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onsemi MMSZ5255BT1
- Part No.:
- MMSZ5255BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5255BT1.pdf
- Description:
- DIODE ZENER 28V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:2,448
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Product details
Overview
MMSZ5255BT1 from ON Semiconductor is a 28 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation on FR−5 board at 75°C, with 4.5 mA test current (IZT), 44 Ω dynamic impedance (ZZT), and 0.1 µA reverse leakage at 21 V (VR). It serves as a precision voltage reference or overvoltage clamp in low-power analog sensing and power supply feedback circuits.
For engineers reviewing the MMSZ5255BT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, SOD−123 mechanical dimensions, cathode/anode polarity marking, and AEC−Q101-qualified alternatives for automotive and industrial designs.
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 ambient variations.
The 5% tolerance variant uses a "B" suffix and exhibits 0.25 V forward voltage max at 10 mA forward current. Its 21 V reverse voltage rating (VR) and 0.1 µA leakage at that bias enable reliable clamping in 24 V system rails without excessive standby current draw.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 26.6–29.4 V @ IZT = 4.5 mA - defines regulated output voltage window for feedback or reference use |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - sets maximum continuous power handling on standard PCBs |
| Zener Impedance (ZZT) | 600 Ω @ IZK = 0.25 mA - indicates regulation stiffness at low-current knee region |
| Reverse Leakage (IR) | 0.1 µA @ VR = 21 V - ensures minimal quiescent current in high-impedance clamp applications |
| Forward Voltage (VF) | 0.95 V max @ IF = 10 mA - confirms low-loss conduction in forward-biased protection paths |
| Junction Temp Range | −55°C to +150°C - supports operation in under-hood automotive and industrial environments |
| ESD Rating | Class 3 (>16 kV HBM) - provides robustness against handling and system-level electrostatic discharge |
Pinout & Package
SOD−123 surface-mount plastic package (Case 425, Style 1), void-free thermosetting body with corrosion-resistant finish; cathode indicated by polarity band; 260°C max soldering temperature for 10 seconds; UL 94 V−0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener breakdown terminal | Connected to regulated node; voltage referenced to anode; polarity band identifies this terminal |
| 2 (Anode) | Reference/ground terminal | Typically tied to circuit ground or lower-potential rail; completes Zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW FR−5 board rating | Enables direct integration into cost-sensitive consumer and industrial PCBs without heatsinking |
| ±5% Zener tolerance | Provides predictable voltage setpoint for non-critical regulation where tight accuracy isn't required |
| AEC−Q101 qualified | Validates reliability for automotive body electronics, infotainment power supplies, and sensor interfaces |
| Pb−Free construction | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements |
| Small SOD−123 footprint | Supports high-density layouts in space-constrained modules like IoT edge nodes and portable equipment |
Applications
| Automotive Body Control Module | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Clamping transient spikes on 24 V CAN bus power lines during load dump events. IC Role / Device Role / Timing Role: Zener diode acting as shunt overvoltage protector in parallel with downstream regulators. Use Value: Limits voltage to ≤29.4 V during surges, preventing damage to 3.3 V/5 V logic supplies powered from the same rail. | Use Scenario: Providing stable 28 V reference for ratiometric bridge sensor excitation in pressure transducers. IC Role / Device Role / Timing Role: Precision voltage reference source for analog front-end excitation circuitry. Use Value: Delivers <±0.3 V variation over −40°C to +125°C, enabling sub-0.5% full-scale measurement accuracy. |
| Consumer Power Adapter Feedback | Medical Diagnostic Equipment Bias Supply |
Use Scenario: Secondary-side voltage sensing in isolated flyback converters for USB-C PD adapters. IC Role / Device Role / Timing Role: Zener-based optocoupler feedback reference for TL431 replacement in cost-optimized designs. Use Value: Maintains ±5% regulation across line/load transients, meeting IEC 62368-1 safety margin requirements. | Use Scenario: Generating clean bias voltage for low-noise op-amps in ECG front-end amplifiers. IC Role / Device Role / Timing Role: Low-leakage voltage clamp to protect amplifier inputs from ESD and overvoltage faults. Use Value: 0.1 µA leakage at 21 V prevents input offset drift in picoampere-level signal paths. |
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-C27 | 27 V ±5%, SOT−23 package, 300 mW rating, 80 Ω ZZT @ 5 mA | Higher dynamic impedance and lower power rating limit use in high-stability references | Select when board space permits SOT−23 and thermal budget allows reduced derating |
| SZMMSZ5255BT1G | Identical electrical specs; AEC−Q101 qualified with SZ prefix; Pb−Free | Designed specifically for automotive PPAP-compliant production with enhanced traceability | Choose for Tier-1 automotive programs requiring certified change control and lot traceability |
Compared with MMSZ5255BT1, BZX84-C27 offers smaller footprint but sacrifices 40% power handling and regulation stiffness; SZMMSZ5255BT1G matches all electrical parameters while adding automotive qualification and Pb−Free compliance-ideal for production ramp in vehicle ECUs.
