Nexperia USA Inc. BZT52-C43X

Overview

BZT52-C43X from Nexperia is a Zener voltage regulator diode in SOD123 surface-mount package, rated for 43 V nominal Zener voltage at 5 mA test current, with ±5 % tolerance, 325 Ω maximum differential resistance, and 590 mW total power dissipation. It provides stable reference voltage in low-power biasing and overvoltage protection circuits for industrial sensor interfaces.

For engineers reviewing the BZT52-C43X datasheet, BZT52-C43X pinout, BZT52-C43X application, or BZT52-C43X equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (210 K/W junction-to-solder-point), reverse current at 38.7 V (≤0.05 μA), temperature coefficient (±0.05 mV/K), and SOD123 footprint compatibility with automated PCB assembly.

Technical Context

This device operates as a two-terminal shunt voltage regulator, maintaining a stable 43 V output across its cathode–anode terminals when reverse-biased above its breakdown threshold. Its low differential resistance (325 Ω max) ensures minimal voltage drift under load variation, while the ±5 % tolerance supports cost-sensitive non-precision regulation tasks.

The SOD123 package enables compact placement on FR4 PCBs with single-sided copper, delivering 210 K/W junction-to-solder-point thermal resistance and supporting continuous operation up to 150 °C junction temperature. Reverse leakage remains ≤0.05 μA at VR = 38.7 V, enabling low-quiescent-current standby functions.

Key Specifications

Pinout & Package

The BZT52-C43X uses the SOD123 surface-mount plastic package (2.80 mm × 1.70 mm × 1.30 mm), with cathode marked by a band on the body. Mounting requires reflow soldering only, using the standardized footprint per Figure 12 (pad length 3.27 mm, width 1.11 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZT52-C43X, BZT52-B43 offers tighter tolerance and lower impedance for precision biasing, while MMBZ5243B trades thermal performance for smaller size-making BZT52-C43X optimal for cost-effective, thermally robust 43 V regulation in industrial PCBs.

Availability

BZT52-C43X is available at Aetrix Electronics and suitable for industrial sensor biasing, power supply overvoltage clamping, and low-power reference generation requiring stable component supply and full traceability.

Supply support for BZT52-C43X 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 semiconductor manufacturer headquartered in Nijmegen, Netherlands, specializing in high-volume logic, discrete, and MOSFET solutions with automotive-grade reliability and industrial scalability.

The BZT52 series belongs to Nexperia's general-purpose Zener diode product line, designed specifically for cost-sensitive, surface-mount voltage regulation and protection in industrial, consumer, and computing applications-not qualified for automotive use.

FAQ

What is the maximum reverse voltage (V_R) that BZT52-C43X can block before breakdown?

The BZT52-C43X begins regulating at its nominal Zener voltage of 43 V, with guaranteed breakdown occurring between 40.0 V and 46.0 V at 2 mA test current. Its absolute maximum non-repetitive reverse voltage is limited by the 40 W pulse rating at 100 μs, corresponding to ~63 V for a 1 A surge. Continuous blocking above 46 V is not specified and risks irreversible damage.

Can BZT52-C43X be used in parallel for higher power dissipation?

No-Zener diodes exhibit negative temperature coefficients and manufacturing variations that cause current hogging when paralleled. Even matched units will not share current evenly, leading to thermal runaway in one device. For higher power, use a single higher-rated Zener or add an external series resistor to limit total current to ≤590 mW.

Is BZT52-C43X suitable for automotive applications?

No-this part is explicitly designated as non-automotive qualified per Nexperia's revision history (v.2, October 2025). It lacks AEC-Q101 qualification, automotive-grade screening, and extended temperature validation. For automotive use, select the -Q qualified variants such as BZT52-C43X-Q, which undergo additional stress testing and lot traceability.

How does the SOD123 package affect thermal performance compared to DO-35 or SOD-123W?

The standard SOD123 package delivers 210 K/W junction-to-solder-point thermal resistance due to its small copper pad area (1 cm² cathode pad). This is 30 % higher than SOD-123W (150 K/W) and significantly worse than axial DO-35 (≈100 K/W). Layout must allocate ≥1 cm² copper pour on the cathode pad and avoid thermal isolation to achieve rated 590 mW dissipation.