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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

onsemi MMSZ15T3G

Name: MMSZ15T3G
Brand: onsemi
SKU: MMSZ15T3G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ15T3G

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ15T3G.pdf

Description:: DIODE ZENER 15V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:3,992

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Product details

Overview

MMSZ15T3G from onsemi is a 15 V, ±5% tolerance Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C on FR−5 board, with 30 Ω maximum dynamic impedance at 5 mA and 0.05 μA reverse leakage at 10.5 V, used for precision voltage reference and overvoltage protection in power supply rails.

For engineers reviewing the MMSZ15T3G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, cathode/anode terminal mapping, automotive-grade AEC−Q101 qualification status, and direct alternatives with documented Zener voltage and impedance differences.

Technical Context

This device operates as a two-terminal voltage regulator in reverse-biased mode, maintaining stable 15 V output across load variations when biased at I_ZT = 5 mA. Its 30 Ω Zener impedance (ZZT) ensures low voltage deviation under dynamic current changes, and its −55°C to +150°C junction temperature range supports operation in harsh environments.

The SOD−123 package enables automated placement in high-density PCB layouts, while its Class 3 ESD rating (>16 kV HBM) provides robustness against handling-induced transients. Thermal resistance of 340°C/W (Junction-to-Ambient) defines its power derating curve above 75°C ambient.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	14.25 V min / 15 V nominal / 15.75 V max at I_ZT = 5 mA - defines regulation band for precision reference design
Power Dissipation (P_D)	500 mW at T_L = 75°C - sets maximum continuous DC power before thermal shutdown risk
Zener Impedance (Z_ZT)	≤30 Ω at I_ZT = 5 mA - determines output voltage stability under load step changes
Reverse Leakage (I_R)	≤0.05 μA at V_R = 10.5 V - ensures minimal quiescent current in standby circuits
Thermal Resistance (R_JA)	340°C/W - dictates required board copper area and airflow for safe 500 mW operation
ESD Rating	Class 3 (>16 kV HBM) - eliminates need for external ESD protection in handling-sensitive assembly lines
AEC−Q101 Qualified	Yes - validates suitability for automotive power management modules without additional qualification testing

Pinout & Package

SOD−123 surface-mount plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant finish, cathode indicated by polarity band, rated for 260°C soldering (10 s).

Pin/Terminal	Circuit Role	Design Meaning
1 (Cathode)	Zener voltage reference node	Connected to regulated output rail; voltage measured relative to anode; polarity band identifies this terminal
2 (Anode)	Reference ground/reference return	Typically tied to system ground or lower-potential node; completes reverse-bias path for Zener conduction

Key Features

Feature	Design Value
500 mW power rating on FR−5 board	Enables use in compact power supplies without heatsinking where board space limits thermal mass
±5% Zener voltage tolerance	Supports cost-effective voltage clamping in non-critical analog monitoring paths without trimming
Class 3 ESD protection (>16 kV HBM)	Reduces field failure risk during automated assembly and end-user handling in consumer electronics
AEC−Q101 qualification	Permits drop-in use in automotive body control modules and infotainment power domains without requalification
Pb−Free (RoHS-compliant) packaging	Meets global environmental compliance requirements for industrial and medical equipment shipments

Applications

Power Supply Voltage Clamp	Microcontroller I/O Protection
Use Scenario: Clamping 12 V automotive accessory rail to prevent >15 V transients from damaging downstream regulators. IC Role / Device Role / Timing Role: Two-terminal shunt regulator absorbing surge energy above 15 V threshold. Use Value: Limits transient overvoltage to ≤15.75 V (max V_Z) with <30 Ω dynamic impedance ensuring fast response to load steps.	Use Scenario: Protecting 3.3 V MCU GPIO pins from accidental 5 V misconnection or ESD events. IC Role / Device Role / Timing Role: Reverse-biased Zener placed between I/O line and ground to clamp excursions above 15 V. Use Value: Leverages 0.05 μA leakage at 10.5 V to avoid signal distortion during normal 3.3 V operation while triggering at defined threshold.
Reference Voltage Source	Overvoltage Detection Threshold
Use Scenario: Providing stable 15 V reference for ADC input scaling in industrial sensor signal conditioning. IC Role / Device Role / Timing Role: Passive voltage reference generating fixed bias point for op-amp gain stages. Use Value: ±5% tolerance and <30 Ω Z_ZT ensure reference accuracy remains within 0.75 V across temperature and current variation.	Use Scenario: Triggering comparator-based overvoltage alarm when battery voltage exceeds 15.75 V in UPS systems. IC Role / Device Role / Timing Role: Zener node feeding comparator hysteresis network to define trip threshold. Use Value: Max V_Z = 15.75 V directly sets upper detection limit; low leakage avoids false triggers during brownout conditions.

Power Supply Voltage Clamp

Microcontroller I/O Protection

Use Scenario: Clamping 12 V automotive accessory rail to prevent >15 V transients from damaging downstream regulators.

IC Role / Device Role / Timing Role: Two-terminal shunt regulator absorbing surge energy above 15 V threshold.

Use Value: Limits transient overvoltage to ≤15.75 V (max V_Z) with <30 Ω dynamic impedance ensuring fast response to load steps.

Use Scenario: Protecting 3.3 V MCU GPIO pins from accidental 5 V misconnection or ESD events.

IC Role / Device Role / Timing Role: Reverse-biased Zener placed between I/O line and ground to clamp excursions above 15 V.

Use Value: Leverages 0.05 μA leakage at 10.5 V to avoid signal distortion during normal 3.3 V operation while triggering at defined threshold.

