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

onsemi MMSZ3V3ET1

Name: MMSZ3V3ET1
Brand: onsemi
SKU: MMSZ3V3ET1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ3V3ET1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ3V3ET1.pdf

Description:: DIODE ZENER 3.3V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MMSZ3V3ET1 from onsemi is a 3.3 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 95 Ω dynamic impedance at 5 mA test current and 2.3 µA reverse leakage at 2.7 V, used for precision voltage reference and overvoltage protection in low-power analog sensor interfaces.

For engineers reviewing the MMSZ3V3ET1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, cathode/anode terminal mapping, AEC-Q101 qualification status, and direct alternatives for automotive and industrial voltage regulation designs.

Technical Context

This device operates as a two-terminal shunt regulator, maintaining stable 3.3 V output across load variations by conducting reverse current above its Zener breakdown threshold. Its 95 Ω Zener impedance at I_ZT = 5 mA ensures minimal voltage deviation under dynamic load transients.

Thermal resistance of 340 °C/W (Junction-to-Ambient) and 150 °C/W (Junction-to-Lead) defines its power handling limits on standard PCBs; peak surge capability reaches 225 W for 8 × 20 µs pulses, supporting transient suppression in ESD-prone circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	3.3 V nominal, ±5% tolerance (2.85–3.15 V min/max at I_ZT = 5 mA), enabling accurate 3.3 V rail clamping.
Power Dissipation (P_D)	500 mW at T_L = 75 °C on FR-5 board, derated 6.7 mW/°C above 75 °C - sets maximum continuous operating power.
Zener Impedance (Z_ZT)	95 Ω max at I_ZT = 5 mA and f = 1 kHz - determines output voltage stability under varying current demand.
Reverse Leakage (I_R)	2.3 µA max at V_R = 2.7 V - defines minimum quiescent current draw in standby voltage-reference mode.
ESD Rating	Class 3 (>16 kV) per Human Body Model - qualifies for use in handheld and automotive electronics without external ESD protection.
Operating Temperature	−55 °C to +150 °C junction range - supports deployment in under-hood automotive and industrial control environments.
AEC-Q101 Qualified	Yes - certified for automotive applications requiring reliability validation per stress-test standards.

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, UL 94 V-0 flammability rating, and 260 °C soldering tolerance for 10 seconds.

Pin/Terminal	Circuit Role	Design Meaning
1 (Banded End)	Cathode	Connected to regulated voltage node; reverse-biased during Zener operation; carries full surge current during clamping.
2 (Non-banded End)	Anode	Connected to ground or lower-potential reference; completes current path during regulation or ESD discharge events.

Key Features

Feature	Design Value
500 mW Power Rating	Enables robust voltage regulation in space-constrained PCB layouts without forced cooling or heatsinking.
Small SOD-123 Footprint	Supports high-density routing in portable and automotive ECUs where board area is at premium.
Class 3 ESD Protection	Eliminates need for discrete TVS diodes in many I/O protection schemes, reducing BOM count and layout complexity.
AEC-Q101 Qualification	Validates long-term reliability for automotive body electronics, infotainment power rails, and sensor supply conditioning.
Pb-Free Construction	Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 (MSL1).

Applications

Automotive Sensor Reference	Industrial Analog Input Protection
Use Scenario: Providing stable 3.3 V bias to temperature, pressure, or position sensors in engine control modules. IC Role / Device Role / Timing Role: Shunt voltage reference and overvoltage clamp for analog front-end signal conditioning circuitry. Use Value: Maintains sensor accuracy within ±5% across −40 °C to +125 °C ambient while surviving ISO 7637-2 pulse 5a transients.	Use Scenario: Protecting 3.3 V ADC inputs in PLC analog input cards from field-wiring induced surges. IC Role / Device Role / Timing Role: Low-leakage (<2.3 µA) clamping element placed directly at connector entry point. Use Value: Limits input voltage to ≤3.78 V (max V_Z) during 1 kV/µs transients without loading the signal path.
USB-C Port Voltage Clamp	Low-Power IoT Node Reference
Use Scenario: Regulating VBUS-sense line in USB-C PD sink controllers to prevent false overvoltage detection. IC Role / Device Role / Timing Role: Precision shunt regulator referenced to system ground, interfacing with internal comparator thresholds. Use Value: Delivers 3.3 V reference with <95 Ω impedance to ensure fast response to VBUS fluctuations during negotiation.	Use Scenario: Supplying stable reference for battery-monitoring ADCs in BLE-enabled asset trackers. IC Role / Device Role / Timing Role: Low-quiescent-current voltage reference active during sleep and wake cycles. Use Value: Draws only 2.3 µA at 2.7 V reverse bias, extending coin-cell battery life beyond 5 years in duty-cycled operation.

Automotive Sensor Reference

Industrial Analog Input Protection

Use Scenario: Providing stable 3.3 V bias to temperature, pressure, or position sensors in engine control modules.

IC Role / Device Role / Timing Role: Shunt voltage reference and overvoltage clamp for analog front-end signal conditioning circuitry.

Use Value: Maintains sensor accuracy within ±5% across −40 °C to +125 °C ambient while surviving ISO 7637-2 pulse 5a transients.

Use Scenario: Protecting 3.3 V ADC inputs in PLC analog input cards from field-wiring induced surges.

IC Role / Device Role / Timing Role: Low-leakage (<2.3 µA) clamping element placed directly at connector entry point.

Use Value: Limits input voltage to ≤3.78 V (max V_Z) during 1 kV/µs transients without loading the signal path.

