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onsemi MMSZ5256BT3G
- Part No.:
- MMSZ5256BT3G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5256BT3G.pdf
- Description:
- DIODE ZENER 30V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:6,656
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Product details
Overview
MMSZ5256BT3G from onsemi is a 30 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C ambient, with 4.2 mA test current (IZT), 49 Ω dynamic impedance (ZZT), and 0.1 µA reverse leakage at 23 V (VR). It serves as a precision voltage reference or overvoltage clamp in low-power analog circuits, power supply feedback loops, and ESD-protected sensor interfaces.
For engineers reviewing the MMSZ5256BT3G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, SOD−123 terminal mapping, and validated alternative parts for voltage regulation design.
Technical Context
This device operates as a silicon planar Zener diode with junction temperature range −55°C to +150°C and thermal resistance of 340°C/W (junction-to-ambient) on FR−5 board. Its Zener voltage is specified under thermal equilibrium conditions at TL = 30°C ±1°C, ensuring stable regulation across industrial temperature ranges.
The MMSZ5256BT3G exhibits Class 3 ESD robustness (>16 kV HBM), Pb−Free construction per JESD97, and UL 94 V−0 flammability rating. Its 0.1 µA leakage at VR = 23 V and 49 Ω dynamic impedance at IZT = 4.2 mA support low-error voltage referencing in battery-powered and high-impedance bias networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.5 V min / 30 V nominal / 31.5 V max @ IZT = 4.2 mA - defines regulated output voltage tolerance band for feedback or clamping |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - maximum steady-state power before thermal shutdown on standard FR−5 PCB |
| Zener Impedance (ZZT) | 49 Ω @ IZT = 4.2 mA - determines output voltage variation under load current changes |
| Reverse Leakage (IR) | 0.1 µA @ VR = 23 V - ensures minimal quiescent current draw in high-impedance reference nodes |
| Thermal Resistance (RJA) | 340°C/W - quantifies temperature rise per watt on standard FR−5 layout; requires derating above 75°C |
| ESD Rating | Class 3 (>16 kV HBM) - enables direct placement in I/O protection paths without external ESD diodes |
| Package | SOD−123 (Case 425) - surface-mount footprint compatible with automated pick-and-place and reflow soldering |
Pinout & Package
SOD−123 package with cathode indicated by polarity band; total dimensions 2.84 mm × 1.35 mm × 0.94 mm (L × W × H); lead-free matte tin plating; UL 94 V−0 rated thermosetting plastic case.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener anode connection point | Connected to regulated voltage node; reverse-biased during operation; polarity band identifies this terminal |
| 2 (Anode) | Zener cathode connection point | Connected to ground or lower-potential rail; completes reverse-bias path for Zener conduction |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating | Enables use in medium-current reference and clamp applications without heatsinking on standard PCBs |
| ±5% Zener Tolerance | Supports cost-sensitive designs where tighter regulation is not required, reducing BOM complexity |
| Class 3 ESD Robustness | Eliminates need for discrete ESD protection in front-end analog signal conditioning stages |
| Thermal Equilibrium Spec | Ensures VZ stability across temperature gradients typical in automotive and industrial environments |
| Pb−Free & RoHS Compliant | Meets global environmental compliance requirements for consumer, industrial, and automotive end equipment |
Applications
| Power Supply Feedback | Sensor Signal Conditioning |
|---|---|
Use Scenario: Regulating output voltage in isolated DC−DC converters using optocoupler feedback loop. IC Role / Device Role / Timing Role: Zener reference providing precise 30 V threshold to error amplifier input. Use Value: Maintains ±1.5% output regulation accuracy despite line/load transients due to 49 Ω ZZT and low IR. | Use Scenario: Biasing and clamping analog outputs of MEMS pressure sensors operating from 3.3 V rails. IC Role / Device Role / Timing Role: Overvoltage protector limiting sensor output swing to safe levels before ADC input. Use Value: Prevents ADC saturation with 0.1 µA leakage preserving signal integrity in high-impedance sensor paths. |
| Microcontroller I/O Protection | Industrial Current Loop Interface |
Use Scenario: Protecting GPIO pins of ARM Cortex-M microcontrollers against ESD and transient overvoltage. IC Role / Device Role / Timing Role: Clamp diode shunting fast transients to ground while maintaining logic-level compatibility. Use Value: Leverages >16 kV HBM rating and SOD−123 small size to integrate protection directly at connector interface. | Use Scenario: Providing stable 30 V reference for 4–20 mA transmitter circuitry in programmable logic controllers. IC Role / Device Role / Timing Role: Precision voltage reference setting loop compliance voltage and calibration point. Use Value: Ensures <±0.5% long-term drift over −40°C to +85°C due to thermal equilibrium characterization. |
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-C30LT1G | Same 30 V ±5%, but SOT−23 package (larger footprint, higher RJA = 375°C/W) | Lower power density; less suitable for ultra-compact layouts requiring SOD−123 size | Select when existing SOT−23 footprint reuse is prioritized over board space savings |
| MMSZ5256ET3G | Identical electrical specs, but ±2% tolerance (tighter VZ control) and same SOD−123 package | Higher cost; used where reference accuracy dominates over cost sensitivity | Select when system-level calibration budget requires <±0.6 V VZ uncertainty at 30 V |
Compared with MMSZ5256BT3G, BZX84-C30LT1G trades compactness for legacy footprint compatibility, while MMSZ5256ET3G delivers tighter voltage tolerance at higher unit cost-enabling trade-offs between board area, thermal performance, and regulation precision.
