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Diodes Incorporated MMSZ5255BQ-7-F
- Part No.:
- MMSZ5255BQ-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5255BQ-7-F.pdf
- Description:
- DIODE ZENER 28V 370MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:1,840
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Product details
Overview
MMSZ5255BQ-7-F from Diodes Incorporated is an automotive-grade 28 V, ±3.5% tolerance Zener diode in SOD123 package, rated for 500 mW power dissipation at TL = +75°C and 370 mW at TA = +25°C, with 44 Ω zener impedance at 4.5 mA test current and 0.1 µA reverse leakage at 21 V. It serves as a precision voltage reference or overvoltage clamp in low-power analog monitoring circuits.
For engineers reviewing the MMSZ5255BQ-7-F datasheet, MMSZ5255BQ-7-F pinout, MMSZ5255BQ-7-F application, or MMSZ5255BQ-7-F equivalent, key selection criteria include its AEC-Q101 qualification, tight 26.6–29.4 V zener voltage range, low 0.1 µA IR at VR = 21 V, thermal resistance of 338 °C/W on FR-4, and SOD123 footprint compatibility with automated assembly.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable voltage regulation across varying load and temperature conditions. Its 28 V nominal zener voltage exhibits a positive temperature coefficient (~+0.07%/°C), and it delivers 44 Ω dynamic impedance at IZT = 4.5 mA - optimized for medium-current reference stability.
The device uses a matte tin–plated alloy 42 leadframe, cathode-band polarity marking, and green molding compound compliant with halogen/antimony-free requirements. It is qualified per AEC-Q101 for automotive underhood applications where reliability across –65°C to +150°C is mandatory.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 28 V (26.6–29.4 V range at 4.5 mA; enables precise 28 V rail clamping) |
| Power Dissipation | 370 mW @ TA = +25°C (limits continuous current to ~13.2 mA at 28 V) |
| Zener Impedance | 44 Ω @ IZT = 4.5 mA (ensures <1.2 V regulation deviation under 1 mA load change) |
| Reverse Leakage | 0.1 µA @ VR = 21 V (minimizes standby current in battery-powered voltage monitors) |
| Thermal Resistance | 338 °C/W junction-to-ambient (requires thermal pad design for >100 mW sustained operation) |
| Operating Temperature | –65°C to +150°C (supports engine control unit and ADAS sensor module environments) |
Pinout & Package
Package: SOD123 surface-mount plastic case with cathode band marking; dimensions: 1.55 mm × 2.65 mm × 1.05 mm (L × W × H); weight ≈ 0.01 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to system ground or lower-potential node; forms reference return path |
| Cathode | Zener breakdown terminal / voltage regulation output | Connected to regulated node; maintains 28 V relative to anode during reverse bias |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive underhood use with extended temperature cycling and humidity testing |
| SOD123 package | Compatible with standard 0805 pick-and-place equipment and IPC-7351B land pattern |
| Green molding compound | UL 94V-0 rated, halogen-free (<900 ppm Br+Cl), antimony-free (<1000 ppm Sb) |
| Matte tin lead finish | Solderable per MIL-STD-202, Method 208; supports Pb-free reflow profiles up to 260°C |
Applications
| Automotive Sensor Reference | Industrial Power Monitor |
|---|---|
Use Scenario: Providing stable 28 V reference for analog front-end of exhaust gas temperature sensor in Tier-1 ECU modules. IC Role / Device Role / Timing Role: Zener voltage reference for ADC input scaling and fault-detection threshold generation. Use Value: Maintains ±0.5% reference accuracy over –40°C to +125°C due to matched TC and low IR drift. |
Use Scenario: Clamping auxiliary 24 V supply rail in programmable logic controller (PLC) I/O modules. IC Role / Device Role / Timing Role: Overvoltage protection element limiting transient spikes to ≤29.4 V before TVS activation. Use Value: Absorbs 370 mW continuously without derating below +85°C ambient, reducing need for heatsinking. |
| Medical Battery Management | Telecom DC-DC Feedback |
Use Scenario: Setting charge termination threshold in portable defibrillator battery pack supervisor ICs. IC Role / Device Role / Timing Role: Precision voltage reference for comparator-based cell voltage monitoring. Use Value: 0.1 µA leakage ensures <1 nA error contribution to 1 µA sense current paths. |
Use Scenario: Secondary-side feedback reference in isolated 48 V to 3.3 V flyback converters for base station radios. IC Role / Device Role / Timing Role: Zener shunt regulator defining optocoupler LED current setpoint. Use Value: 44 Ω impedance stabilizes feedback loop gain across line/load transients, improving regulation to ±1.2%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C27LT1G | 27 V nominal, ±5% tolerance, SOT-23 package, 300 mW rating | Lower power handling and looser tolerance; unsuitable for 28 V precision clamping | Select only if board space allows SOT-23 and 27 V ±1.35 V range meets system margin |
| MMBZ5255BS-7-F | Same 28 V rating, SOD-323 package, 200 mW power rating | Smaller footprint but 46% lower power dissipation; requires derating above +65°C | Choose for space-constrained designs where peak power remains <150 mW |
Compared with BZX84-C27LT1G and MMBZ5255BS-7-F, MMSZ5255BQ-7-F uniquely combines AEC-Q101 qualification, 370 mW at +25°C, and 26.6–29.4 V tight tolerance in SOD123 - making it the only option validated for automotive 12 V/24 V system voltage references requiring long-term stability.
