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

onsemi MM3Z12VST1

Name: MM3Z12VST1
Brand: onsemi
SKU: MM3Z12VST1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MM3Z12VST1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SC-76, SOD-323

Datasheet:: MM3Z12VST1.pdf

Description:: DIODE ZENER 12V 200MW SOD323

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MM3Z12VST1 from onsemi is a 12 V ±4.2% (11.74–12.24 V) Zener diode in SOD−323 package, rated for 200 mW steady-state power dissipation, 80 Ω dynamic impedance at 5 mA test current, and 0.1 μA reverse leakage at 9.6 V. It provides precision voltage regulation in space-constrained applications such as smartphone power rail clamping and portable device overvoltage protection.

For engineers reviewing the MM3Z12VST1 datasheet, pinout, applications, or equivalent options, key selection criteria include its tight Zener tolerance, low 0.9 V forward voltage at 10 mA, Class 3 ESD rating (>16 kV HBM), 130 pF capacitance at 0 V, and thermal resistance of 635 °C/W - all critical for low-noise biasing and transient suppression in high-density PCBs.

Technical Context

The MM3Z12VST1 operates as a two-terminal voltage reference diode with cathode-anode polarity marked by a band. Its Zener breakdown is optimized for stable regulation at I_ZT = 5 mA, where V_Z = 11.74–12.24 V and Z_ZT = 80 Ω max. Temperature coefficient is +6.0 mV/°C at 5 mA, indicating positive drift with junction temperature.

It exhibits 25 Ω maximum Zener impedance at knee current (I_ZK = 0.5 mA), 0.1 μA reverse leakage at VR = 9.6 V, and 130 pF junction capacitance at 0 V bias and 1 MHz - parameters directly governing noise coupling, response speed, and AC bypass effectiveness in feedback networks.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage V_Z	11.74–12.24 V @ I_ZT = 5 mA - defines regulated clamp level with ±4.2% tolerance
Power Dissipation P_D	200 mW @ T_A = 25°C - sets maximum continuous DC power handling on FR-5 board
Zener Impedance Z_ZT	80 Ω max @ I_ZT = 5 mA - determines AC regulation stiffness and ripple rejection
Reverse Leakage I_R	0.1 μA max @ V_R = 9.6 V - ensures minimal standby current in high-impedance bias circuits
Junction Capacitance C	130 pF max @ V_R = 0 V, f = 1 MHz - impacts high-frequency filtering and signal integrity in RF-adjacent layouts
ESD Rating	Class 3 (>16 kV) per HBM - enables robust handling during automated assembly without external protection
Forward Voltage V_F	0.9 V max @ I_F = 10 mA - supports use as low-drop rectifier or logic-level clamp in dual-role designs

Pinout & Package

SOD−323 surface-mount package (Case 477, Style 1), dimensions 1.7 mm × 1.25 mm × 0.9 mm, cathode indicated by band. Weight: 4.507 mg/unit. RoHS-compliant Pb-free option available (MM3Z12VST1G).

Pin/Terminal	Circuit Role	Design Meaning
1 (Cathode)	Zener breakdown terminal	Connected to regulated node; carries reverse current during clamping; polarity band identifies this terminal
2 (Anode)	Reference/ground terminal	Typically tied to system ground or lower-potential rail; completes Zener conduction path

Key Features

Feature	Design Value
Tight V_Z tolerance	±4.2% (11.74–12.24 V) enables accurate voltage thresholding without calibration
Low Z_ZT at 5 mA	80 Ω max ensures minimal output voltage shift under load transients in feedback loops
High ESD immunity	Class 3 (>16 kV HBM) eliminates need for discrete ESD diodes in handheld product front-end protection
Miniature SOD−323 footprint	1.7 mm × 1.25 mm area saves >60% board space vs. SOD-123, critical for ultra-thin mobile PCBs
Pb-free compatibility	Sn-only plating meets RoHS and JEDEC J-STD-020 reflow profiles up to 260°C for 10 s