Availability
MMSZ5255BT1 is available at Aetrix Electronics and suitable for automotive body control, industrial sensor conditioning, consumer power adapter feedback, and medical diagnostic equipment bias supply requiring stable component supply across long product lifecycles.
Supply support for MMSZ5255BT1 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The MMSZ52xxxT1G series targets general-purpose medium-current Zener regulation in compact SOD−123 packages, designed for cost-sensitive, high-volume applications needing AEC−Q101 qualification and RoHS compliance.
FAQ
What is the nominal Zener voltage of MMSZ5255BT1 and how is it measured?
The nominal Zener voltage of MMSZ5255BT1 is 28 V, with a minimum of 26.6 V and maximum of 29.4 V at IZT = 4.5 mA. It is measured under thermal equilibrium conditions at lead temperature TL = 30°C ±1°C, ensuring stable voltage reference performance independent of short-term self-heating effects during testing. This specification applies directly to MMSZ5255BT1 and is confirmed in the ON Semiconductor datasheet revision 15.
Does MMSZ5255BT1 meet automotive qualification standards?
Yes, MMSZ5255BT1 is part of the AEC−Q101-qualified MMSZ52xxxT1G series. While the base MMSZ5255BT1 carries the standard "B" suffix, its automotive-grade counterpart SZMMSZ5255BT1G shares identical electrical characteristics and adds PPAP capability, site-specific control, and enhanced traceability required for automotive production. Both variants comply with the same stress test requirements defined in AEC−Q101.
What is the maximum allowable reverse voltage (VR) for MMSZ5255BT1 and why does it matter?
The maximum reverse voltage VR for MMSZ5255BT1 is 21 V, at which leakage current is guaranteed ≤0.1 µA. This parameter defines the safe operating threshold below the Zener breakdown region-critical for use as a clamp in 24 V systems where transient suppression must activate only above nominal rail voltage. Exceeding VR risks premature conduction and increased power loss, so MMSZ5255BT1 is best applied where clamping action is needed above 21 V but within its 26.6–29.4 V regulation band.
How does the SOD−123 package of MMSZ5255BT1 affect thermal performance?
The SOD−123 package of MMSZ5255BT1 delivers a thermal resistance of 340°C/W (junction-to-ambient) on FR−5 board, limiting continuous power dissipation to 500 mW at 75°C lead temperature. Derating is linear at 6.7 mW/°C above 75°C, meaning usable power drops to ~330 mW at 125°C ambient. This thermal profile makes MMSZ5255BT1 suitable for low-duty-cycle clamping or reference use but not sustained high-current regulation without board-level copper thermal relief.
Can MMSZ5255BT1 be used as a direct replacement for older MMSZ5255BT1G parts?
Yes, MMSZ5255BT1 is functionally and mechanically identical to MMSZ5255BT1G, differing only in tape-and-reel packaging configuration (T1 vs T1G suffix denotes Pb−Free compliance and moisture sensitivity level). Electrical specifications-including Zener voltage, impedance, leakage, and thermal ratings-are fully aligned per ON Semiconductor documentation. No PCB layout or schematic changes are required when substituting MMSZ5255BT1 for MMSZ5255BT1G in existing designs.
MMSZ5255BT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 28 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 44 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 21 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
MMSZ5255BT1 FAQ
1.How can I place an order for MMSZ5255BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5255BT1 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 MMSZ5255BT1 reliable?
The price and inventory of MMSZ5255BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5255BT1 is usually 5 days.
3.What payment methods are accepted for MMSZ5255BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5255BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5255BT1?
MMSZ5255BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5255BT1 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 MMSZ5255BT1?
For technical support, including MMSZ5255BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5255BT1 requirements.
6.How does Aetrix verify that MMSZ5255BT1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5255BT1 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 MMSZ5255BT1 meets industry standards.
7.What is the process for return or replacement of MMSZ5255BT1?
All MMSZ5255BT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5255BT1, 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 MMSZ5255BT1 part is unused and in its original packaging.
Return procedure for MMSZ5255BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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