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onsemi MMSZ39T1
- Part No.:
- MMSZ39T1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ39T1.pdf
- Description:
- DIODE ZENER 39V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:9,962
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Product details
Overview
MMSZ39T1G from onsemi is a 39 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C, with 130 Ω dynamic impedance at 2 mA test current and 0.05 μA reverse leakage at 27.3 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog sensor interfaces and power supply feedback networks.
For engineers reviewing the MMSZ39T1G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, AEC−Q101 qualification status, and direct alternatives for automotive-grade voltage regulation design.
Technical Context
This device operates as a two-terminal silicon Zener diode optimized for stable reverse-biased breakdown at nominal 39 V. Its 130 Ω Zener impedance (ZZT) at IZT = 2 mA and temperature coefficient near +3.5 mV/°C (per typical curve for 39 V devices) support predictable regulation under varying load and thermal conditions.
Designed for surface-mount assembly on FR−4/FR−5 PCBs, it features Class 3 ESD robustness (>16 kV HBM), UL 94 V−0 flammability rating, and Pb−free construction compliant with RoHS. The SOD−123 case provides 150°C/W junction-to-lead thermal resistance and supports reflow soldering up to 260°C for 10 seconds.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05 V min / 39 V nom / 40.95 V max at IZT = 2 mA - defines regulated output range under standard test conditions |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - sets maximum steady-state power handling before thermal derating begins |
| Zener Impedance (ZZT) | 130 Ω max at IZT = 2 mA - determines regulation accuracy under small-signal AC load variations |
| Reverse Leakage (IR) | 0.05 μA max at VR = 27.3 V - ensures minimal quiescent current in high-impedance bias networks |
| Junction Temp Range | −55°C to +150°C - enables operation in under-hood automotive and industrial environments |
| ESD Rating | Class 3 (>16 kV) per HBM - protects against electrostatic discharge during board handling and assembly |
Pinout & Package
SOD−123 plastic surface-mount package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant finish; cathode indicated by polarity band; lead-free (Pb−free) construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener breakdown terminal | Connected to regulated voltage node; reverse-biased during normal operation |
| 2 (Anode) | Reference/ground terminal | Typically tied to circuit ground or lower-potential rail; completes Zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualified | Validated for automotive electronics use with PPAP capability and controlled change management |
| 500 mW FR−5 rating | Enables compact voltage reference design without external heat sinking in standard PCB layouts |
| ±5% VZ tolerance | Supports cost-effective production without post-assembly trimming in non-critical regulation applications |
| UL 94 V−0 flammability | Meets safety standards for enclosed industrial and transportation equipment enclosures |
Applications
| Automotive Sensor Signal Conditioning | Industrial PLC Input Protection |
|---|---|
Use Scenario: Stabilizing reference voltage for analog front-end circuits in engine coolant temperature sensors. IC Role / Device Role / Timing Role: Zener diode providing precise 39 V clamping and biasing for op-amp input protection and ADC reference scaling. Use Value: Maintains signal integrity across −40°C to +125°C ambient while meeting AEC−Q101 reliability requirements. | Use Scenario: Overvoltage protection for 24 V DC digital input modules exposed to inductive switching transients. IC Role / Device Role / Timing Role: Fast-acting shunt regulator absorbing surge energy above 39 V to protect downstream logic inputs. Use Value: Limits transient voltage to safe levels with <0.05 μA leakage at operating voltage, minimizing standby power loss. |
| Medical Instrument Power Monitoring | Consumer IoT Battery Management |
Use Scenario: Reference generation for isolated DC−DC converter feedback in portable ultrasound units. IC Role / Device Role / Timing Role: Precision Zener establishing stable 39 V reference for optocoupler-based voltage sensing loop. Use Value: Delivers <130 Ω dynamic impedance and ±5% tolerance to ensure tight output regulation under variable load. | Use Scenario: Voltage threshold detection in lithium-ion battery pack protection ICs monitoring cell stack overvoltage. IC Role / Device Role / Timing Role: Clamping element in comparator-based overvoltage latch circuit triggered at ~39 V. Use Value: Provides repeatable trip point with minimal temperature drift (typ. +3.5 mV/°C) across battery operating range. |
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-C39 | Same 39 V nominal Zener voltage, but SOT−23 package (higher thermal resistance: RJA = 350°C/W vs. 340°C/W); 500 mW rating at 25°C only | Less suitable for high-temperature PCB locations due to inferior thermal performance and no AEC−Q101 qualification | Select BZX84-C39 only for cost-sensitive consumer designs where automotive qualification and thermal margin are not required |
| SZMM3Z39T1G | Identical 39 V ±5% spec, same SOD−123 package, but includes SZ prefix denoting automotive-specific traceability and control change requirements | Required for Tier 1 automotive programs mandating PPAP documentation and site-controlled manufacturing | Choose SZMM3Z39T1G when full AEC−Q101 compliance with documented process controls is contractually mandated |
Compared with MMSZ39T1G, BZX84-C39 offers lower cost but reduced thermal reliability and no automotive qualification, while SZMM3Z39T1G adds traceability overhead without electrical benefit-making MMSZ39T1G the optimal balance of performance, qualification, and procurement flexibility for general-purpose industrial and automotive-adjacent designs.