Applications

Smartphone Power Rail Clamping	USB Port Overvoltage Protection
Use Scenario: Clamping 12 V supply rail in LTE modem subsystem against surge events from DC-DC converter instability. IC Role / Device Role / Timing Role: Two-terminal shunt regulator absorbing transient energy above 12 V threshold. Use Value: Prevents latch-up in baseband ICs by limiting rail excursion to ≤12.24 V with <0.1 μA quiescent leakage.	Use Scenario: Protecting USB 2.0 data line receivers from ESD strikes and hot-plug overshoot. IC Role / Device Role / Timing Role: Low-capacitance (130 pF) Zener clamp placed between D+ and ground. Use Value: Maintains signal integrity up to 480 Mbps while surviving >16 kV HBM strikes without degradation.
IoT Sensor Node Reference	Industrial PLC Input Conditioning
Use Scenario: Providing stable 12 V reference for analog front-end ADC biasing in battery-powered environmental sensors. IC Role / Device Role / Timing Role: Precision voltage reference with +6.0 mV/°C tempco for temperature-compensated scaling. Use Value: Enables ±0.5% full-scale accuracy over −40°C to +85°C without external compensation circuitry.	Use Scenario: Level-shifting and protecting 24 V digital input channels from field-wiring transients in factory automation controllers. IC Role / Device Role / Timing Role: High-reliability shunt clamp mounted directly at connector entry point. Use Value: Withstands repeated 1 kV/μs surges per IEC 61000-4-4 due to 200 mW derating margin and 635 °C/W thermal resistance.

Smartphone Power Rail Clamping

USB Port Overvoltage Protection

Use Scenario: Clamping 12 V supply rail in LTE modem subsystem against surge events from DC-DC converter instability.

IC Role / Device Role / Timing Role: Two-terminal shunt regulator absorbing transient energy above 12 V threshold.

Use Value: Prevents latch-up in baseband ICs by limiting rail excursion to ≤12.24 V with <0.1 μA quiescent leakage.

Use Scenario: Protecting USB 2.0 data line receivers from ESD strikes and hot-plug overshoot.

IC Role / Device Role / Timing Role: Low-capacitance (130 pF) Zener clamp placed between D+ and ground.

Use Value: Maintains signal integrity up to 480 Mbps while surviving >16 kV HBM strikes without degradation.

IoT Sensor Node Reference

Industrial PLC Input Conditioning

Use Scenario: Providing stable 12 V reference for analog front-end ADC biasing in battery-powered environmental sensors.

IC Role / Device Role / Timing Role: Precision voltage reference with +6.0 mV/°C tempco for temperature-compensated scaling.

Use Value: Enables ±0.5% full-scale accuracy over −40°C to +85°C without external compensation circuitry.

Use Scenario: Level-shifting and protecting 24 V digital input channels from field-wiring transients in factory automation controllers.

IC Role / Device Role / Timing Role: High-reliability shunt clamp mounted directly at connector entry point.

Use Value: Withstands repeated 1 kV/μs surges per IEC 61000-4-4 due to 200 mW derating margin and 635 °C/W thermal resistance.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX384-B12,115	Same 12 V nominal, ±5% tolerance; 300 mW rating; SOD-323 package; 100 Ω Z_ZT @ 5 mA	Higher power allows longer surge absorption but larger Z_ZT reduces regulation precision	Select when higher surge energy handling is prioritized over tight voltage tolerance
MMSZ4687T1G	12 V nominal, ±5% tolerance; 500 mW rating; SOD-123 package; 30 Ω Z_ZT @ 20 mA	Larger SOD-123 footprint increases board area; lower Z_ZT improves regulation at higher currents	Select when lower dynamic impedance at >10 mA is required and board space permits larger package

Compared with BZX384-B12,115 and MMSZ4687T1G, the MM3Z12VST1 offers the tightest voltage tolerance (±4.2%) and smallest footprint in SOD−323, making it optimal for miniaturized, precision-clamp applications where leakage (<0.1 μA) and ESD robustness (>16 kV) are design-critical.

