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onsemi MMSZ5256BT1
- Part No.:
- MMSZ5256BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5256BT1.pdf
- Description:
- DIODE ZENER 30V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:4,397
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Product details
Overview
MMSZ5256BT1 from ON Semiconductor is a 30 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation on FR−5 board at 75°C, 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 and digital supply regulation circuits.
For engineers reviewing the MMSZ5256BT1 datasheet, pinout, applications, or equivalent options, this device is selected for stable 30 V reference generation in space-constrained consumer, industrial, and automotive subsystems where thermal equilibrium Zener voltage accuracy and Class 3 ESD robustness (>16 kV HBM) are required.
Technical Context
This Zener regulator operates with junction-to-ambient thermal resistance of 340°C/W and junction-to-lead resistance of 150°C/W, enabling reliable operation across −55°C to +150°C ambient range. Its 30 V nominal Zener voltage is specified under thermal equilibrium conditions at TL = 30°C ±1°C, ensuring stable reference performance independent of transient self-heating.
The device exhibits 0.25 V forward voltage maximum at 10 mA forward current and maintains ≤600 Ω Zener impedance at knee current (IZK), supporting consistent clamping behavior across load and temperature variations in feedback and protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.5–31.5 V @ IZT = 4.2 mA - defines precise 30 V regulation window for reference or clamp function |
| Power Dissipation (PD) | 500 mW on FR−5 board @ TL = 75°C - sets maximum continuous power handling in standard PCB layout |
| Zener Impedance (ZZT) | 49 Ω @ IZT = 4.2 mA - determines output voltage stability under varying load current |
| Reverse Leakage (IR) | 0.1 µA @ VR = 23 V - ensures minimal quiescent current in standby or high-impedance bias networks |
| ESD Rating | Class 3 (>16 kV) per HBM - provides robustness against electrostatic discharge during handling and assembly |
| Junction Temp Range | −55°C to +150°C - supports operation in extended-temperature automotive and industrial environments |
Pinout & Package
SOD−123 surface-mount plastic package (Case 425, Style 1), void-free thermosetting construction, cathode indicated by polarity band, UL 94 V−0 flammability rating, and 260°C/10 sec maximum soldering temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener anode connection point | Connected to regulated voltage node; reverse-biased operation requires cathode at higher potential than anode |
| 2 (Anode) | Zener cathode connection point | Typically tied to ground or lower-potential rail; completes reverse-bias path for Zener conduction |
Key Features
| Feature | Design Value |
|---|---|
| Thermal-equilibrium Zener voltage spec | Ensures 30 V nominal value is measured at stable junction temperature (TL = 30°C ±1°C), eliminating self-heating drift in precision references |
| Pb−Free SOD−123 packaging | Meets RoHS compliance and enables lead-free reflow soldering without reliability compromise |
| Automated assembly optimized footprint | Standardized pad layout per ON Semiconductor SOD−123 soldering footprint supports high-yield pick-and-place and reflow processes |
| High-density small outline | 1.8 mm × 2.8 mm body size allows placement in compact power management and sensor interface PCBs |
Applications
| USB Power Delivery Clamp | Industrial Sensor Bias Reference |
|---|---|
Use Scenario: Clamping transient overvoltage on USB 3.0 VBUS line during hot-plug events or ESD strikes. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to shunt excess energy and hold voltage below 33 V. Use Value: Prevents damage to downstream USB controller ICs by limiting peak voltage to within 10% of 30 V nominal rating. | Use Scenario: Providing stable 30 V bias voltage for piezoresistive pressure sensor excitation in factory automation modules. IC Role / Device Role / Timing Role: Precision voltage reference source maintaining constant current through sensor bridge. Use Value: Enables <±0.5% full-scale measurement accuracy by minimizing Zener voltage drift over −40°C to +85°C operating range. |
| Automotive Body Control Module Regulator | IoT Node Battery Monitor Reference |
Use Scenario: Generating local 30 V rail for CAN transceiver bias in 12 V vehicle electrical systems. IC Role / Device Role / Timing Role: Zener-based shunt regulator supplying clean, low-noise voltage to isolated CAN PHY circuitry. Use Value: Maintains CAN signal integrity by reducing supply ripple to <50 mVpp, meeting ISO 11898-2 EMC requirements. | Use Scenario: Acting as threshold detector in lithium-ion battery pack voltage monitoring circuit. IC Role / Device Role / Timing Role: Reverse-biased Zener triggering comparator when cell stack reaches 30 V cutoff level. Use Value: Delivers accurate overvoltage trip point with <±1.5 V tolerance across 10-year field life due to AEC−Q101 qualification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584-C30 | 30 V ±5%, 300 mW rating, SOD-323 package, 70 Ω ZZT @ 5 mA | Lower power handling and higher dynamic impedance limit use in higher-current regulation | Select when board space is tighter (SOD-323 vs SOD-123) and 300 mW suffices |
| 1N4749A | 30 V ±5%, 1 W rating, DO-41 through-hole package, 35 Ω ZZT @ 15 mA | Through-hole mounting and higher power require different PCB layout and thermal design | Select for legacy through-hole designs or where >500 mW surge capability is needed |
Compared with MMSZ5256BT1, BZX584-C30 offers smaller footprint but reduced power and higher impedance, while 1N4749A provides higher power and lower impedance at the cost of through-hole assembly and larger board area-making MMSZ5256BT1 optimal for modern SMT designs requiring 500 mW and 30 V precision in minimal area.
