Nexperia USA Inc. PZU84-C33R

Overview

PZU84-C33R from Nexperia is a ±5 % tolerance Zener voltage regulator diode with nominal 33 V breakdown voltage, 250 mW power rating, and SOT23 surface-mount package-designed for precision voltage reference and overvoltage protection in low-power analog circuits, such as sensor biasing and ADC reference stabilization.

For engineers reviewing the PZU84-C33R datasheet, PZU84-C33R pinout, PZU84-C33R application, or PZU84-C33R equivalent, key selection criteria include Zener voltage tolerance (±5 %), differential resistance (250 Ω at I_Z = 5 mA), temperature coefficient (+27.4 mV/K), reverse leakage (<0.05 μA at V_R = 25 V), and thermal resistance (330 K/W junction-to-solder-point).

Technical Context

This Zener diode operates in reverse-bias breakdown mode to maintain stable voltage across its terminals under varying load and temperature conditions. Its hard breakdown knee and low dynamic impedance at 5 mA enable accurate regulation in low-current reference paths.

The device features two distinct performance variants: the C-series (e.g., PZU84-C33R) prioritizes low leakage and tight voltage tolerance, while B-series parts trade slight leakage increase for optimized switching noise suppression per AN90031.

Key Specifications

Pinout & Package

Supplied in SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch), with three terminals: anode (Pin 1), not connected (Pin 2), and cathode (Pin 3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PZU84-C33R, BZX84-C33 offers lower cost but sacrifices 30 % tighter differential resistance and 20× lower leakage; MMSZ5257ET1G matches voltage range but introduces 20× higher leakage and reduced thermal performance-making PZU84-C33R optimal for precision analog reference and low-power clamp designs.

Availability

PZU84-C33R is available at Aetrix Electronics and suitable for industrial sensor biasing, ADC reference stabilization, and overvoltage clamp protection requiring stable component supply, consistent parametric performance across production lots, and long-term obsolescence management.

Supply support for PZU84-C33R 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 delivering high-performance, reliable discrete, logic, and MOSFET devices with focus on efficiency, miniaturization, and robustness for industrial and automotive markets.

The PZU84 series belongs to Nexperia's general-purpose Zener regulator portfolio, engineered specifically for stable voltage reference and protection functions in space-constrained, thermally demanding SMT applications.

FAQ

What is the maximum continuous reverse current the PZU84-C33R can sustain without exceeding its 250 mW power limit?

At 25 °C ambient and mounted on standard FR4 PCB, the PZU84-C33R sustains up to 7.6 mA continuous reverse current (250 mW ÷ 33 V ≈ 7.6 mA) before reaching thermal derating thresholds. Derating begins linearly above 25 °C at 2.0 mW/°C based on R_th(j-a) = 500 K/W, limiting usable current to ~5.5 mA at 85 °C ambient.

How does the "not connected" pin (Pin 2) affect PCB layout and thermal design?

Pin 2 is internally unconnected and must remain electrically isolated-no copper pour, trace, or thermal relief should contact it. Including it in ground planes or thermal pads increases parasitic capacitance and risks mechanical stress cracking during reflow. The recommended footprint (Fig. 10) specifies 0.6 mm solder land width and 0.5 mm spacing to ensure isolation.

Can PZU84-C33R be used in series or parallel configurations for higher voltage or current capability?

No-series connection causes mismatched Zener voltages due to process variation, leading to uneven voltage distribution and potential failure. Parallel use is prohibited because minor V_Z differences cause current hogging; the lowest-V_Z unit carries >90 % of total current, exceeding its 200 mA absolute maximum forward current rating.

What is the significance of the +27.4 mV/K temperature coefficient for circuit stability?

A positive 27.4 mV/K coefficient means the Zener voltage rises ~0.9 V over a 33 °C junction temperature increase (e.g., from 25 °C to 58 °C). In closed-loop systems, this drift must be compensated-either via complementary NTC bias networks or digital calibration-to maintain <±0.05 % reference stability across operating temperature ranges.