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

onsemi MMSZ27T1

Name: MMSZ27T1
Brand: onsemi
SKU: MMSZ27T1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ27T1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ27T1.pdf

Description:: DIODE ZENER 27V 500MW SOD-123

Quantity:: RFQ Add To RFQ list

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Inventory:9,682

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Product details

Overview

MMSZ27T1 from onsemi is a 27 V, ±5% tolerance Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C on FR−5 board, with 80 Ω dynamic impedance at 2 mA and 0.05 µA reverse leakage at 18.9 V, used for precision voltage regulation and overvoltage protection in automotive power rails and industrial sensor interfaces.

For engineers reviewing the MMSZ27T1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, AEC−Q101 qualification status, and direct alternatives for voltage reference design, ESD clamp circuits, and supply rail stabilization.

Technical Context

The MMSZ27T1 operates as a two-terminal silicon Zener regulator with sharp reverse breakdown at nominal 27 V, specified under pulsed 1 ms conditions per JEDEC standards. Its 80 Ω Zener impedance at IZT = 2 mA ensures stable regulation under moderate load transients.

Thermal performance is defined by RJA = 340°C/W and RJL = 150°C/W, enabling operation from −55°C to +150°C junction temperature. It meets Class 3 ESD rating (>16 kV HBM) and is AEC−Q101 qualified for automotive use.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	25.65–28.35 V @ I_ZT = 2 mA; ±5% tolerance enables accurate clamping in 24 V system rails.
Power Dissipation (P_D)	500 mW @ T_L = 75°C; derates linearly at 6.7 mW/°C above 75°C for thermal-aware PCB layout.
Zener Impedance (Z_ZT)	80 Ω @ I_ZT = 2 mA; low dynamic resistance supports stable regulation under varying load current.
Reverse Leakage (I_R)	0.05 µA @ V_R = 18.9 V; minimal standby current preserves battery life in always-on monitoring circuits.
ESD Rating	Class 3 (>16 kV) per HBM; protects downstream circuitry from human-handling electrostatic discharge.
Junction Temp Range	−55°C to +150°C; validated for under-hood automotive and industrial control environments.

Pinout & Package

SOD−123 surface-mount package: 1.60 mm × 2.69 mm × 1.16 mm, void-free thermosetting plastic case with cathode band marking; polarity band indicates Pin 1 (Cathode), Pin 2 (Anode).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Banded End)	Cathode	Connected to regulated output node; reverse-biased during Zener operation; must be routed to higher-potential rail.
Pin 2 (Non-banded End)	Anode	Connected to ground or lower-potential reference; completes current path during breakdown conduction.

Key Features

Feature	Design Value
AEC−Q101 Qualified	Validated for automotive applications including engine control modules and body electronics requiring PPAP documentation.
Pb−Free (RoHS Compliant)	Meets EU RoHS Directive 2011/65/EU; marked with "G" suffix and microdot indicator per onsemi packaging standard.
High-Density Mounting	SOD−123 footprint allows placement in space-constrained designs such as portable instrumentation and multi-rail PMIC boards.
Optimized for Automated Assembly	Transfer-molded case geometry and solderable finish ensure reliable pick-and-place and reflow yield on high-speed SMT lines.

Applications

Automotive Power Rail Clamp	Industrial Sensor Reference
Use Scenario: Clamping transient spikes on 24 V CAN bus power line during load dump events. IC Role / Device Role / Timing Role: Two-terminal passive voltage clamp absorbing surge energy without active control. Use Value: Withstands 500 mW peak pulse power and maintains <28.35 V clamping threshold across −40°C to +125°C ambient.	Use Scenario: Providing stable 27 V reference for analog front-end of pressure transducer signal conditioning. IC Role / Device Role / Timing Role: Precision shunt reference establishing known bias point for op-amp gain stages. Use Value: ±5% V_Z tolerance and 80 Ω Z_ZT ensure <0.5% reference drift under 1–5 mA load variation.
ESD Protection Node	Programmable Logic Supply Monitor
Use Scenario: Secondary ESD clamp on I/O line of automotive MCU, placed after primary TVS diode. IC Role / Device Role / Timing Role: Low-leakage secondary clamp limiting residual voltage to safe logic thresholds. Use Value: 0.05 µA leakage at 18.9 V prevents false triggering while Class 3 HBM rating adds robustness.	Use Scenario: Undervoltage detection input for FPGA configuration controller monitoring 27 V auxiliary supply. IC Role / Device Role / Timing Role: Threshold-setting element feeding comparator input to generate reset signal. Use Value: Tight 25.65–28.35 V range enables precise trip point definition without external trimming resistors.

Automotive Power Rail Clamp

Industrial Sensor Reference

Use Scenario: Clamping transient spikes on 24 V CAN bus power line during load dump events.

IC Role / Device Role / Timing Role: Two-terminal passive voltage clamp absorbing surge energy without active control.

Use Value: Withstands 500 mW peak pulse power and maintains <28.35 V clamping threshold across −40°C to +125°C ambient.

Use Scenario: Providing stable 27 V reference for analog front-end of pressure transducer signal conditioning.

IC Role / Device Role / Timing Role: Precision shunt reference establishing known bias point for op-amp gain stages.

Use Value: ±5% V_Z tolerance and 80 Ω Z_ZT ensure <0.5% reference drift under 1–5 mA load variation.

