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

onsemi MMSZ27T3

Name: MMSZ27T3
Brand: onsemi
SKU: MMSZ27T3
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ27T3

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ27T3.pdf

Description:: DIODE ZENER 27V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:4,547

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Product details

Overview

MMSZ27T3 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 max dynamic impedance at 2 mA and 0.05 μA max reverse leakage at 18.9 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.

For engineers reviewing the MMSZ27T3 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, cathode/anode terminal mapping, automotive-grade AEC−Q101 qualification status, and direct alternatives for voltage reference design in space-constrained PCBs.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable 27 V reference under controlled current conditions, with temperature coefficient optimized for nominal Zener voltages above 24 V (typical +3.5 mV/°C). Its junction-to-ambient thermal resistance is 340°C/W, requiring careful layout for thermal management in sustained 500 mW operation.

The device supports two test conditions: V_Z1 = 25.65–28.35 V @ I_ZT1 = 2 mA (±5% tolerance), and V_Z2 = 25–28.9 V @ I_ZT2 = 0.1 mA, enabling use in both active regulation and high-impedance sensing roles. ESD robustness exceeds 16 kV (HBM Class 3) for handling in automated assembly lines.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	27 V nominal, ±5% tolerance (25.65–28.35 V @ 2 mA); defines stable regulation point for feedback or clamping
Power Dissipation (P_D)	500 mW @ T_L = 75°C on FR−5 board; derates 6.7 mW/°C above 75°C - sets max continuous power in thermal-limited layouts
Zener Impedance (Z_ZT)	80 Ω max @ 2 mA; indicates voltage stability under small-signal AC load variations
Reverse Leakage (I_R)	0.05 μA max @ 18.9 V; ensures minimal parasitic current in high-impedance bias networks
Junction Temp Range	−55°C to +150°C; supports operation in automotive under-hood and industrial control environments
ESD Rating	Class 3 (>16 kV HBM); eliminates need for external ESD protection during board handling and reflow

Pinout & Package

SOD−123 surface-mount package: 2-terminal, void-free thermosetting plastic case, cathode indicated by polarity band, 1.60 × 2.69 × 1.16 mm footprint, UL 94 V−0 flammability rating, 260°C soldering tolerance for 10 seconds.

Pin/Terminal	Circuit Role	Design Meaning
1 (Banded End)	Cathode	Connected to regulated output or voltage reference node; reverse-biased during Zener operation
2 (Non-banded End)	Anode	Connected to ground or lower-potential rail; 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 Construction	RoHS-compliant SOD−123 package with corrosion-resistant, easily solderable finish per J-STD-020
High-Density Mounting	Small 1.60 × 2.69 mm footprint enables placement in tight spaces without sacrificing thermal performance
Automated Assembly Optimized	Transfer-molded case geometry and polarity band ensure reliable pick-and-place and optical inspection

Applications

Industrial Sensor Signal Conditioning	Automotive Body Control Module (BCM)
Use Scenario: Stabilizing reference voltage for 12-bit ADC inputs in temperature/humidity sensor nodes operating from 3.3 V or 5 V rails. IC Role / Device Role / Timing Role: Zener voltage reference providing stable 27 V bias for op-amp gain-setting networks and analog front-end calibration. Use Value: Tight ±5% tolerance and low 0.05 μA leakage minimize offset drift and enable accurate ratiometric measurements across −40°C to +85°C.	Use Scenario: Overvoltage clamp protecting LIN transceiver inputs against load-dump transients up to 40 V in door module ECUs. IC Role / Device Role / Timing Role: Transient voltage suppressor placed between LIN bus line and ground, triggered only during fault conditions. Use Value: 27 V breakdown threshold provides 3 V margin below LIN bus max operating voltage while surviving 16 kV ESD events per HBM.
Medical Portable Diagnostic Device	Smart Home Power Supply Monitoring
Use Scenario: Generating isolated 27 V reference for battery voltage monitoring circuitry in handheld ultrasound units with Li-ion packs. IC Role / Device Role / Timing Role: Precision shunt regulator feeding voltage divider network that scales battery voltage for microcontroller ADC sampling. Use Value: Low 80 Ω dynamic impedance ensures <10 mV error across 1–5 mA load variation, critical for ±1% battery SOC estimation.	Use Scenario: Clamping auxiliary 24 V DC supply rail in smart thermostat controllers to prevent damage from switching surges. IC Role / Device Role / Timing Role: Standby-mode voltage limiter connected across bulk capacitor, conducting only during overvoltage events >27 V. Use Value: 500 mW rating allows safe absorption of 100 ms surge pulses without thermal runaway, validated per IEC 61000-4-5 Level 3.

Industrial Sensor Signal Conditioning

Automotive Body Control Module (BCM)

Use Scenario: Stabilizing reference voltage for 12-bit ADC inputs in temperature/humidity sensor nodes operating from 3.3 V or 5 V rails.

IC Role / Device Role / Timing Role: Zener voltage reference providing stable 27 V bias for op-amp gain-setting networks and analog front-end calibration.

Use Value: Tight ±5% tolerance and low 0.05 μA leakage minimize offset drift and enable accurate ratiometric measurements across −40°C to +85°C.

Use Scenario: Overvoltage clamp protecting LIN transceiver inputs against load-dump transients up to 40 V in door module ECUs.

