onsemi MMBZ5228ELT1

Overview

MMBZ5228ELT1 from onsemi is a 3.9 V, 225 mW surface-mount Zener diode in SOT-23 package, designed for precision voltage regulation and overvoltage protection in space-constrained circuits. It delivers 3.70–4.10 V nominal Zener voltage at 20 mA test current, with 23 Ω dynamic impedance and ≤0.25 µA leakage at 1 V reverse bias. It is used in voltage reference circuits for portable power management in hand-held devices.

For engineers reviewing the MMBZ5228ELT1 datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance (±5.1%), low dynamic impedance at I_ZT, ESD robustness (>16 kV HBM), thermal resistance (556 °C/W on FR-5), and Pb-free SOT-23 packaging compatibility with automated assembly.

Technical Context

This device operates as a two-terminal voltage reference diode with cathode-anode polarity and no internal connection on pin 2. Its Zener breakdown mechanism provides stable reverse conduction at 3.9 V with minimal temperature drift - typical TC near 0 mV/°C for this voltage range per Figure 1.

It supports pulse operation up to 225 W (8 × 20 µs) and continuous dissipation of 225 mW on FR-5 board, derating linearly above 25°C at 1.8 mW/°C. Junction temperature range spans −65°C to +150°C, enabling use in industrial and automotive ambient environments.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with void-free thermosetting case, corrosion-resistant finish, and UL 94 V-0 flammability rating. Cathode indicated by 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 regulation applications.

Compared with BZX84-C3V9 and MMBZ5228BS, the MMBZ5228ELT1 offers optimal balance of regulation accuracy (23 Ω Z_ZT), ESD hardness (>16 kV), and SOT-23 footprint - making it preferred for miniaturized, battery-operated systems where voltage reference fidelity and layout density are jointly constrained.

Availability

MMBZ5228ELT1 is available at Aetrix Electronics and suitable for portable power monitoring, USB interface clamp, and low-power MCU reset circuits requiring stable component supply and RoHS-compliant sourcing.

Supply support for MMBZ5228ELT1 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 MMBZ52xxELT1G series was engineered for space-constrained voltage regulation and ESD protection in portable electronics - emphasizing low-profile SOT-23 packaging, high-reliability Zener performance, and full AEC-Q101 qualification readiness.

FAQ

What is the Zener voltage tolerance of MMBZ5228ELT1?

The MMBZ5228ELT1 has a Zener voltage range of 3.70 V to 4.10 V at 20 mA test current, corresponding to a ±5.1% tolerance around the nominal 3.9 V value. This tolerance is guaranteed across the full operating temperature range and reflects manufacturing process control, not drift - actual unit-to-unit variation remains within this band under specified test conditions.

Does MMBZ5228ELT1 have a built-in capacitor or integrated ESD structure?

No, the MMBZ5228ELT1 is a discrete silicon Zener diode with no integrated capacitor or additional ESD structures beyond its inherent junction characteristics. Its >16 kV HBM ESD rating arises from optimized doping and passivation in the SOT-23 die, not added components. Capacitance is 10–15 pF at 0 V bias (per Figure 5), typical for a 3.9 V Zener junction.

Can MMBZ5228ELT1 be used in place of MMBZ5228BLT1?

No - MMBZ5228ELT1 and MMBZ5228BLT1 differ in Zener voltage specification: the "E" suffix denotes tighter 3.70–4.10 V tolerance (±5.1%), while "B" indicates wider 3.5–4.3 V (±10.3%). They share identical package, power rating, and pinout, but substituting them requires verification that system regulation margins accommodate the looser tolerance of the "B" variant.

What is the maximum continuous current MMBZ5228ELT1 can handle at 85°C ambient?

At T_A = 85°C, the MMBZ5228ELT1's power dissipation is derated to 225 mW − (85 − 25) × 1.8 mW/°C = 117 mW. With V_Z ≈ 3.9 V, maximum continuous Zener current is ~30 mA. Exceeding this risks thermal runaway due to rising R_JA and reduced heat transfer at elevated ambient temperatures.

Is MMBZ5228ELT1 qualified for automotive applications?

The MMBZ5228ELT1 itself is not AEC-Q101 qualified; however, the SZMMBZ5228ELT1G variant (same electrical specs, "SZ" prefix) is fully AEC-Q101 qualified and PPAP capable. For automotive designs, engineers must specify the SZ-prefixed part - the "MMBZ" version is intended for industrial and consumer applications where full automotive qualification is not required.