Availability
MMSZ39T1G is available at Aetrix Electronics and suitable for automotive sensor conditioning, industrial PLC input protection, and medical instrument power monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MMSZ39T1G 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 supplier of energy-efficient semiconductor solutions, serving automotive, industrial, cloud, and IoT markets with a focus on reliability and sustainability.
The MMSZxxxT1G series was developed to deliver AEC−Q101-qualified, space-efficient Zener regulation in SOD−123 for automotive body electronics, sensor interfaces, and industrial control systems demanding high thermal stability and ESD robustness.
FAQ
What is the nominal Zener voltage and tolerance of MMSZ39T1G?
MMSZ39T1G has a nominal Zener voltage of 39 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 37.05 V and 40.95 V when tested at IZT = 2 mA and TA = 25°C. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet.
Is MMSZ39T1G qualified for automotive applications?
Yes, MMSZ39T1G is AEC−Q101 qualified and PPAP capable, as explicitly stated in the Features section of the onsemi datasheet. It meets automotive reliability requirements including temperature cycling, humidity testing, and mechanical shock, making it suitable for under-hood and cabin electronics.
What is the maximum power dissipation of MMSZ39T1G and how does it derate with temperature?
MMSZ39T1G is rated for 500 mW total power dissipation on FR−5 board at TL = 75°C, with linear derating of 6.7 mW/°C above that temperature. This derating behavior is defined in the Maximum Ratings table and illustrated in Figure 3 (Steady State Power Derating) of the datasheet.
Does MMSZ39T1G have ESD protection, and what level is specified?
MMSZ39T1G has an ESD rating of Class 3 (>16 kV) per the Human Body Model (HBM), as listed in the Features section. This level of robustness ensures reliable handling during automated PCB assembly and field service without requiring additional ESD mitigation circuitry.
What is the reverse leakage current specification for MMSZ39T1G at its rated voltage?
MMSZ39T1G specifies a maximum reverse leakage current of 0.05 μA at VR = 27.3 V, as shown in the Electrical Characteristics table on page 3. This low leakage supports high-impedance bias networks and minimizes standby power consumption in always-on systems.
MMSZ39T1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 130 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 27.3 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
MMSZ39T1 FAQ
1.How can I place an order for MMSZ39T1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ39T1 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 MMSZ39T1 reliable?
The price and inventory of MMSZ39T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ39T1 is usually 5 days.
3.What payment methods are accepted for MMSZ39T1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ39T1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ39T1?
MMSZ39T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ39T1 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 MMSZ39T1?
For technical support, including MMSZ39T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ39T1 requirements.
6.How does Aetrix verify that MMSZ39T1 is sourced from the original manufacturer or authorized distributors?
All MMSZ39T1 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 MMSZ39T1 meets industry standards.
7.What is the process for return or replacement of MMSZ39T1?
All MMSZ39T1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ39T1, 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 MMSZ39T1 part is unused and in its original packaging.
Return procedure for MMSZ39T1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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