onsemi BZX84C22ET1

Overview

BZX84C22ET1 from onsemi is a 22 V, 225 mW surface-mount Zener diode in SOT-23 package, rated for 5 mA test current with 20.8–23.3 V breakdown range, 55 Ω dynamic impedance at 5 mA, and −65 °C to +150 °C operating temperature. It provides precision voltage regulation in space-constrained power supply rails and reference circuits for portable electronics.

For engineers reviewing the BZX84C22ET1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, cathode-anode polarity mapping, ESD robustness (Class 3, >16 kV HBM), and direct alternatives for voltage reference design validation.

Technical Context

The BZX84C22ET1 operates as a two-terminal voltage reference device, conducting in reverse bias above its nominal Zener voltage (22 V) with tightly controlled tolerance (±5 % at 5 mA). Its 55 Ω Zener impedance at IZT = 5 mA ensures stable regulation under moderate load transients.

Thermal resistance is 556 °C/W on FR-5 board and 417 °C/W on alumina substrate, enabling predictable power derating above 25 °C. The device features no internal connection on pin 2, confirmed cathode marking via band, and Pb-free SOT-23 packaging compliant with AEC-Q101 for automotive-grade reliability.

Key Specifications

Pinout & Package

SOT-23 (Case 318, Style 8) surface-mount package with 3 terminals: pin 1 = anode, pin 2 = no connection (NC), pin 3 = cathode. Cathode identified by molded band; maximum soldering temperature 260 °C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84C22ET1, MMBZ5266BLT1 offers lower impedance at higher current but lacks AEC-Q101 validation, while BZX84-C22LT1G provides identical voltage spec with improved thermal headroom and updated automotive qualification-making it suitable for next-generation ECUs where long-term reliability under thermal stress is critical.

Availability

BZX84C22ET1 is available at Aetrix Electronics and suitable for portable electronics, automotive body control modules, and industrial sensor interfaces requiring stable component supply with full traceability and lifecycle continuity.

Supply support for BZX84C22ET1 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and consumer markets.

The BZX84C22ET1 belongs to the BZX84CxxxET1 series of low-power Zener regulators designed specifically for space-constrained voltage reference and overvoltage protection in portable and automotive electronics.

FAQ

What is the Zener voltage tolerance of the BZX84C22ET1 at 5 mA test current?

The BZX84C22ET1 has a Zener voltage range of 20.8 V to 23.3 V at I_ZT = 5 mA, corresponding to a ±5 % tolerance around the nominal 22 V rating. This tolerance is guaranteed across the full operating temperature range of −65 °C to +150 °C and is measured using pulse testing to avoid self-heating effects. The BZX84C22ET1 datasheet specifies these limits in Table 1 on page 3.

Does the BZX84C22ET1 have a functional connection on pin 2?

No, pin 2 of the BZX84C22ET1 is internally not connected (NC) and must remain unconnected on the PCB. The device uses only pins 1 (anode) and 3 (cathode) for operation. This is explicitly stated in the Pinout section on page 2 of the official onsemi datasheet and confirmed in the mechanical drawings on page 6. Leaving pin 2 floating avoids unintended parasitic coupling.

How does the BZX84C22ET1's temperature coefficient affect its regulation accuracy over temperature?

The BZX84C22ET1 exhibits a +15.4 mV/°C temperature coefficient at I_ZT = 5 mA, meaning its Zener voltage increases linearly with junction temperature. Over a −40 °C to +125 °C ambient range, this results in approximately ±2.5 V drift. For high-accuracy applications, designers must compensate using thermistor networks or select complementary TC components. The BZX84C22ET1's TC is documented in Table 1 and Figure 1 of the datasheet.

Can the BZX84C22ET1 be used in automotive applications?

Yes, the BZX84C22ET1 is AEC-Q101 qualified and PPAP capable, making it suitable for automotive body electronics such as door modules, lighting controllers, and infotainment power rails. Its −65 °C to +150 °C junction temperature range, Class 3 ESD rating, and Pb-free SOT-23 package meet key automotive reliability requirements. The BZX84C22ET1's qualification status is stated in the Specification Features section on page 1 of the datasheet.

What is the maximum reverse leakage current for the BZX84C22ET1 at 17.6 V?

The BZX84C22ET1 specifies a maximum reverse leakage current of 50 nA at V_R = 17.6 V (80 % of nominal 22 V), tested at T_A = 25 °C. This low leakage minimizes quiescent current draw in battery-powered systems and ensures stable reference behavior in high-impedance divider networks. The value is listed in the Electrical Characteristics table on page 3 under "Max Reverse Leakage Current" for the BZX84C22ET1 row.