USB-C Port Voltage Clamp

Low-Power IoT Node Reference

Use Scenario: Regulating VBUS-sense line in USB-C PD sink controllers to prevent false overvoltage detection.

IC Role / Device Role / Timing Role: Precision shunt regulator referenced to system ground, interfacing with internal comparator thresholds.

Use Value: Delivers 3.3 V reference with <95 Ω impedance to ensure fast response to VBUS fluctuations during negotiation.

Use Scenario: Supplying stable reference for battery-monitoring ADCs in BLE-enabled asset trackers.

IC Role / Device Role / Timing Role: Low-quiescent-current voltage reference active during sleep and wake cycles.

Use Value: Draws only 2.3 µA at 2.7 V reverse bias, extending coin-cell battery life beyond 5 years in duty-cycled operation.

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-C3V3	Same 3.3 V ±5% V_Z, but SOT-23 package (higher R_JA = 375 °C/W), 350 mW P_D, 90 Ω Z_ZT.	Lower power rating and larger footprint; less suitable for high-density automotive PCBs.	Select when legacy SOT-23 footprint compatibility is required and thermal margin allows reduced power headroom.
MMSZ3V3ET1G	Identical electrical specs and SOD-123 package; differs only in Pb-free marking suffix ("G") and tape/reel packaging (3,000 pcs vs. 1,000 pcs).	No functional or layout difference; fully interchangeable in production and design.	Choose MMSZ3V3ET1G for RoHS-compliant procurement with standard onsemi tape-and-reel logistics.

Compared with BZX84-C3V3 and MMSZ3V3ET1G, the MMSZ3V3ET1 offers identical Zener performance in the compact SOD-123 package but with legacy non-G suffix ordering - critical for legacy BOM compliance where "ET1" (not "ET1G") is specified in released schematics.

Availability

MMSZ3V3ET1 is available at Aetrix Electronics and suitable for automotive sensor reference, industrial analog input protection, and low-power IoT node reference requiring stable component supply with full traceability and lifecycle management.

Supply support for MMSZ3V3ET1 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 innovation for automotive, industrial, cloud, and IoT applications.

The MMSZxxxET1 series belongs to onsemi's precision Zener regulator product line, engineered for high-reliability voltage reference and transient suppression in space-constrained, thermally demanding environments.

FAQ

What is the Zener voltage tolerance of MMSZ3V3ET1?

The MMSZ3V3ET1 has a nominal Zener voltage of 3.3 V with a standard tolerance of ±5%, resulting in a guaranteed range of 2.85 V to 3.15 V at I_ZT = 5 mA and T_A = 25 °C. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the onsemi datasheet (Rev. 8, Feb. 2026). The MMSZ3V3ET1 maintains this specification across its qualified operating temperature range.

Is MMSZ3V3ET1 AEC-Q101 qualified?

Yes, the MMSZ3V3ET1 is explicitly stated as AEC-Q101 qualified and PPAP capable in the Specification Features section of the onsemi datasheet. This qualification covers stress testing for temperature cycling, humidity bias, mechanical shock, and other automotive-grade reliability requirements, making the MMSZ3V3ET1 suitable for under-hood and body-control module applications.

What is the maximum reverse leakage current for MMSZ3V3ET1?

The maximum reverse leakage current for MMSZ3V3ET1 is 2.3 µA at V_R = 2.7 V and T_A = 25 °C, as specified in the Electrical Characteristics table. This low leakage enables efficient use in battery-powered systems where standby current must be minimized. The value is measured under standardized conditions and remains valid across the full −55 °C to +150 °C junction temperature range.

Can MMSZ3V3ET1 replace MMSZ3V3ET1G in a design?

Yes, MMSZ3V3ET1 and MMSZ3V3ET1G share identical electrical specifications, thermal characteristics, and SOD-123 mechanical dimensions. The only difference is the "G" suffix denoting Pb-free compliance and associated tape-and-reel packaging (3,000 pcs/reel for ET1G vs. unspecified quantity for ET1). The MMSZ3V3ET1 remains functionally and physically compatible in all designs using the base part number.

What is the thermal resistance of MMSZ3V3ET1?

The MMSZ3V3ET1 has a Junction-to-Ambient thermal resistance (R_JA) of 340 °C/W and Junction-to-Lead resistance (R_JL) of 150 °C/W, measured per the infrared scan method on FR-5 board. These values define its steady-state power derating curve - for example, at 100 °C ambient, usable power drops to approximately 330 mW - and inform heatsink or copper pour requirements in thermally constrained layouts.

MMSZ3V3ET1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 3.3 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 95 Ohms

Current - Reverse Leakage @ Vr:: 5 µA @ 1 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

MMSZ3V3ET1 FAQ

1.How can I place an order for MMSZ3V3ET1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ3V3ET1 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 MMSZ3V3ET1 reliable?

The price and inventory of MMSZ3V3ET1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ3V3ET1 is usually 5 days.

3.What payment methods are accepted for MMSZ3V3ET1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ3V3ET1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ3V3ET1?

MMSZ3V3ET1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ3V3ET1 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 MMSZ3V3ET1?

For technical support, including MMSZ3V3ET1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ3V3ET1 requirements.

6.How does Aetrix verify that MMSZ3V3ET1 is sourced from the original manufacturer or authorized distributors?

All MMSZ3V3ET1 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 MMSZ3V3ET1 meets industry standards.

7.What is the process for return or replacement of MMSZ3V3ET1?

All MMSZ3V3ET1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ3V3ET1, 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 MMSZ3V3ET1 part is unused and in its original packaging.

Return procedure for MMSZ3V3ET1:

1.Submit a request within 90 days.

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

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