ESD Protection Node

Programmable Logic Supply Monitor

Use Scenario: Secondary ESD clamp on I/O line of automotive MCU, placed after primary TVS diode.

IC Role / Device Role / Timing Role: Low-leakage secondary clamp limiting residual voltage to safe logic thresholds.

Use Value: 0.05 µA leakage at 18.9 V prevents false triggering while Class 3 HBM rating adds robustness.

Use Scenario: Undervoltage detection input for FPGA configuration controller monitoring 27 V auxiliary supply.

IC Role / Device Role / Timing Role: Threshold-setting element feeding comparator input to generate reset signal.

Use Value: Tight 25.65–28.35 V range enables precise trip point definition without external trimming resistors.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX84-C27LT1G	Same 27 V nominal, ±5% tolerance, but SOT-23 package (higher R_JA = 375°C/W); 90 Ω Z_ZT @ 5 mA.	Higher thermal resistance limits continuous power in compact layouts; better suited for low-duty-cycle clamping.	Select when SOT-23 footprint compatibility is required and board-level thermal relief is available.
MMSZ27ET1G	Tighter ±2% tolerance (26.46–27.54 V), same SOD−123 package and 500 mW rating; 75 Ω Z_ZT @ 2 mA.	Improved voltage accuracy enables higher-precision references but at premium cost and reduced availability.	Select when reference stability <±0.5% is mandatory and budget allows tighter-tolerance variant.

Compared with BZX84-C27LT1G and MMSZ27ET1G, the MMSZ27T1 balances cost, thermal performance, and tolerance for general-purpose 24 V system regulation-offering optimal R_JA, proven AEC−Q101 compliance, and broad distributor stock without sacrificing accuracy.

Availability

MMSZ27T1 is available at Aetrix Electronics and suitable for automotive power rail clamping, industrial sensor reference design, and programmable logic supply monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MMSZ27T1 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 semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MMSZ27T1 belongs to the MMSZxxxT1G series of 500 mW Zener regulators designed specifically for high-reliability, surface-mount voltage reference and protection in automotive and industrial systems where AEC−Q101 qualification and tight thermal specifications are mandatory.

FAQ

What is the Zener voltage tolerance of the MMSZ27T1?

The MMSZ27T1 has a nominal Zener voltage of 27 V with a standard tolerance of ±5%, resulting in a guaranteed range of 25.65 V to 28.35 V when measured at I_ZT = 2 mA with 1 ms pulse width. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet (Rev. 13, June 2024). The MMSZ27T1 maintains this specification across its full operating temperature range.

Is the MMSZ27T1 AEC−Q101 qualified?

Yes, the MMSZ27T1 is explicitly AEC−Q101 qualified and PPAP capable, as stated in the Features section of the onsemi datasheet. This qualification covers stress testing for temperature cycling, humidity, mechanical shock, and ESD, making the MMSZ27T1 suitable for automotive applications including engine control units and body electronics where reliability under harsh environmental conditions is critical.

What is the maximum power dissipation of the MMSZ27T1 and how does it derate with temperature?

The MMSZ27T1 is rated for 500 mW total power dissipation on FR−5 board at T_L = 75°C, with linear derating of 6.7 mW/°C above that temperature. Its thermal resistance from junction-to-ambient is 340°C/W, meaning a 1°C rise in ambient temperature reduces usable power by 2.94 mW. This derating behavior is documented in the Maximum Ratings table and Figure 3 (Steady State Power Derating) of the onsemi datasheet.

Does the MMSZ27T1 have Pb−free packaging?

Yes, the MMSZ27T1 is supplied in a Pb−free (RoHS-compliant) package, indicated by the "G" suffix in its full orderable part number MMSZ27T1G. The device uses corrosion-resistant, easily solderable finish and conforms to onsemi's Pb−free strategy, with reflow profile compatibility up to 260°C for 10 seconds. Marking includes "G" or microdot per onsemi's generic SOD−123 marking diagram.

What is the reverse leakage current specification for the MMSZ27T1?

The MMSZ27T1 specifies a maximum reverse leakage current of 0.05 µA at V_R = 18.9 V, as listed in the Electrical Characteristics table on page 3 of the datasheet. This ultra-low leakage supports battery-powered and always-on applications where standby current must be minimized. The value is measured at T_A = 25°C and reflects the device's ability to maintain high impedance below breakdown threshold.

MMSZ27T1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 27 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 80 Ohms

Current - Reverse Leakage @ Vr:: 50 nA @ 18.9 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

MMSZ27T1 FAQ

1.How can I place an order for MMSZ27T1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ27T1 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 MMSZ27T1 reliable?

The price and inventory of MMSZ27T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ27T1 is usually 5 days.

3.What payment methods are accepted for MMSZ27T1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ27T1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ27T1?

MMSZ27T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ27T1 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 MMSZ27T1?

For technical support, including MMSZ27T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ27T1 requirements.

6.How does Aetrix verify that MMSZ27T1 is sourced from the original manufacturer or authorized distributors?

All MMSZ27T1 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 MMSZ27T1 meets industry standards.

7.What is the process for return or replacement of MMSZ27T1?

All MMSZ27T1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ27T1, 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 MMSZ27T1 part is unused and in its original packaging.

Return procedure for MMSZ27T1:

1.Submit a request within 90 days.

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

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