PDZ33B,115

The PDZ33B,115 from Nexperia is a high-precision 33V zener diode in the SOD323F surface-mount package, offering ±2% voltage tolerance and 1W power dissipation for demanding voltage regulation and overvoltage protection applications. Built on advanced planar technology, this zener diode provides an exceptionally sharp avalanche breakdown characteristic with low dynamic resistance (25Ω max at 5mA), ensuring precise and stable voltage regulation even with varying load currents. The tight ±2% tolerance makes the PDZ33B suitable for precision voltage references and circuits where voltage accuracy is critical. The 1W power rating, combined with the small SOD323F package, offers an impressive power-to-size ratio for space-constrained designs. The device features low reverse leakage current (0.2µA max at 25V reverse) and excellent long-term stability, making it ideal for high-impedance sensing and monitoring circuits. Fully qualified to AEC-Q101 automotive standards with a -55°C to +150°C operating junction temperature range, the PDZ33B delivers reliable performance in harsh automotive and industrial environments. The planar construction with passivated junction ensures uniform electrical characteristics and robust reliability under thermal cycling and mechanical stress. Supplied in 7″ tape-and-reel packaging with 3,000 pieces per reel, the PDZ33B is widely used in automotive electronics, power supplies, industrial control systems, and telecommunications infrastructure for precision voltage regulation, overvoltage protection, and high-voltage sensing applications.

The PDZ33B operates as a zener diode utilizing the avalanche breakdown mechanism to provide a stable 33V reference voltage. At zener voltages above approximately 5.6V, the dominant breakdown mechanism transitions from Zener effect (quantum tunneling) to avalanche breakdown, where high electric fields accelerate charge carriers to the point that they create additional electron-hole pairs through impact ionization, causing a rapid increase in reverse current. In the breakdown region, the voltage across the diode remains relatively constant over a wide range of reverse currents — this is the fundamental principle behind zener voltage regulation. The dynamic resistance (ZZ = 25Ω max) quantifies the slope of the V-I curve in the breakdown region — lower values indicate better regulation. At 33V, the temperature coefficient is positive (voltage increases with temperature), which is typical for avalanche breakdown zener diodes. The planar fabrication process creates a precisely doped p-n junction with controlled breakdown voltage and sharp turn-on characteristics. The device is passivated with a protective oxide layer to ensure long-term stability and prevent contamination. The diode can handle non-repetitive surge currents up to 80W (10/1000µs pulse), providing robust protection against transient voltage spikes. In forward bias, the PDZ33B behaves like a standard silicon diode with approximately 1.2V forward drop at 100mA. For regulator applications, the zener is reverse-biased with a series current-limiting resistor that sets the operating current within the recommended range for optimal regulation.

Marking: The SOD323F package is marked with “B12%” where % indicates the date/batch code. The cathode side is indicated by a line or band on the corresponding end of the package. For zener regulator operation, the cathode connects to the higher potential and the anode to ground (reverse-biased). Always verify polarity from the official datasheet before assembly.

• Precision Voltage Regulation: Used as a precision 33V shunt regulator or voltage reference in power supplies, instrumentation, and test equipment where ±2% accuracy is required
• Overvoltage Protection: Provides voltage clamping for protection of sensitive circuits against overvoltage transients and load dump conditions in automotive and industrial systems
• Automotive Electronics: Deployed in automotive body control modules, sensor interfaces, and power distribution units for voltage regulation and transient protection requiring AEC-Q101 qualification
• High-Voltage Sensing: Used in voltage divider networks for high-voltage monitoring and sensing in industrial power supplies, motor drives, and renewable energy systems
• Power Supply Circuits: Serves as a voltage reference in linear regulators, switching power supplies, and DC-DC converters for output voltage setting and overvoltage protection
• Surge and ESD Protection: Provides robust transient voltage suppression and ESD clamping on signal lines and power supply inputs
• Telecommunications: Used in telecom infrastructure equipment, base stations, and networking devices for voltage regulation, protection, and line interface circuits
• Battery Management: Implements overvoltage detection, charge termination, and voltage monitoring functions in battery chargers and BMS systems