Availability
MMSZ5256BT1 is available at Aetrix Electronics and suitable for USB power protection, industrial sensor biasing, automotive body control modules, IoT battery monitoring, and general-purpose voltage reference applications requiring stable component supply and AEC−Q101 qualified performance.
Supply support for MMSZ5256BT1 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MMSZ5256BT1 belongs to the MMSZ52xxxT1G Zener regulator family, designed for high-reliability, surface-mount voltage reference and clamping in space-constrained, thermally demanding applications across automotive and industrial segments.
FAQ
What is the nominal Zener voltage and tolerance of the MMSZ5256BT1?
The MMSZ5256BT1 has a nominal Zener voltage of 30 V with a ±5% tolerance, meaning its actual reverse breakdown voltage falls between 28.5 V and 31.5 V when tested at IZT = 4.2 mA under thermal equilibrium conditions (TL = 30°C ±1°C). This specification is confirmed in the Electrical Characteristics table on page 3 of the official ON Semiconductor datasheet for the MMSZ52xxxT1G series.
What is the maximum power dissipation rating for the MMSZ5256BT1 and under what conditions?
The MMSZ5256BT1 is rated for 500 mW total power dissipation on an FR−5 board at a lead temperature (TL) of 75°C, with derating of 6.7 mW/°C above that temperature. This rating assumes use of the minimum recommended footprint and accounts for thermal resistance of 340°C/W (junction-to-ambient) and 150°C/W (junction-to-lead), as specified in the Maximum Ratings table of the ON Semiconductor datasheet.
Does the MMSZ5256BT1 meet automotive qualification standards?
Yes, the MMSZ5256BT1 is AEC−Q101 qualified and PPAP capable, as explicitly stated in the Features section of the ON Semiconductor datasheet. The "SZ" prefix variants (e.g., SZMMSZ5256BT1G) are designated for automotive applications requiring unique site and process controls, but the standard MMSZ5256BT1 shares the same qualification and reliability testing profile per AEC−Q101.
What is the Zener impedance of the MMSZ5256BT1 and why does it matter?
The MMSZ5256BT1 has a maximum Zener impedance (ZZT) of 49 Ω measured at IZT = 4.2 mA and 1 kHz AC frequency. This low dynamic impedance ensures minimal voltage variation under changing load current-critical for maintaining regulation accuracy in feedback loops, reference supplies, and overvoltage protection circuits where stable 30 V clamping is required.
How is polarity marked on the MMSZ5256BT1 SOD−123 package?
The MMSZ5256BT1 uses a cathode band to indicate polarity: Pin 1 (cathode) is marked with a visible band on the SOD−123 case, while Pin 2 (anode) is unmarked. This marking aligns with the mechanical drawing in the Package Dimensions section (page 7) and is essential for correct reverse-bias orientation during PCB layout and assembly-reversal would result in forward conduction instead of Zener regulation.
MMSZ5256BT1 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
MMSZ5256BT1 FAQ
1.How can I place an order for MMSZ5256BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5256BT1 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 MMSZ5256BT1 reliable?
The price and inventory of MMSZ5256BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5256BT1 is usually 5 days.
3.What payment methods are accepted for MMSZ5256BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5256BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5256BT1?
MMSZ5256BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5256BT1 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 MMSZ5256BT1?
For technical support, including MMSZ5256BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5256BT1 requirements.
6.How does Aetrix verify that MMSZ5256BT1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5256BT1 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 MMSZ5256BT1 meets industry standards.
7.What is the process for return or replacement of MMSZ5256BT1?
All MMSZ5256BT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5256BT1, 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 MMSZ5256BT1 part is unused and in its original packaging.
Return procedure for MMSZ5256BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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