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

onsemi MMSZ9V1ET1

Name: MMSZ9V1ET1
Brand: onsemi
SKU: MMSZ9V1ET1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ9V1ET1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ9V1ET1.pdf

Description:: DIODE ZENER 9.1V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:7,719

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Product details

Overview

MMSZ9V1ET1 from onsemi is a 9.1 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 15 Ω dynamic impedance at 5 mA test current and 0.5 µA reverse leakage at 8.4 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.

For engineers reviewing the MMSZ9V1ET1 datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal derating behavior, ESD robustness (Class 3, >16 kV HBM), peak surge capability (225 W, 8 × 20 µs), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This device operates as a two-terminal voltage reference by maintaining a stable reverse breakdown voltage across its cathode-anode terminals under controlled Zener current. It exhibits a nominal temperature coefficient near zero (±2 mV/°C typical for 9.1 V grade) and supports stable regulation from −55 °C to +150 °C junction temperature.

Its SOD-123 package delivers 340 °C/W junction-to-ambient thermal resistance on FR-5 board and enables automated placement in high-density PCB layouts. The device meets AEC-Q101 stress testing requirements and carries Class 3 ESD rating (>16 kV HBM), confirming suitability for automotive and industrial environments where transient immunity and long-term stability are critical.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	8.65–9.56 V at I_ZT = 5 mA; ensures ±5% regulation accuracy for 9.1 V nominal reference
Dynamic Impedance (Z_ZT)	15 Ω max at I_ZT = 5 mA; limits output voltage variation under load current changes
Reverse Leakage (I_R)	0.5 µA max at V_R = 8.4 V; minimizes standby power loss in battery-powered systems
Power Dissipation (P_D)	500 mW at T_L = 75 °C on FR-5 board; defines continuous operating limit before thermal derating begins
Peak Surge Power (P_Pk)	225 W for 8 × 20 µs pulse; provides transient overvoltage clamping without failure
ESD Rating	Class 3 (>16 kV) per Human Body Model; eliminates need for external ESD protection in many interfaces
Junction Temp Range	−55 °C to +150 °C; supports operation in under-hood automotive and industrial control environments

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 (Banded End)	Cathode	Connected to regulated voltage rail; reverse-biased terminal during Zener operation
2 (Non-banded End)	Anode	Connected to ground or lower-potential node; completes current path during regulation

Key Features

Feature	Design Value
AEC-Q101 Qualified	Validated for automotive applications including engine control modules and body electronics
500 mW Power Rating	Enables use in compact, thermally constrained designs without forced cooling
Class 3 ESD Robustness	Withstands >16 kV human-body discharges without parameter shift or failure
Small SOD-123 Footprint	Supports high-density PCB layouts in space-constrained IoT sensors and portable devices
Pb-Free Construction	Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profiles

Applications

Automotive Sensor Signal Conditioning	Industrial PLC Input Protection
Use Scenario: Stabilizing reference voltage for analog front-end of temperature or pressure sensors in engine bay modules. IC Role / Device Role / Timing Role: Zener diode providing precise 9.1 V shunt reference for ADC biasing and signal scaling. Use Value: Maintains <±1% regulation accuracy across −40 °C to +125 °C ambient, enabling reliable sensor calibration without trimming.	Use Scenario: Clamping transient surges on 24 V digital input channels of programmable logic controllers. IC Role / Device Role / Timing Role: Shunt protector absorbing 225 W surge energy (8 × 20 µs) to prevent damage to downstream optocouplers and microcontrollers. Use Value: Eliminates need for TVS diodes in cost-sensitive I/O modules while meeting IEC 61000-4-5 Level 3 immunity requirements.
Portable Medical Device Power Supervision	Consumer Audio DC Bias Reference
Use Scenario: Monitoring battery voltage thresholds in wearable ECG monitors using low-quiescent-current comparators. IC Role / Device Role / Timing Role: Low-leakage (0.5 µA max) Zener reference generating stable trip point for undervoltage lockout circuitry. Use Value: Extends battery life by minimizing parasitic current draw while ensuring accurate 9.1 V detection threshold over full temperature range.	Use Scenario: Establishing DC bias point for Class AB headphone amplifier stages in Bluetooth speakers. IC Role / Device Role / Timing Role: Precision shunt regulator setting quiescent operating point for dual-rail op-amp supply rails. Use Value: Reduces harmonic distortion by stabilizing bias voltage against supply ripple, leveraging 15 Ω Z_ZT for tight regulation under varying load conditions.

Automotive Sensor Signal Conditioning

Industrial PLC Input Protection

Use Scenario: Stabilizing reference voltage for analog front-end of temperature or pressure sensors in engine bay modules.

IC Role / Device Role / Timing Role: Zener diode providing precise 9.1 V shunt reference for ADC biasing and signal scaling.

Use Value: Maintains <±1% regulation accuracy across −40 °C to +125 °C ambient, enabling reliable sensor calibration without trimming.

Use Scenario: Clamping transient surges on 24 V digital input channels of programmable logic controllers.

IC Role / Device Role / Timing Role: Shunt protector absorbing 225 W surge energy (8 × 20 µs) to prevent damage to downstream optocouplers and microcontrollers.

Use Value: Eliminates need for TVS diodes in cost-sensitive I/O modules while meeting IEC 61000-4-5 Level 3 immunity requirements.

Portable Medical Device Power Supervision

Consumer Audio DC Bias Reference

Use Scenario: Monitoring battery voltage thresholds in wearable ECG monitors using low-quiescent-current comparators.

