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onsemi MMSZ4678T3G
- Part No.:
- MMSZ4678T3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ4678T3G.pdf
- Description:
- DIODE ZENER 1.8V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:3,657
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Product details
Overview
MMSZ4678T3G from onsemi is a 1.8 V, 500 mW surface-mount Zener diode in SOD−123 package, designed for precision voltage regulation and reference applications with low test current (IZT = 50 µA) and tight voltage tolerance (±5% at 1.8 V nominal). It operates across −55°C to +150°C and delivers stable clamping in low-power biasing, sensor excitation, and analog signal conditioning circuits.
For engineers reviewing the MMSZ4678T3G datasheet, pinout, applications, or equivalent options, key selection criteria include its 1.8 V Zener voltage, 50 µA test current, 7.5 µA leakage at 1 V reverse bias, ESD rating >16 kV (HBM), and SOD−123 thermal resistance (RJL = 150°C/W).
Technical Context
This device functions as a two-terminal voltage reference diode operating in reverse breakdown mode, with nominal Zener voltage of 1.8 V measured at IZT = 50 µA and thermal equilibrium at TL = 30°C ±1°C. Its low IZT enables accurate regulation in ultra-low-current circuits such as battery-powered sensors and microcontroller reset supervision.
The SOD−123 package provides 340°C/W junction-to-ambient thermal resistance on FR−5 board and supports automated placement. With 1.60 × 2.69 × 1.16 mm dimensions and cathode band polarity marking, it meets UL 94 V−0 flammability and Pb−free RoHS compliance requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 1.71–1.89 V @ IZT = 50 µA - ensures precise 1.8 V reference with ±5% tolerance for low-voltage rail monitoring. |
| Power Rating | 500 mW on FR−5 board @ TL = 75°C - supports continuous operation in compact PCB layouts without forced cooling. |
| Leakage Current | 7.5 µA max @ VR = 1 V - minimizes quiescent current draw in always-on sensing nodes. |
| ESD Rating | Class 3 (>16 kV HBM) - protects against handling-induced electrostatic discharge during assembly and field operation. |
| Junction Temp Range | −55°C to +150°C - enables deployment in automotive under-hood, industrial control, and outdoor IoT environments. |
| Package | SOD−123 (Case 425) - 2-pin surface-mount footprint optimized for high-density routing and reflow compatibility. |
Pinout & Package
SOD−123 package: 2-lead, 1.60 × 2.69 × 1.16 mm, void-free thermosetting plastic case with cathode indicated by polarity band. Maximum solder temperature: 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener breakdown terminal | Connected to regulated output node; reverse-biased to maintain fixed voltage drop across load. |
| 2 (Anode) | Reference ground return | Typically tied to system ground or lower-potential rail; completes current path during regulation. |
Key Features
| Feature | Design Value |
|---|---|
| Low IZT operation | 50 µA test current enables stable regulation in µA-level bias networks (e.g., op-amp references). |
| Pb−free & RoHS compliant | Meets global environmental regulations without compromising solderability or long-term reliability. |
| Automated assembly optimized | Standardized SOD−123 footprint and marking support high-yield pick-and-place and AOI inspection. |
| High ESD robustness | Class 3 HBM rating (>16 kV) reduces risk of field failure in unshielded or handheld electronics. |
Applications
| Industrial Sensor Biasing | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) in PLC analog input modules. IC Role / Device Role / Timing Role: Voltage reference diode supplying 1.8 V bias to bridge circuitry with minimal self-heating error. Use Value: Tight 1.8 V tolerance and low 7.5 µA leakage ensure <0.1% measurement drift over temperature and supply variation. |
Use Scenario: Generating clean power-on reset threshold for ARM Cortex-M0+ MCUs in edge gateways. IC Role / Device Role / Timing Role: Zener-clamped voltage divider sets reliable 1.8 V reset trip point independent of VDD ramp rate. Use Value: Low IZT (50 µA) allows use with high-value pull-up resistors, reducing standby current below 1 µA. |
| Low-Power Analog Front-End | Automotive Cabin Control Panel |
Use Scenario: Establishing reference voltage for 12-bit SAR ADCs in battery-operated gas monitors. IC Role / Device Role / Timing Role: Precision shunt reference stabilizing ADC reference rail against supply ripple and temperature drift. Use Value: −55°C to +150°C operating range and 150°C/W RJL enable direct mounting near heat-generating components without derating. |
Use Scenario: Overvoltage protection and level-shifting for LIN bus transceivers in HVAC control units. IC Role / Device Role / Timing Role: Clamping diode limiting transient spikes to 1.8 V to protect 2.0 V tolerant I/O pins. Use Value: AEC−Q101 qualification and PPAP capability confirm suitability for automotive production environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C1V8 | 1.8 V ±5%, 300 mW rating, SOD-323 package, IZT = 5 µA | Lower power rating and smaller package reduce thermal margin in sustained 10 mA loads. | Select when board space is constrained and peak dissipation remains <300 mW. |
| MMBZ5221BS | 1.8 V ±5%, 350 mW rating, SOT-23 package, IZT = 20 µA | Higher IZT requires larger bias resistor, increasing sensitivity to supply variation. | Prefer where existing SOT-23 footprints exist and thermal load is moderate. |
Compared with BZX584C1V8 and MMBZ5221BS, the MMSZ4678T3G offers superior thermal performance (500 mW rating, RJL = 150°C/W) and lower leakage (7.5 µA @ 1 V), making it optimal for high-reliability, low-quiescent-current designs where SOD−123 layout is acceptable.