Reference Voltage Source

Overvoltage Detection Threshold

Use Scenario: Providing stable 15 V reference for ADC input scaling in industrial sensor signal conditioning.

IC Role / Device Role / Timing Role: Passive voltage reference generating fixed bias point for op-amp gain stages.

Use Value: ±5% tolerance and <30 Ω Z_ZT ensure reference accuracy remains within 0.75 V across temperature and current variation.

Use Scenario: Triggering comparator-based overvoltage alarm when battery voltage exceeds 15.75 V in UPS systems.

IC Role / Device Role / Timing Role: Zener node feeding comparator hysteresis network to define trip threshold.

Use Value: Max V_Z = 15.75 V directly sets upper detection limit; low leakage avoids false triggers during brownout conditions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX84-C15LT1G	Same 15 V nominal Zener, but 350 mW rating and 30 Ω Z_ZT at 5 mA; SOT−23 package	Lower power handling requires derating above 70°C; smaller footprint suits ultra-dense layouts	Select when board space is constrained and peak power stays below 350 mW
MMBZ5245BT1G	15 V nominal, ±5%, but 225 mW rating and 17 Ω Z_ZT at 20 mA; SOT−23 package	Higher dynamic impedance at low current; optimized for higher bias currents than MMSZ15T3G	Select when circuit operates near 20 mA Zener current and needs tighter low-current regulation

Compared with BZX84-C15LT1G and MMBZ5245BT1G, the MMSZ15T3G offers superior 500 mW power capability and SOD−123 thermal performance-critical for sustained clamping in automotive power rails-while maintaining identical voltage tolerance and compatibility with standard pick-and-place workflows.

Availability

MMSZ15T3G is available at Aetrix Electronics and suitable for automotive power management, industrial sensor interface, and consumer electronics voltage clamping requiring stable component supply and AEC−Q101 compliance.

Supply support for MMSZ15T3G 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 (Semiconductor Components Industries, LLC) is a global supplier of energy-efficient semiconductor solutions, specializing in automotive, industrial, cloud, and IoT applications.

The MMSZxxxT1G series was designed specifically for surface-mount voltage regulation in space-constrained, thermally demanding environments-emphasizing reliability, AEC−Q101 qualification, and high-volume manufacturability in SOD−123.

FAQ

What is the Zener voltage tolerance of the MMSZ15T3G?

The MMSZ15T3G has a standard Zener voltage tolerance of ±5% at 25°C, resulting in a guaranteed operating range of 14.25 V to 15.75 V when tested at I_ZT = 5 mA. This tolerance remains valid across the full −55°C to +150°C junction temperature range per onsemi's characterization data, making it suitable for designs requiring predictable clamping without calibration.

Does the MMSZ15T3G require a current-limiting resistor in series?

Yes, the MMSZ15T3G must be used with an external series current-limiting resistor to control Zener current and prevent thermal runaway. For example, at 24 V input and target I_Z = 5 mA, a 1.8 kΩ resistor limits power dissipation to 45 mW in the resistor and keeps MMSZ15T3G within its 500 mW rating. The resistor value is calculated using (V_IN − V_Z) / I_Z, with margin for worst-case V_Z and temperature drift.

Is the MMSZ15T3G suitable for automotive applications?

Yes, the MMSZ15T3G is AEC−Q101 qualified and PPAP capable, confirming its suitability for automotive applications including body control modules, lighting drivers, and infotainment power domains. Its −55°C to +150°C operating range, 16 kV HBM ESD rating, and Pb−Free construction meet automotive reliability and compliance requirements without additional qualification.

What is the maximum reverse leakage current for the MMSZ15T3G?

The maximum reverse leakage current for the MMSZ15T3G is 0.05 μA at V_R = 10.5 V and T_A = 25°C. This ultra-low leakage ensures minimal loading on sensitive reference nodes and prevents unintended discharge in battery-backed circuits, especially critical in always-on monitoring systems where quiescent current must remain sub-100 nA.

How does the thermal derating of the MMSZ15T3G work above 75°C?

The MMSZ15T3G derates linearly at 6.7 mW/°C above 75°C ambient (T_L), based on its 500 mW rating at 75°C. At 100°C, maximum allowable power drops to 332.5 mW (500 − (100 − 75) × 6.7). This derating follows the R_JA = 340°C/W thermal resistance and must be applied in PCB layout decisions-such as copper pour area and airflow-to avoid exceeding 150°C junction temperature.

MMSZ15T3G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 15 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 30 Ohms

Current - Reverse Leakage @ Vr:: 50 nA @ 10.5 V

Voltage - Forward (Vf) (Max) @ If:: 900 mV @ 10 mA

Operating Temperature:: -55°C ~ 150°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOD-123

MMSZ15T3G FAQ

1.How can I place an order for MMSZ15T3G through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ15T3G on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MMSZ15T3G reliable?

The price and inventory of MMSZ15T3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ15T3G is usually 5 days.

3.What payment methods are accepted for MMSZ15T3G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ15T3G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ15T3G?

MMSZ15T3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ15T3G order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MMSZ15T3G?

For technical support, including MMSZ15T3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ15T3G requirements.

6.How does Aetrix verify that MMSZ15T3G is sourced from the original manufacturer or authorized distributors?

All MMSZ15T3G products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MMSZ15T3G meets industry standards.

7.What is the process for return or replacement of MMSZ15T3G?

All MMSZ15T3G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ15T3G, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MMSZ15T3G part is unused and in its original packaging.

Return procedure for MMSZ15T3G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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