IC Role / Device Role / Timing Role: Low-leakage (0.5 µA max) Zener reference generating stable trip point for undervoltage lockout circuitry.

Use Value: Extends battery life by minimizing parasitic current draw while ensuring accurate 9.1 V detection threshold over full temperature range.

Use Scenario: Establishing DC bias point for Class AB headphone amplifier stages in Bluetooth speakers.

IC Role / Device Role / Timing Role: Precision shunt regulator setting quiescent operating point for dual-rail op-amp supply rails.

Use Value: Reduces harmonic distortion by stabilizing bias voltage against supply ripple, leveraging 15 Ω Z_ZT for tight regulation under varying load conditions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX84-C9V1	Same 9.1 V ±5% rating but SOT-23 package; higher R_JA (450 °C/W); 350 mW P_D rating	Less suitable for high-temperature PCB locations due to reduced thermal performance	Select when footprint compatibility with existing SOT-23 designs is required and thermal margin exceeds 25 °C
MMBZ5240BLT1G	9.1 V ±5%, SOT-23 package, 225 mW P_D, 30 Ω Z_ZT; no AEC-Q101 qualification	Not qualified for automotive use; limited surge capability (100 W peak)	Choose for cost-sensitive consumer applications where AEC-Q101 and 225 W surge are not required

Compared with BZX84-C9V1 and MMBZ5240BLT1G, the MMSZ9V1ET1 offers superior thermal performance (500 mW vs ≤350 mW), higher surge robustness (225 W), and automotive qualification-making it the preferred choice for demanding industrial and automotive voltage reference roles.

Availability

MMSZ9V1ET1 is available at Aetrix Electronics and suitable for automotive sensor modules, industrial PLC input protection, and portable medical device power supervision requiring stable component supply and long-term lifecycle support.

Supply support for MMSZ9V1ET1 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications, with leadership in power management, analog, sensors, and connectivity.

The MMSZxxxET1G series was designed specifically for high-reliability, surface-mount Zener regulation in space-constrained and thermally demanding environments-including under-hood automotive electronics and factory automation equipment.

FAQ

What is the Zener voltage tolerance of the MMSZ9V1ET1?

The MMSZ9V1ET1 has a nominal Zener voltage of 9.1 V with a standard tolerance of ±5%, meaning the actual measured V_Z falls between 8.65 V and 9.56 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), and applies across the full operating temperature range when derated per Figure 3.

Does the MMSZ9V1ET1 meet automotive qualification standards?

Yes, the MMSZ9V1ET1 is AEC-Q101 qualified and PPAP capable, as explicitly stated in the Specification Features section of the onsemi datasheet. This qualification covers stress tests including high-temperature operating life, temperature cycling, and ESD, making the MMSZ9V1ET1 suitable for automotive applications such as body control modules and sensor interfaces where reliability under harsh environmental conditions is mandatory.

What is the maximum reverse leakage current for the MMSZ9V1ET1?

The MMSZ9V1ET1 specifies a maximum reverse leakage current (I_R) of 0.5 µA at V_R = 8.4 V, as listed in the Electrical Characteristics table on page 2 of the onsemi datasheet. This value is measured at T_A = 25 °C and reflects the device's low standby power consumption-critical for battery-powered systems where quiescent current must be minimized without sacrificing regulation accuracy.

Can the MMSZ9V1ET1 handle transient surge events?

Yes, the MMSZ9V1ET1 is rated for a nonrepetitive peak surge power of 225 W with an 8 × 20 µs waveform, as defined in the Maximum Ratings table and illustrated in Figure 4 of the onsemi datasheet. This capability allows the MMSZ9V1ET1 to safely clamp fast transients-such as EFT bursts or inductive switch-off spikes-without degradation, supporting robust overvoltage protection in industrial and automotive power rails.

What package type does the MMSZ9V1ET1 use and what are its key mechanical features?

The MMSZ9V1ET1 uses the SOD-123 surface-mount package (Case 425, Style 1), measuring 1.60 × 2.69 × 1.16 mm. Key mechanical features include a void-free thermosetting plastic case, corrosion-resistant solderable finish, cathode polarity band marking, UL 94 V-0 flammability rating, and 260 °C/10 s maximum soldering temperature-enabling reliable automated assembly in high-density PCB manufacturing.

MMSZ9V1ET1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 9.1 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 15 Ohms

Current - Reverse Leakage @ Vr:: 500 nA @ 6 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

MMSZ9V1ET1 FAQ

1.How can I place an order for MMSZ9V1ET1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ9V1ET1 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 MMSZ9V1ET1 reliable?

The price and inventory of MMSZ9V1ET1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ9V1ET1 is usually 5 days.

3.What payment methods are accepted for MMSZ9V1ET1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ9V1ET1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ9V1ET1?

MMSZ9V1ET1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ9V1ET1 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 MMSZ9V1ET1?

For technical support, including MMSZ9V1ET1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ9V1ET1 requirements.

6.How does Aetrix verify that MMSZ9V1ET1 is sourced from the original manufacturer or authorized distributors?

All MMSZ9V1ET1 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 MMSZ9V1ET1 meets industry standards.

7.What is the process for return or replacement of MMSZ9V1ET1?

All MMSZ9V1ET1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ9V1ET1, 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 MMSZ9V1ET1 part is unused and in its original packaging.

Return procedure for MMSZ9V1ET1:

1.Submit a request within 90 days.

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

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