onsemi SZMMBZ5243BLT1G

Overview

SZMMBZ5243BLT1G from onsemi is a 13 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 ±5% nominal Zener voltage tolerance at 9.5 mA test current, exhibits 600 Ω maximum dynamic impedance at I_ZT, and supports operation from −65 °C to +150 °C. It is used in power supply feedback loops, voltage reference circuits, and ESD-sensitive portable electronics.

For engineers reviewing the SZMMBZ5243BLT1G datasheet, pinout, applications, or equivalent options, key selection criteria include its 13 V nominal Zener voltage, 225 mW FR-5 board power rating, Class 3 (＞16 kV) HBM ESD rating, AEC-Q101 qualification, and Pb-free/RoHS-compliant SOT-23 package with cathode-indicated polarity band.

Technical Context

This device operates as a two-terminal voltage reference diode with reverse-biased Zener breakdown behavior. Its electrical characteristics are specified at 25 °C ambient with pulsed test conditions to minimize self-heating, and it features a typical temperature coefficient near zero for 13 V devices-enabling stable regulation across industrial temperature ranges.

The SOT-23 package (Case 318, Style 8) defines a fixed 3-pin configuration: Pin 1 = Anode, Pin 2 = No Connection, Pin 3 = Cathode. Thermal resistance is 556 °C/W on FR-5 board, limiting continuous dissipation to 225 mW at 25 °C with linear derating above that temperature.

Key Specifications

Pinout & Package

SOT-23 (TO-236) package, 2.90 mm × 1.30 mm × 1.00 mm body size, void-free thermosetting plastic case with corrosion-resistant finish. Cathode indicated by polarity 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 MMBZ5243BLT1G, SZMMBZ5243BLT1G adds AEC-Q101 qualification and PPAP support for automotive use, while BZX84-C13LT1G trades qualification for lower impedance and higher power-but requires separate reliability validation for mission-critical deployments.

Availability

SZMMBZ5243BLT1G is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor signal conditioning, portable medical devices, and smart home battery management systems requiring stable component supply across extended temperature and lifecycle demands.

Supply support for SZMMBZ5243BLT1G 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, medical, and IoT applications.

The MMBZ52xxBLT1G/SZMMBZ52xxBLT1G series was engineered for high-density, low-power voltage regulation in portable and automotive electronics-emphasizing small footprint, robust ESD immunity, and AEC-Q101 compliance where applicable.

FAQ

What is the nominal Zener voltage and tolerance of SZMMBZ5243BLT1G?

The SZMMBZ5243BLT1G has a nominal Zener voltage of 13 V with a guaranteed range of 12.35 V to 13.65 V at 9.5 mA test current, corresponding to ±5% tolerance. This specification is measured under pulsed conditions at 25 °C ambient and remains stable across its −65 °C to +150 °C operating temperature range, making SZMMBZ5243BLT1G suitable for precision reference and clamping applications where voltage drift must be minimized.

Is SZMMBZ5243BLT1G pin-compatible with MMBZ5243BLT1G?

Yes, SZMMBZ5243BLT1G shares identical SOT-23 pinout (Pin 1 = Anode, Pin 2 = NC, Pin 3 = Cathode) and mechanical dimensions with MMBZ5243BLT1G. Both use the same marking layout and polarity band orientation. However, SZMMBZ5243BLT1G adds automotive-specific process controls, AEC-Q101 qualification, and PPAP documentation-while electrically and physically interchangeable in most layouts, SZMMBZ5243BLT1G is the required choice for automotive production releases.

What is the maximum power dissipation of SZMMBZ5243BLT1G on standard PCB material?

SZMMBZ5243BLT1G is rated for 225 mW total power dissipation on FR-5 board at 25 °C ambient, derating linearly by 1.8 mW/°C above that temperature. On alumina substrate, it supports up to 300 mW at 25 °C. These ratings assume no additional copper pour or thermal vias; actual dissipation must be verified using thermal simulation or empirical testing when SZMMBZ5243BLT1G operates continuously near its thermal limits.

Does SZMMBZ5243BLT1G meet automotive reliability standards?

Yes, SZMMBZ5243BLT1G is AEC-Q101 qualified and PPAP capable-validated for temperature cycling, high-temperature operating life, unbiased high-humidity bias, and mechanical shock. The "SZ" prefix denotes dedicated automotive process flow and traceability controls. This makes SZMMBZ5243BLT1G appropriate for body electronics, infotainment power supplies, and other non-safety-critical automotive subsystems requiring certified component reliability.

What is the ESD rating of SZMMBZ5243BLT1G and how is it tested?

SZMMBZ5243BLT1G achieves Class 3 Human Body Model (HBM) ESD rating with >16 kV withstand capability, per ANSI/ESDA/JEDEC JS-001. This rating is confirmed through standardized factory-level qualification testing and applies to both anode and cathode terminals. The robust ESD performance allows SZMMBZ5243BLT1G to serve as primary protection in exposed interfaces-reducing or eliminating need for external TVS diodes in handheld and automotive applications.