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Diodes Incorporated MMBZ5255BW-7-F
- Part No.:
- MMBZ5255BW-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- SC-70, SOT-323
- Datasheet:
-
MMBZ5255BW-7-F.pdf
- Description:
- DIODE ZENER 28V 200MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:4,874
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Product details
Overview
MMBZ5255BW-7-F from Diodes Incorporated is a 28 V, 4.5 mA nominal zener diode in SOT323 package, rated for 200 mW power dissipation and 44 Ω zener impedance at test current, designed for precision voltage regulation and overvoltage protection in low-power analog and digital circuits.
For engineers reviewing the MMBZ5255BW-7-F datasheet, MMBZ5255BW-7-F pinout, MMBZ5255BW-7-F application, or MMBZ5255BW-7-F equivalent, key selection criteria include zener voltage tolerance (±3.6%), reverse leakage (<0.1 μA at 21 V), thermal resistance (625 °C/W), and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
This device operates as a silicon planar zener diode with sharp reverse breakdown characteristics, optimized for stable reference voltage generation under low-current conditions (IZT = 4.5 mA). Its 28 V nominal zener voltage is maintained within ±3.6% tolerance across manufacturing lots and temperature ranges.
The SOT323 package enables high-density PCB layouts while supporting automated reflow assembly. With 625 °C/W junction-to-ambient thermal resistance and 200 mW maximum power rating, it delivers predictable regulation in ambient temperatures from –65 °C to +150 °C without forced cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28 V nominal, 26.6–29.4 V range at 4.5 mA - ensures stable reference in 24 V system rails |
| Power Dissipation (PD) | 200 mW - limits thermal rise in compact SOT323 footprint without heatsinking |
| Zener Impedance (ZZT) | 44 Ω at 4.5 mA - maintains voltage stability under small-signal load variations |
| Reverse Leakage (IR) | <0.1 μA at 21 V - minimizes quiescent current in battery-powered sensing nodes |
| Thermal Resistance (RθJA) | 625 °C/W - defines temperature rise per milliwatt on standard FR4 board |
| Operating Temperature | –65 °C to +150 °C - supports under-hood automotive and industrial control environments |
Pinout & Package
Package: SOT323 - surface-mount plastic case with matte tin-plated Alloy 42 leadframe, moisture sensitivity level 1, UL 94V-0 rated, weight ≈ 0.006 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal | Connected to lower-potential node during regulation; polarity marked by cathode band on top view |
| Cathode (Pin 2) | Zener breakdown terminal | Connected to higher-potential node; voltage referenced to this pin during reverse bias operation |
| Case / Pin 3 | No internal connection | Non-functional thermal pad; electrically isolated, no circuit role |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including HTOL, TC, HAST |
| Green compound packaging | Halogen- and antimony-free molding compound (<900 ppm Br/Cl, <1000 ppm Sb) |
| SOT323 footprint | Compatible with high-speed pick-and-place and reflow processes; 2.1 mm × 1.3 mm body size |
| Low leakage performance | ≤0.1 μA at 75% of VZ - preserves battery life in always-on monitoring circuits |
Applications
| Automotive Sensor Reference | Industrial I/O Protection |
|---|---|
Use Scenario: Providing stable 28 V reference for pressure sensor signal conditioning in engine control units. IC Role / Device Role / Timing Role: Zener diode acting as shunt voltage reference for op-amp biasing and ADC input scaling. Use Value: Tight 26.6–29.4 V tolerance ensures consistent sensor output scaling across temperature and supply variance. | Use Scenario: Clamping transient surges on 24 V fieldbus lines in PLC analog input modules. IC Role / Device Role / Timing Role: Reverse-biased zener used as overvoltage clamp to protect downstream op-amps and ADCs. Use Value: 44 Ω dynamic impedance limits clamping voltage overshoot during fast transients (e.g., ISO 7637-2 Pulse 1). |
| Portable Medical Monitor Supply | Smart Meter Voltage Regulation |