Availability
MMSZ5255BQ-7-F is available at Aetrix Electronics and suitable for automotive ECU voltage supervision, industrial PLC power monitoring, and medical battery management systems requiring stable component supply with full traceability and AEC-Q101 compliance.
Supply support for MMSZ5255BQ-7-F 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.
MMSZ5255BQ-7-F belongs to the MMSZ52xxB automotive Zener series, engineered specifically for high-reliability voltage regulation in harsh-environment automotive and industrial applications where AEC-Q101 compliance and tight parametric control are mandatory.
FAQ
What is the maximum steady-state power dissipation for MMSZ5255BQ-7-F at +100°C ambient?
At TA = +100°C, the device must be derated linearly from 370 mW at +25°C using the 338 °C/W RθJA value. The allowable power is 370 mW × (1 − (100 − 25)/338) = 112 mW. This assumes standard FR-4 PCB layout with 1-inch² copper pad; actual capability depends on board thermal design.
Is MMSZ5255BQ-7-F compatible with lead-free reflow soldering processes?
Yes. Its matte tin–plated alloy 42 leadframe is qualified for Pb-free reflow per J-STD-020, supporting peak temperatures up to 260°C. The SOD123 package withstands standard JEDEC moisture sensitivity Level 1 handling without baking prior to assembly.
How does the temperature coefficient affect regulation accuracy over –40°C to +125°C?
Data sheet Figure 6 shows +0.07%/°C TC for 28 V devices. Over 165°C span, total drift is ~11.6 mV/°C × 165°C = ±1.9 V - resulting in a practical regulation band of 26.1 V to 29.9 V. System-level calibration or TC compensation is recommended for sub-1% accuracy.
Can MMSZ5255BQ-7-F replace MMSZ5254BQ-7-F in existing designs?
No. MMSZ5254BQ-7-F is rated for 27 V (25.65–28.35 V), while MMSZ5255BQ-7-F is 28 V (26.6–29.4 V). The 1 V nominal shift alters clamping thresholds and may violate safety margins in overvoltage protection circuits; redesign validation is required.
MMSZ5255BQ-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 28 V
- Tolerance:
- ±5%
- Power - Max:
- 370 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:
- -65°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
MMSZ5255BQ-7-F FAQ
1.How can I place an order for MMSZ5255BQ-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5255BQ-7-F 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 MMSZ5255BQ-7-F reliable?
The price and inventory of MMSZ5255BQ-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5255BQ-7-F is usually 5 days.
3.What payment methods are accepted for MMSZ5255BQ-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5255BQ-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5255BQ-7-F?
MMSZ5255BQ-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5255BQ-7-F 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 MMSZ5255BQ-7-F?
For technical support, including MMSZ5255BQ-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5255BQ-7-F requirements.
6.How does Aetrix verify that MMSZ5255BQ-7-F is sourced from the original manufacturer or authorized distributors?
All MMSZ5255BQ-7-F 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 MMSZ5255BQ-7-F meets industry standards.
7.What is the process for return or replacement of MMSZ5255BQ-7-F?
All MMSZ5255BQ-7-F units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5255BQ-7-F, 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 MMSZ5255BQ-7-F part is unused and in its original packaging.
Return procedure for MMSZ5255BQ-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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