Availability
MMSZ4678T3G is available at Aetrix Electronics and suitable for industrial sensor biasing, microcontroller reset circuits, and low-power analog front-end designs requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for MMSZ4678T3G 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 MMSZ4xxxT3G series belongs to onsemi's precision Zener regulator family, engineered specifically for low-IZT, high-stability voltage reference and clamping in space-constrained, thermally demanding environments.
FAQ
What is the exact Zener voltage tolerance of MMSZ4678T3G at 25°C?
The MMSZ4678T3G has a specified Zener voltage range of 1.71 V to 1.89 V at IZT = 50 µA and TL = 30°C ±1°C, corresponding to a ±5% tolerance around the nominal 1.8 V value. This tolerance is guaranteed per onsemi's Electrical Characteristics table and applies under standard test conditions defined in the datasheet.
Can MMSZ4678T3G be used in automotive applications?
Yes, the MMSZ4678T3G is AEC−Q101 qualified and PPAP capable, confirming its suitability for automotive applications including cabin control, body electronics, and powertrain subsystems. Its −55°C to +150°C operating range and Class 3 ESD rating further support under-hood and infotainment use cases.
What is the maximum reverse leakage current for MMSZ4678T3G at 1 V bias?
The MMSZ4678T3G exhibits a maximum reverse leakage current (IR) of 7.5 µA when biased at VR = 1 V, as specified in the Electrical Characteristics table on page 3 of the onsemi datasheet. This low leakage supports ultra-low-power operation in always-on monitoring circuits.
How does the SOD−123 package of MMSZ4678T3G affect thermal performance?
The SOD−123 package of MMSZ4678T3G provides a junction-to-lead thermal resistance (RJL) of 150°C/W and junction-to-ambient (RJA) of 340°C/W on FR−5 board. This enables reliable 500 mW operation up to 75°C lead temperature, with linear derating beyond that point-critical for thermally dense PCB layouts.
Is MMSZ4678T3G compatible with lead-free reflow soldering processes?
Yes, MMSZ4678T3G is Pb−free and RoHS compliant, rated for peak reflow temperatures up to 260°C for 10 seconds. Its corrosion-resistant finish and void-free molded case ensure robust solder joint formation and long-term interconnect reliability under IPC-J-STD-020-compliant profiles.
MMSZ4678T3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 1.8 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- 7.5 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
MMSZ4678T3G FAQ
1.How can I place an order for MMSZ4678T3G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ4678T3G 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 MMSZ4678T3G reliable?
The price and inventory of MMSZ4678T3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ4678T3G is usually 5 days.
3.What payment methods are accepted for MMSZ4678T3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ4678T3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ4678T3G?
MMSZ4678T3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ4678T3G 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 MMSZ4678T3G?
For technical support, including MMSZ4678T3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ4678T3G requirements.
6.How does Aetrix verify that MMSZ4678T3G is sourced from the original manufacturer or authorized distributors?
All MMSZ4678T3G 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 MMSZ4678T3G meets industry standards.
7.What is the process for return or replacement of MMSZ4678T3G?
All MMSZ4678T3G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ4678T3G, 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 MMSZ4678T3G part is unused and in its original packaging.
Return procedure for MMSZ4678T3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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