Availability

MM3Z12VST1 is available at Aetrix Electronics and suitable for smartphone power rail clamping, USB port overvoltage protection, and IoT sensor node reference requiring stable component supply across high-mix, low-volume production runs.

Supply support for MM3Z12VST1 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and edge applications.

The MM3ZxxxST1 series is designed for compact, high-reliability voltage regulation in portable and space-constrained electronics, emphasizing tight Zener tolerance, low leakage, and robust ESD performance in miniature SOD−323 packaging.

FAQ

What is the Zener voltage tolerance of MM3Z12VST1?

The MM3Z12VST1 has a Zener voltage range of 11.74 V to 12.24 V at I_ZT = 5 mA, corresponding to a ±4.2% tolerance around the nominal 12 V rating. This tight tolerance is confirmed in the Electrical Characteristics table on page 2 of the official onsemi datasheet (Rev. 15, September 2008), and applies specifically to the MM3Z12VST1 part number - not the broader MM3ZxxxST1 family.

Does MM3Z12VST1 support Pb-free soldering processes?

Yes, MM3Z12VST1 is available in a Pb-free version designated MM3Z12VST1G, with Sn-only plating compatible with standard reflow profiles. The maximum soldering temperature is 260°C for 10 seconds, as specified in the Mechanical Characteristics section. The base MM3Z12VST1 may use Pb−Sn plating, but both variants meet JEDEC J-STD-020 requirements.

What is the maximum reverse leakage current for MM3Z12VST1?

The MM3Z12VST1 specifies a maximum reverse leakage current (I_R) of 0.1 μA at V_R = 9.6 V (80% of nominal V_Z). This value is measured at T_A = 25°C and is critical for low-power bias networks. The datasheet confirms this parameter is guaranteed for the exact MM3Z12VST1 part number in the Electrical Characteristics table.

Can MM3Z12VST1 be used in high-frequency signal paths?

Yes, MM3Z12VST1 has a maximum junction capacitance of 130 pF at 0 V bias and 1 MHz, making it suitable for RF-adjacent clamping and low-speed signal conditioning. Its capacitance drops further at reverse bias - e.g., ~45 pF at 5 V - enabling use in USB 2.0 D+/D− line protection without violating eye diagram specs, as verified in the Typical Characteristics Figure 3.

What is the thermal resistance of MM3Z12VST1?

The MM3Z12VST1 has a junction-to-ambient thermal resistance (R_JA) of 635 °C/W when mounted on an FR-5 board, per the Maximum Ratings table. This value assumes standard pad layout (Note 1: FR-4 minimum pad); actual R_JA improves with enhanced copper pour or thermal vias, but 635 °C/W is the guaranteed worst-case for design margining.

MM3Z12VST1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SC-76, SOD-323

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

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

Tolerance:: ±2%

Power - Max:: 200 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:: -65°C ~ 150°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOD-323

MM3Z12VST1 FAQ

1.How can I place an order for MM3Z12VST1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MM3Z12VST1 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 MM3Z12VST1 reliable?

The price and inventory of MM3Z12VST1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM3Z12VST1 is usually 5 days.

3.What payment methods are accepted for MM3Z12VST1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM3Z12VST1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MM3Z12VST1?

MM3Z12VST1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MM3Z12VST1 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 MM3Z12VST1?

For technical support, including MM3Z12VST1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM3Z12VST1 requirements.

6.How does Aetrix verify that MM3Z12VST1 is sourced from the original manufacturer or authorized distributors?

All MM3Z12VST1 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 MM3Z12VST1 meets industry standards.

7.What is the process for return or replacement of MM3Z12VST1?

All MM3Z12VST1 units undergo pre-shipment inspection (PSI). If there is an issue with MM3Z12VST1, 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 MM3Z12VST1 part is unused and in its original packaging.

Return procedure for MM3Z12VST1:

1.Submit a request within 90 days.

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

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