onsemi SZBZX84C27ET3G

Overview

SZBZX84C27ET3G from onsemi is a 27 V, 250 mW Zener diode in SOT-23 package, designed for precision voltage regulation and transient suppression in space-constrained circuits. It delivers nominal Zener voltage of 27 V at 5 mA test current, with dynamic impedance ≤80 Ω, ±5% tolerance, and temperature coefficient of +18.9 mV/°C - suitable for power supply reference and overvoltage protection in portable electronics.

For engineers reviewing the SZBZX84C27ET3G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage accuracy at 5 mA, low leakage (<50 nA at 20.3 V), thermal stability across −65°C to +150°C, ESD robustness (>16 kV HBM), and compatibility with automated SMT assembly on FR-5 boards.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to clamp voltage at its rated Zener level. Its SOT-23 package features Pin 1 (Anode), Pin 2 (No Connection), and Pin 3 (Cathode), with polarity indicated by a cathode band.

The SZBZX84C27ET3G exhibits a positive temperature coefficient (+18.9 mV/°C) above ~5 V, enabling stable regulation under thermal drift. It supports peak pulse power of 225 W (8 × 20 µs) and maintains ≤50 nA reverse leakage at VR = 20.3 V - critical for low-power standby circuits.

Key Specifications

Pinout & Package

SOT-23 (TO-236) surface-mount package: 2.90 mm × 1.30 mm × 1.00 mm body, thermoset plastic case with corrosion-resistant finish, UL 94 V-0 flammability rating, and cathode polarity band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX84C27ET3G and MMSZ4688T1G, SZBZX84C27ET3G uniquely combines AEC-Q101 qualification, SOT-23 miniaturization, and 250 mW regulation in a single automotive-grade component - making it optimal for new automotive ECUs where space, reliability, and compliance are jointly constrained.

Availability

SZBZX84C27ET3G is available at Aetrix Electronics and suitable for automotive control units, industrial sensor interfaces, and portable medical devices requiring stable component supply, long-term lifecycle assurance, and AEC-Q101-compliant sourcing.

Supply support for SZBZX84C27ET3G 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 silicon solutions for automotive, industrial, cloud, and IoT applications.

The BZX84CxxxETxG series - including SZBZX84C27ET3G - was engineered for high-density, low-power voltage regulation in space-constrained portable and automotive electronics, emphasizing AEC-Q101 reliability and automated assembly compatibility.

FAQ

What is the Zener voltage tolerance of SZBZX84C27ET3G at 5 mA test current?

The SZBZX84C27ET3G has a Zener voltage range of 25.1 V to 28.9 V at I_ZT = 5 mA, corresponding to ±7% tolerance around the nominal 27 V rating. This specification is verified per onsemi's Electrical Characteristics table on page 3 of the August 2024 datasheet revision, and applies under TA = 25°C with pulse testing to minimize self-heating effects. The SZBZX84C27ET3G maintains this tolerance across its qualified operating temperature range.

Does SZBZX84C27ET3G have a built-in capacitor or require external filtering?

No, SZBZX84C27ET3G is a discrete Zener diode with no integrated capacitance - its typical junction capacitance is 70 pF at 0 V bias and 1 MHz, as measured in the "Typical Characteristics" section (Figure 5) of the datasheet. Designers must add external RC filters or bypass capacitors if high-frequency noise rejection is required, since the SZBZX84C27ET3G itself provides only DC voltage clamping and transient suppression via its Zener action.

Can SZBZX84C27ET3G replace BZX84C27ET3G in an existing PCB layout?

Yes, SZBZX84C27ET3G is pin-to-pin compatible with BZX84C27ET3G - both use identical SOT-23 package (Style 8), same pinout (Pin 1: Anode, Pin 2: No Connection, Pin 3: Cathode), and share identical mechanical dimensions and soldering profiles. The only functional difference is the SZ prefix denoting AEC-Q101 qualification and PPAP capability; all electrical parameters match per the datasheet's "* Include SZ-prefix devices where applicable" note on page 3. No PCB changes are needed for drop-in replacement.

What is the maximum reverse leakage current for SZBZX84C27ET3G at 20.3 V?

The maximum reverse leakage current for SZBZX84C27ET3G is 50 nA at V_R = 20.3 V and T_A = 25°C, as specified in the "ELECTRICAL CHARACTERISTICS" table on page 3 of the datasheet. This value is guaranteed across the full operating temperature range up to +150°C junction temperature, supporting ultra-low-power applications such as battery-backed real-time clocks or always-on sensor wake-up circuits where standby current must remain sub-100 nA.

Is SZBZX84C27ET3G suitable for use in high-reliability automotive power domains?

Yes, SZBZX84C27ET3G is explicitly qualified to AEC-Q101 standards and PPAP capable, making it suitable for automotive power domains including body control modules, ADAS sensor supplies, and infotainment voltage references. Its −65°C to +150°C junction temperature range, 16 kV HBM ESD rating, and validated performance under thermal cycling and humidity testing meet automotive reliability requirements - unlike non-SZ variants such as BZX84C27ET3G which lack formal qualification.