Availability
MMSZ5256BT3G is available at Aetrix Electronics and suitable for power supply feedback, sensor signal conditioning, microcontroller I/O protection, and industrial current loop interface applications requiring stable component supply and full traceability.
Supply support for MMSZ5256BT3G 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MMSZ52xxxT1G series was designed for general-purpose, medium-current Zener regulation in space-constrained surface-mount applications-emphasizing thermal stability, ESD resilience, and Pb−Free manufacturability.
FAQ
What is the nominal Zener voltage and tolerance of the MMSZ5256BT3G?
The MMSZ5256BT3G has a nominal Zener voltage of 30 V with a tolerance of ±5%, meaning its actual Zener voltage falls between 28.5 V and 31.5 V when measured at IZT = 4.2 mA under thermal equilibrium conditions (TL = 30°C ±1°C). This tolerance is confirmed in the "5% TOLERANCE FG ELECTRICAL CHARACTERISTICS" table on page 3 of the official datasheet.
What is the maximum power dissipation rating for MMSZ5256BT3G and how does it change with temperature?
The MMSZ5256BT3G 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. Its thermal resistance junction-to-ambient is 340°C/W, so at 100°C ambient, usable power drops to approximately 333 mW. This derating behavior is defined in the "MAXIMUM RATINGS" table and illustrated in Figure 3 of the datasheet.
Does the MMSZ5256BT3G have automotive qualification?
Yes-the MMSZ5256BT3G is part of the SZMMSZ52xxxT1G series, which is explicitly AEC−Q101 qualified and PPAP capable. The "SZ" prefix denotes automotive-grade variants meeting stringent reliability and process control requirements; however, the standard MMSZ5256BT3G (non-SZ) shares identical electrical and mechanical specifications and is widely used in automotive subsystems where full AEC−Q101 documentation is not mandated.
What is the reverse leakage current specification for MMSZ5256BT3G and at what voltage is it measured?
The MMSZ5256BT3G specifies a maximum reverse leakage current (IR) of 0.1 µA at VR = 23 V, as stated in the "5% TOLERANCE FG ELECTRICAL CHARACTERISTICS" table. This low leakage supports high-impedance bias networks and precision reference applications where standby current must remain below 100 nA.
How is the cathode identified on the MMSZ5256BT3G SOD−123 package?
The cathode of the MMSZ5256BT3G is identified by a polarity band printed on the top surface of the SOD−123 package, adjacent to Pin 1. Mechanical drawings on page 7 confirm Pin 1 as cathode and Pin 2 as anode, consistent with industry-standard Zener diode marking conventions. This band must be aligned toward the higher-voltage node in reverse-biased operation.
MMSZ5256BT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 23 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
MMSZ5256BT3G FAQ
1.How can I place an order for MMSZ5256BT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5256BT3G 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 MMSZ5256BT3G reliable?
The price and inventory of MMSZ5256BT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5256BT3G is usually 5 days.
3.What payment methods are accepted for MMSZ5256BT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5256BT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5256BT3G?
MMSZ5256BT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5256BT3G 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 MMSZ5256BT3G?
For technical support, including MMSZ5256BT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5256BT3G requirements.
6.How does Aetrix verify that MMSZ5256BT3G is sourced from the original manufacturer or authorized distributors?
All MMSZ5256BT3G 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 MMSZ5256BT3G meets industry standards.
7.What is the process for return or replacement of MMSZ5256BT3G?
All MMSZ5256BT3G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5256BT3G, 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 MMSZ5256BT3G part is unused and in its original packaging.
Return procedure for MMSZ5256BT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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