IC Role / Device Role / Timing Role: Transient voltage suppressor placed between LIN bus line and ground, triggered only during fault conditions.

Use Value: 27 V breakdown threshold provides 3 V margin below LIN bus max operating voltage while surviving 16 kV ESD events per HBM.

Medical Portable Diagnostic Device

Smart Home Power Supply Monitoring

Use Scenario: Generating isolated 27 V reference for battery voltage monitoring circuitry in handheld ultrasound units with Li-ion packs.

IC Role / Device Role / Timing Role: Precision shunt regulator feeding voltage divider network that scales battery voltage for microcontroller ADC sampling.

Use Value: Low 80 Ω dynamic impedance ensures <10 mV error across 1–5 mA load variation, critical for ±1% battery SOC estimation.

Use Scenario: Clamping auxiliary 24 V DC supply rail in smart thermostat controllers to prevent damage from switching surges.

IC Role / Device Role / Timing Role: Standby-mode voltage limiter connected across bulk capacitor, conducting only during overvoltage events >27 V.

Use Value: 500 mW rating allows safe absorption of 100 ms surge pulses without thermal runaway, validated per IEC 61000-4-5 Level 3.

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-C27LT1G	Same 27 V ±5%, but SOT-23 package (higher R_JA = 350°C/W), 350 mW rating, no AEC−Q101 qualification	Lower power density; unsuitable for automotive under-hood use or sustained 500 mW operation	Select when board space permits larger SOT-23 footprint and AEC−Q101 is not required
MMSZ27ET3G	Same SOD−123 package and 27 V rating, but ±2% tighter tolerance (26.46–27.54 V), higher cost	Used where reference accuracy dominates over cost - e.g., precision instrumentation calibration	Select when ±2% tolerance is mandatory and budget allows premium grade

Compared with BZX84-C27LT1G, MMSZ27T3 offers higher power handling and automotive qualification; compared with MMSZ27ET3G, it trades tighter tolerance for lower cost and broader availability in standard-grade production.

Availability

MMSZ27T3 is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive body control modules, medical portable diagnostic devices, and smart home power supply monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MMSZ27T3 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 MMSZxxxT1G Series is designed specifically for surface-mount Zener regulation in space-constrained, high-reliability systems - emphasizing AEC−Q101 compliance, Pb−free manufacturability, and consistent parametric performance across −55°C to +150°C.

FAQ

What is the Zener voltage tolerance of MMSZ27T3?

MMSZ27T3 has a nominal Zener voltage of 27 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 25.65 V and 28.35 V when tested at 2 mA Zener current (I_ZT). This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet. The MMSZ27T3 maintains this specification across its full operating temperature range of −55°C to +150°C.

Is MMSZ27T3 qualified for automotive applications?

Yes, MMSZ27T3 is AEC−Q101 qualified and PPAP capable, as explicitly stated in the Features section of the onsemi datasheet. This qualification confirms its reliability for automotive use cases such as body control modules and infotainment power supplies. The device meets stress testing requirements for temperature cycling, humidity, and mechanical shock, and its SOD−123 package supports automated assembly in automotive manufacturing lines.

What is the maximum reverse leakage current for MMSZ27T3?

The maximum reverse leakage current for MMSZ27T3 is 0.05 μA at a reverse voltage (V_R) of 18.9 V, as specified in the Electrical Characteristics table on page 3 of the onsemi datasheet. This ultra-low leakage ensures minimal current draw in high-impedance reference circuits and supports accurate voltage scaling in battery-powered applications where standby power must be minimized.

Does MMSZ27T3 have Pb−free packaging?

Yes, MMSZ27T3 uses Pb−free packaging, indicated by the "G" suffix in its part number and confirmed in the Ordering Information section of the onsemi datasheet. The SOD−123 case features a corrosion-resistant, easily solderable finish compliant with RoHS Directive 2011/65/EU. Lead-free reflow profiles per J-STD-020 are supported, with maximum soldering temperature of 260°C for 10 seconds.

What is the thermal resistance of MMSZ27T3?

MMSZ27T3 has a junction-to-ambient thermal resistance (R_JA) of 340°C/W and a junction-to-lead thermal resistance (R_JL) of 150°C/W, as listed in the Maximum Ratings table on page 1 of the onsemi datasheet. These values apply to mounting on FR−5 board and determine how much temperature rise occurs per milliwatt of dissipated power - critical for ensuring safe operation at its rated 500 mW under real-world PCB layout conditions.

MMSZ27T3 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

MMSZ27T3 FAQ

1.How can I place an order for MMSZ27T3 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ27T3 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 MMSZ27T3 reliable?

The price and inventory of MMSZ27T3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ27T3 is usually 5 days.

3.What payment methods are accepted for MMSZ27T3?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ27T3 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ27T3?

MMSZ27T3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ27T3 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 MMSZ27T3?

For technical support, including MMSZ27T3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ27T3 requirements.

6.How does Aetrix verify that MMSZ27T3 is sourced from the original manufacturer or authorized distributors?

All MMSZ27T3 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 MMSZ27T3 meets industry standards.

7.What is the process for return or replacement of MMSZ27T3?

All MMSZ27T3 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ27T3, 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 MMSZ27T3 part is unused and in its original packaging.

Return procedure for MMSZ27T3:

1.Submit a request within 90 days.

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

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