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

onsemi MMSZ12T1

Name: MMSZ12T1
Brand: onsemi
SKU: MMSZ12T1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ12T1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ12T1.pdf

Description:: DIODE ZENER 12V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:5,573

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Product details

Overview

MMSZ12T1 from onsemi is a 500 mW, ±5% tolerance Zener diode in SOD−123 package, rated for 12 V nominal reverse breakdown at 5 mA test current (V_Z = 11.4–12.6 V), with dynamic impedance of 25 Ω and reverse leakage ≤0.1 μA at 9.6 V, used for precision voltage regulation and overvoltage protection in low-power analog and power management circuits.

For engineers reviewing the MMSZ12T1 datasheet, pinout, applications, or equivalent options, this device serves as a surface-mount voltage reference with AEC−Q101 qualification, ESD robustness (>16 kV HBM), and thermal stability across −55°C to +150°C - critical for automotive body electronics, industrial sensor interfaces, and portable power rail clamping.

Technical Context

This Zener diode operates in reverse-bias breakdown mode with a specified test current of 5 mA (I_ZT = 5 mA) and exhibits a temperature coefficient of approximately +2.2 mV/°C near 12 V, enabling stable reference performance under varying ambient conditions. Its junction-to-ambient thermal resistance is 340°C/W on FR−5 board, limiting continuous power dissipation to 500 mW at T_L = 75°C.

The device features a cathode-indicated polarity band, Pb−free SOD−123 plastic package (1.60 × 2.69 × 1.16 mm), and UL 94 V−0 flammability rating. It delivers <0.1 μA reverse leakage at VR = 9.6 V and maintains forward voltage ≤0.95 V at I_F = 10 mA.

Key Specifications

Parameter	Value and Actual Design Meaning
Nominal Zener Voltage	12 V (range 11.4–12.6 V at I_ZT = 5 mA; ±5% tolerance enables predictable clamping in 12 V rail monitoring)
Power Dissipation	500 mW on FR−5 board (supports sustained regulation in compact PCB layouts without forced cooling)
Zener Impedance	25 Ω at I_ZT = 5 mA (low dynamic impedance ensures minimal output voltage variation under load transients)
Reverse Leakage	≤0.1 μA at V_R = 9.6 V (ultra-low leakage preserves battery life in always-on sensing nodes)
ESD Rating	Class 3 (>16 kV HBM) (robust handling during automated assembly and field operation)
Operating Temperature	−55°C to +150°C (validates use in under-hood automotive and industrial environments)

Pinout & Package

SOD−123 surface-mount package: 2-terminal, cathode marked by band; dimensions 1.60 mm × 2.69 mm × 1.16 mm; thermoset plastic case with UL 94 V−0 rating and corrosion-resistant, solderable finish.

Pin/Terminal	Circuit Role	Design Meaning
1 (Banded End)	Cathode	Connected to regulated output or voltage reference node; reverse-bias terminal where Zener breakdown occurs
2 (Unbanded End)	Anode	Connected to ground or lower-potential rail; completes bias path for stable voltage clamping

Key Features

Feature	Design Value
AEC−Q101 Qualified	Validated for automotive applications including body control modules and lighting drivers requiring high reliability
Small SOD−123 Footprint	Enables high-density placement in space-constrained designs such as wearable sensors and IoT edge nodes
Low Zener Impedance (25 Ω)	Minimizes voltage deviation during transient current changes - critical for ADC reference stability
High ESD Robustness (>16 kV HBM)	Eliminates need for external ESD protection in front-end signal conditioning stages
Pb−Free Construction	Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements

Applications

Automotive Body Control Unit	Industrial Sensor Signal Conditioning
Use Scenario: Voltage clamping on LIN bus interface lines to suppress load-dump spikes and ESD events. IC Role / Device Role / Timing Role: Zener clamp protecting transceiver input pins against overvoltage beyond 13.5 V. Use Value: Prevents damage to LIN PHY ICs while maintaining signal integrity via low-leakage (<0.1 μA) and fast response.	Use Scenario: Providing stable 12 V reference for 4–20 mA loop-powered pressure transmitters. IC Role / Device Role / Timing Role: Precision shunt regulator establishing accurate excitation voltage for bridge sensors. Use Value: Enables <±0.5% reference accuracy over temperature due to tight 12 V ±5% tolerance and low TC (~+2.2 mV/°C).
Portable Medical Device Power Rail	Smart Home Smoke Detector MCU Supply
Use Scenario: Overvoltage protection on coin-cell–powered microcontroller supply line during battery replacement. IC Role / Device Role / Timing Role: Low-power shunt limiter preventing >12.6 V from reaching sensitive analog front-end circuitry. Use Value: Ultra-low leakage (<0.1 μA) avoids measurable battery drain during standby, extending shelf life.	Use Scenario: Clamping 12 V backup supply rail during AC mains failure and battery switchover transients. IC Role / Device Role / Timing Role: Fast-acting voltage clamp absorbing surge energy before it reaches smoke detection ASIC. Use Value: Withstands non-repetitive surges up to 1 W (1 ms pulse) per Figure 4, ensuring fail-safe operation.

Automotive Body Control Unit

Industrial Sensor Signal Conditioning

Use Scenario: Voltage clamping on LIN bus interface lines to suppress load-dump spikes and ESD events.

IC Role / Device Role / Timing Role: Zener clamp protecting transceiver input pins against overvoltage beyond 13.5 V.

