Nexperia USA Inc. PDZ3.9BF

Overview

PDZ3.9BF from Nexperia is a single low-power Zener diode designed for precision voltage regulation in space-constrained SMD applications, with a nominal Zener voltage of 3.9 V (min 3.89 V, max 4.16 V at I_Z = 5 mA), ±2 % tolerance, 90 Ω typical differential resistance at 5 mA, and 3 μA maximum reverse leakage at 1 V. It operates in general-purpose regulator circuits requiring stable reference voltages under low-current conditions.

For engineers reviewing the PDZ3.9BF datasheet, PDZ3.9BF pinout, PDZ3.9BF application, or PDZ3.9BF equivalent, this device is selected for compact voltage clamping, overvoltage protection, and biasing in portable consumer electronics, sensor signal conditioning, and low-power microcontroller power-rail supervision where thermal derating on FR4 PCBs must be considered.

Technical Context

This Zener diode functions as a two-terminal shunt voltage regulator, maintaining a stable reverse-biased breakdown voltage across its cathode–anode terminals when operated above its knee current (I_Z ≥ 0.5 mA). Its hard breakdown knee and low dynamic impedance enable accurate regulation even at low bias currents (e.g., 1 mA).

Thermal performance is defined by R_th(j-sp) = 130 K/W (junction-to-solder point) and R_th(j-a) = 340 K/W (junction-to-ambient) on standard FR4 PCB, limiting continuous power dissipation to 400 mW at T_amb ≤ 25 °C and requiring linear derating above that temperature.

Key Specifications

Pinout & Package

PDZ3.9BF is housed in a SOD323 (SC-76) surface-mount plastic package measuring 1.8 mm × 1.35 mm × 0.95 mm, with cathode indicated by a marking bar on the top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX384-B3V9 and MMSZ4685, PDZ3.9BF delivers tighter voltage control at ultra-low bias currents and superior thermal efficiency in miniaturized layouts, making it optimal for modern low-power embedded systems where size and precision outweigh raw power capacity.

Availability

PDZ3.9BF is available at Aetrix Electronics and suitable for USB interface protection, microcontroller reset supervision, low-power sensor biasing, and ADC input clamping requiring stable component supply and consistent parametric performance across production lots.

Supply support for PDZ3.9BF 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 expert focused on high-volume, high-reliability discrete, logic, and MOSFET solutions, headquartered in Nijmegen, Netherlands, serving automotive, industrial, and consumer markets.

PDZ3.9BF belongs to the PDZ-B series of low-power Zener diodes engineered specifically for compact, cost-effective voltage regulation in space-constrained consumer and industrial electronics - emphasizing tight tolerance, low leakage, and robust SMD manufacturability.

FAQ

What is the maximum continuous reverse current the PDZ3.9BF can handle without degradation?

The PDZ3.9BF is rated for a maximum continuous forward current of 200 mA, but as a Zener diode, its safe reverse operating current is determined by power dissipation limits. At 25 °C ambient on a standard FR4 PCB, it supports up to ~102 mA reverse current (400 mW ÷ 3.9 V) before exceeding P_tot; actual usable current must stay below thermal derating curves shown in Figure 1 of the datasheet.

Can PDZ3.9BF be used in place of a 3.3 V Zener for logic-level shifting?

No - PDZ3.9BF has a nominal Zener voltage of 3.9 V (3.89–4.16 V), which exceeds standard 3.3 V logic high thresholds and risks violating input voltage limits of 3.3 V CMOS devices. It is unsuitable for direct logic-level translation; a 3.3 V-rated Zener such as PDZ3.3B (3.32–3.53 V) would be appropriate instead.

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

A −2.5 mV/K coefficient means the Zener voltage decreases by approximately 2.5 mV per degree Celsius rise in junction temperature. Over a −40 °C to +125 °C range, this results in a total shift of ~413 mV (165 K × 2.5 mV/K), reducing V_Z from ~4.16 V to ~3.75 V - a critical factor in precision references requiring compensation or selection of zero-TC Zeners above 5 V.

Is the SOD323 package of PDZ3.9BF compatible with standard reflow soldering profiles?

Yes - Nexperia specifies compatibility with JEDEC J-STD-020-compliant lead-free reflow profiles. The recommended footprint (Figure 9) uses 0.6 mm wide solder lands with 0.5 mm spacing; peak temperature must not exceed 260 °C for ≤ 30 seconds, and thermal shock must remain within specified ramp rates to avoid package cracking or delamination.