 mm at T_amb = 50 °C. At higher ambient temperatures, derating applies per the thermal resistance of 380 K/W - for example, at 70 °C ambient, max power drops to approximately 370 mW.

How does the temperature coefficient affect regulation accuracy over temperature?

The specified temperature coefficient of −23.3 mV/K means the Zener voltage decreases by ~23.3 mV per Kelvin rise in junction temperature. Over a 100 K range (e.g., −25 °C to +75 °C), this results in ~2.3 V total drift - a key factor when designing for wide-temperature stability without compensation.

Can BZX79-C33,113 be used as a replacement for BZX79-B33,113 in existing designs?

Yes, electrically and mechanically - both share identical SOD27 package, pinout, and absolute maximum ratings. The primary difference is tolerance: ±5% vs ±2%. If the original design accommodates 5% variation in reference voltage, substitution is valid without layout change.

What is the reverse leakage current at 23.1 V (70% of nominal V_Z)?

At V_R = 23.1 V (70% of 33 V), the maximum reverse leakage current is 50 nA, as specified in Table 2 for types BZX79-B/C33. This low leakage ensures minimal error contribution in high-impedance reference divider networks.