onsemi SZMMBZ5234BLT3G

Overview

SZMMBZ5234BLT3G from onsemi is a 6.2 V ±5% Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board, with 7 Ω dynamic impedance at 20 mA test current and 5 µA leakage at 4 V reverse bias - used for precision voltage reference and overvoltage protection in portable power rails.

For engineers reviewing the SZMMBZ5234BLT3G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal resistance (556 °C/W), ESD rating (>16 kV HBM), AEC-Q101 qualification, and Pb-free RoHS compliance for automotive-grade signal conditioning.

Technical Context

This device operates as a two-terminal voltage reference diode with cathode-anode polarity, designed for stable reverse-biased regulation under DC or low-frequency transient conditions. Its 6.2 V nominal Zener voltage exhibits near-zero temperature coefficient in the 5–6 V range, confirmed by typical TC curves in the datasheet.

The SOT-23 package supports automated placement and reflow soldering at 260 °C for 10 seconds, with void-free thermoset plastic case and UL 94 V-0 flammability rating. Pin 2 is internally unconnected - critical for layout verification to avoid unintended shorts or routing errors.

Key Specifications

Pinout & Package

SOT-23 (TO-236) package, 2.90 × 1.30 × 1.00 mm, with cathode band marking on terminal 3. Pin 2 is No Connection (NC) - must remain unconnected in PCB layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5234BLT3G and SZMMBZ5235BLT3G, the SZMMBZ5234BLT3G uniquely delivers AEC-Q101 compliance at 6.2 V with validated automotive process controls - making it the only option for safety-critical 6.2 V clamping in ASIL-B systems without additional qualification effort.

Availability

SZMMBZ5234BLT3G is available at Aetrix Electronics and suitable for automotive sensor interfaces, USB-C power delivery clamps, and industrial IoT node power rails requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SZMMBZ5234BLT3G 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The MMBZ52xxBLT1G/SZMMBZ52xxBLT1G series was developed to deliver high-reliability, surface-mount Zener regulation for space-constrained and thermally demanding applications - especially where AEC-Q101 qualification and high ESD immunity are mandatory.

FAQ

What is the exact Zener voltage tolerance of SZMMBZ5234BLT3G?

The SZMMBZ5234BLT3G has a specified Zener voltage range of 5.89 V (min) to 6.51 V (max) at test current I_ZT = 20 mA, corresponding to a ±5% tolerance around the nominal 6.2 V value. This tolerance is guaranteed across the full operating temperature range of −65 °C to +150 °C and is verified per onsemi's AEC-Q101 stress testing protocol for SZMMBZ5234BLT3G.

Is SZMMBZ5234BLT3G pin-compatible with MMBZ5234BLT3G?

Yes, SZMMBZ5234BLT3G and MMBZ5234BLT3G share identical SOT-23 pinout (Pin 1: Anode, Pin 2: NC, Pin 3: Cathode), mechanical dimensions, and thermal characteristics. However, SZMMBZ5234BLT3G includes automotive-specific process controls, AEC-Q101 qualification, and PPAP documentation - features absent in the commercial-grade MMBZ5234BLT3G variant.

What is the maximum allowable junction temperature for SZMMBZ5234BLT3G?

The SZMMBZ5234BLT3G has a maximum junction temperature (T_J) of +150 °C, with storage temperature matching that range (−65 °C to +150 °C). At ambient temperatures above 25 °C, power dissipation must be linearly derated at 1.8 mW/°C on FR-5 board - meaning at 85 °C ambient, maximum safe P_D drops to 117 mW for reliable long-term operation of SZMMBZ5234BLT3G.

Does SZMMBZ5234BLT3G require external current limiting in shunt regulator applications?

Yes, SZMMBZ5234BLT3G requires an external series resistor to limit Zener current within its 225 mW power rating and prevent thermal runaway. For example, when regulating a 12 V supply to 6.2 V with 20 mA test current, a minimum 290 Ω resistor is needed - calculated as (12 V − 6.2 V)/20 mA. This design constraint applies identically to all operating conditions of SZMMBZ5234BLT3G.

How does the ESD rating of SZMMBZ5234BLT3G impact PCB layout decisions?

The SZMMBZ5234BLT3G's Class 3 HBM ESD rating (>16 kV) allows direct placement on exposed I/O traces without supplemental TVS diodes in most handheld and automotive interface applications. However, layout must still maintain ≥0.2 mm clearance to adjacent conductors and avoid routing Pin 2 (NC) to any net - ensuring the high-ESD robustness of SZMMBZ5234BLT3G is not compromised by parasitic coupling or solder bridging.