onsemi SZBZX84C33LT1G

Overview

SZBZX84C33LT1G from onsemi is a 33 V, ±5% tolerance Zener diode in SOT-23 package, rated for 250 mW power dissipation on FR-5 board at 25°C, with 80 Ω dynamic impedance at 5 mA test current and 55 μA maximum reverse leakage at 24.8 V. It serves as a precision voltage reference or overvoltage clamp in low-power portable electronics.

For engineers reviewing the SZBZX84C33LT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal coefficient (±23.1 mV/°C), junction-to-ambient thermal resistance (500 °C/W), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This device operates as a two-terminal voltage-regulating diode with cathode-anode polarity, designed for stable reverse-biased breakdown at nominal 33 V. Its SOT-23 package features pin 1 (anode), pin 2 (no connection), and pin 3 (cathode), enabling compact placement on high-density PCBs.

The SZBZX84C33LT1G exhibits a temperature coefficient of +23.1 mV/°C at 5 mA, indicating positive drift with rising temperature, and maintains ≤55 μA reverse leakage at VR = 24.8 V - critical for low-quiescent-current bias networks and voltage-sense circuits.

Key Specifications

Pinout & Package

SOT-23 (TO-236) surface-mount plastic package, 2.90 mm × 1.30 mm × 1.00 mm body size, void-free thermosetting case with corrosion-resistant finish, UL 94 V-0 flammability rating, and cathode indicated by band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84C33LT1G and SZBZX84C36LT1G, the SZBZX84C33LT1G uniquely combines automotive qualification, 33 V regulation, and 23.1 mV/°C thermal stability - making it optimal for safety-critical voltage references where traceability and temperature predictability are mandatory.

Availability

SZBZX84C33LT1G is available at Aetrix Electronics and suitable for automotive ECUs, portable medical monitors, and industrial sensor nodes requiring stable component supply with full lifecycle support and AEC-Q101 documentation.

Supply support for SZBZX84C33LT1G 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

onsemi is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, and consumer markets.

The SZBZX84CxxxLT1G series belongs to onsemi's automotive-qualified Zener regulator portfolio, engineered specifically for voltage reference, overvoltage protection, and bias stabilization in harsh-environment electronic control units.

FAQ

What is the exact Zener voltage range for SZBZX84C33LT1G at 5 mA test current?

The SZBZX84C33LT1G has a guaranteed Zener voltage range of 31.0 V to 35.0 V when tested at I_ZT = 5 mA and T_A = 25°C. This ±5% tolerance is specified in the Electrical Characteristics table on page 3 of the official onsemi datasheet (Rev. 23, August 2021). The nominal 33 V value represents the center of this band, and the device maintains this specification across its qualified automotive temperature range.

Is SZBZX84C33LT1G pin-compatible with standard BZX84C33LT1G?

Yes, SZBZX84C33LT1G shares identical SOT-23 pinout (pin 1: anode, pin 2: no connection, pin 3: cathode), mechanical dimensions, and soldering profile with BZX84C33LT1G. The SZ prefix denotes automotive qualification (AEC-Q101, PPAP-capable) and unique site/control change tracking - not a physical or electrical variant. No PCB layout changes are required when upgrading from commercial to automotive grade.

What is the maximum reverse leakage current for SZBZX84C33LT1G and at what voltage is it measured?

The maximum reverse leakage current for SZBZX84C33LT1G is 55 μA, measured at V_R = 24.8 V (75% of nominal V_Z) and T_A = 25°C. This parameter appears in the "Max Reverse Leakage Current" column of the BZX84CxxxLT1 series table on page 3 of the onsemi datasheet. It reflects worst-case off-state conduction in voltage-reference or clamping configurations.

Does SZBZX84C33LT1G support high-frequency decoupling applications?

SZBZX84C33LT1G has a maximum capacitance of 70 pF at V_R = 0 V and f = 1 MHz, making it unsuitable as a primary high-frequency decoupling element. Its primary function is DC voltage regulation or transient clamping. For RF bypass, designers should pair SZBZX84C33LT1G with dedicated ceramic capacitors (e.g., 100 nF X7R) placed in parallel to handle MHz-range noise suppression.

How does the temperature coefficient of SZBZX84C33LT1G affect circuit performance over temperature?

The SZBZX84C33LT1G has a temperature coefficient of +23.1 mV/°C at I_ZT = 5 mA, meaning its Zener voltage increases linearly with temperature. Over a −40°C to +125°C range, this results in a total shift of approximately ±3.8 V from nominal 33 V. Designers must account for this drift in precision reference applications - for example, by using compensation networks or selecting tighter-tolerance alternatives like BZX84B33LT1G if drift exceeds system error budgets.