Use Value: Prevents damage to LIN PHY ICs while maintaining signal integrity via low-leakage (<0.1 μA) and fast response.

Use Scenario: Providing stable 12 V reference for 4–20 mA loop-powered pressure transmitters.

IC Role / Device Role / Timing Role: Precision shunt regulator establishing accurate excitation voltage for bridge sensors.

Use Value: Enables <±0.5% reference accuracy over temperature due to tight 12 V ±5% tolerance and low TC (~+2.2 mV/°C).

Portable Medical Device Power Rail

Smart Home Smoke Detector MCU Supply

Use Scenario: Overvoltage protection on coin-cell–powered microcontroller supply line during battery replacement.

IC Role / Device Role / Timing Role: Low-power shunt limiter preventing >12.6 V from reaching sensitive analog front-end circuitry.

Use Value: Ultra-low leakage (<0.1 μA) avoids measurable battery drain during standby, extending shelf life.

Use Scenario: Clamping 12 V backup supply rail during AC mains failure and battery switchover transients.

IC Role / Device Role / Timing Role: Fast-acting voltage clamp absorbing surge energy before it reaches smoke detection ASIC.

Use Value: Withstands non-repetitive surges up to 1 W (1 ms pulse) per Figure 4, ensuring fail-safe operation.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX84-C12LT1G	Same 12 V nominal, but SOT-23 package (larger footprint, higher R_JA = 375°C/W), 350 mW rating	Lower power handling limits use in high-derating scenarios; less suitable for dense automotive PCBs	Select when legacy SOT-23 layout exists and thermal margin exceeds 100°C/W
MMSZ12ET1G	Identical SOD−123 package and electrical specs, but ±2% tolerance (tighter than MMSZ12T1's ±5%)	Higher cost; justified only where reference accuracy dominates BOM cost in metrology-grade instruments	Choose only if system-level calibration requires sub-0.24 V Zener variation at 25°C

Compared with BZX84-C12LT1G and MMSZ12ET1G, the MMSZ12T1 offers optimal balance of automotive qualification, ultra-low leakage, and compact SOD−123 packaging - making it preferred for new designs targeting AEC−Q101 compliance and high board density.

Availability

MMSZ12T1 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, portable medical devices, and smart home safety systems requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MMSZ12T1 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 focused on energy-efficient technologies for automotive, industrial, cloud, and IoT applications.

The MMSZ12T1 belongs to the MMSZxxxT1G Zener regulator series, engineered for reliable voltage reference and overvoltage protection in space-constrained, high-reliability surface-mount applications.

FAQ

What is the Zener voltage tolerance of MMSZ12T1?

The MMSZ12T1 has a nominal Zener voltage of 12 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 11.4 V and 12.6 V when tested at I_ZT = 5 mA and T_A = 25°C. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the official onsemi datasheet (Rev. 13, June 2024). The MMSZ12T1 uses this specification for consistent clamping behavior in production designs.

Is MMSZ12T1 AEC−Q101 qualified?

Yes, the MMSZ12T1 is AEC−Q101 qualified and PPAP capable, as explicitly stated in the Features section of the onsemi datasheet. This qualification validates its suitability for automotive applications including body electronics, lighting, and infotainment subsystems where reliability under thermal cycling and vibration is mandatory. The MMSZ12T1 meets all stress tests defined in the AEC−Q101 standard.

What is the maximum reverse leakage current for MMSZ12T1?

The maximum reverse leakage current for MMSZ12T1 is 0.1 μA at V_R = 9.6 V and T_A = 25°C, per the Electrical Characteristics table on page 2 of the onsemi datasheet. This ultra-low leakage supports energy-sensitive applications like battery-backed sensors and portable medical devices. The MMSZ12T1 maintains this spec across its full operating temperature range.

Does MMSZ12T1 have Pb−free construction?

Yes, the MMSZ12T1 is Pb−free and RoHS-compliant, indicated by the "G" suffix in its full orderable part number MMSZ12T1G. The datasheet confirms Pb−free packages are available and specifies compatibility with standard reflow profiles per JEDEC J-STD-020. The MMSZ12T1 meets environmental compliance requirements for global electronics manufacturing.

What is the thermal resistance of MMSZ12T1 on FR−5 board?

The junction-to-ambient thermal resistance (R_JA) of MMSZ12T1 is 340°C/W when mounted on FR−5 board, as listed in the Maximum Ratings table on page 1 of the onsemi datasheet. This value determines derating behavior: power dissipation must be reduced by 6.7 mW/°C above 75°C ambient. The MMSZ12T1's thermal performance is validated using infrared scanning methodology.

MMSZ12T1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 12 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 25 Ohms

Current - Reverse Leakage @ Vr:: 100 nA @ 8 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

MMSZ12T1 FAQ

1.How can I place an order for MMSZ12T1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ12T1 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 MMSZ12T1 reliable?

The price and inventory of MMSZ12T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ12T1 is usually 5 days.

3.What payment methods are accepted for MMSZ12T1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ12T1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ12T1?

MMSZ12T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ12T1 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 MMSZ12T1?

For technical support, including MMSZ12T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ12T1 requirements.

6.How does Aetrix verify that MMSZ12T1 is sourced from the original manufacturer or authorized distributors?

All MMSZ12T1 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 MMSZ12T1 meets industry standards.

7.What is the process for return or replacement of MMSZ12T1?

All MMSZ12T1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ12T1, 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 MMSZ12T1 part is unused and in its original packaging.

Return procedure for MMSZ12T1:

1.Submit a request within 90 days.

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

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