Use Scenario: Regulating auxiliary 28 V rail for ECG front-end amplifiers in battery-powered patient monitors. IC Role / Device Role / Timing Role: Low-power shunt regulator maintaining clean bias voltage for precision instrumentation amps. Use Value: Sub-0.1 μA leakage at 21 V extends battery runtime in multi-day continuous monitoring modes. | Use Scenario: Stabilizing microcontroller VREF supply in electricity meters operating from 24 V DC backup rails. IC Role / Device Role / Timing Role: Precision voltage reference source for 16-bit sigma-delta ADC reference buffer. Use Value: 625 °C/W RθJA allows operation up to +85 °C ambient without derating in sealed meter enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C27LT1G | 27 V nominal, ±5% tolerance, 30 Ω ZZT at 5 mA | Lower voltage grade; tighter impedance but wider VZ tolerance | Select when 27 V reference suffices and lower dynamic impedance is prioritized over voltage accuracy |
| MMSZ5255T1G | 28 V nominal, ±5% tolerance, 45 Ω ZZT at 4.5 mA, SOD-123 package | Larger footprint (3.5 mm × 1.6 mm), higher RθJA (500 °C/W) | Choose for manual prototyping or where SOD-123 handling is preferred over SOT323 automation |
Compared with BZX84-C27LT1G and MMSZ5255T1G, MMBZ5255BW-7-F offers superior voltage accuracy (±3.6% vs. ±5%) and AEC-Q101 qualification, making it preferred for automotive and high-reliability industrial designs where tight regulation and stress validation are mandatory.
Availability
MMBZ5255BW-7-F is available at Aetrix Electronics and suitable for automotive sensor reference, industrial I/O protection, and portable medical monitor supply requiring stable component supply and long-term lifecycle support.
Supply support for MMBZ5255BW-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, manufacturing, and sales operations across Asia, Europe, and North America.
The MMBZ52xxBW series belongs to Diodes' AEC-Q101-qualified zener diode product line, engineered specifically for voltage reference and transient suppression in automotive and industrial control systems where reliability and consistency are critical.
FAQ
What is the maximum reverse voltage (VR) before significant leakage occurs?
At 21 V (75% of nominal 28 V), reverse leakage is guaranteed ≤0.1 μA per datasheet Table on page 2. Beyond 21 V, leakage rises nonlinearly; operation above 29.4 V risks irreversible breakdown unless current-limited to <4.5 mA.
Is MMBZ5255BW-7-F suitable for use in a 24 V automotive system?
Yes - its 28 V zener voltage provides headroom above 24 V nominal rails, and AEC-Q101 qualification confirms suitability for automotive environments including temperature cycling, humidity, and vibration stress per JESD22 standards.
How does the SOT323 package affect thermal performance compared to larger packages?
SOT323's 625 °C/W RθJA reflects its small thermal mass and limited copper pad area. On standard FR4 with recommended AP02001 pad layout, it dissipates 200 mW only up to +75 °C ambient; derating is required above that per Figure 1.
Can this zener diode replace a 27 V part in an existing design?
Only if the circuit tolerates +3.7% higher reference voltage and reduced margin between operating rail and breakdown. At 24 V supply, 28 V zener yields 4 V headroom vs. 3 V for 27 V - verify clamping energy and thermal rise remain within spec before substitution.
MMBZ5255BW-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 28 V
- Tolerance:
- ±5%
- Power - Max:
- 200 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
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
MMBZ5255BW-7-F FAQ
1.How can I place an order for MMBZ5255BW-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5255BW-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 MMBZ5255BW-7-F reliable?
The price and inventory of MMBZ5255BW-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 MMBZ5255BW-7-F is usually 5 days.
3.What payment methods are accepted for MMBZ5255BW-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5255BW-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5255BW-7-F?
MMBZ5255BW-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5255BW-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 MMBZ5255BW-7-F?
For technical support, including MMBZ5255BW-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5255BW-7-F requirements.
6.How does Aetrix verify that MMBZ5255BW-7-F is sourced from the original manufacturer or authorized distributors?
All MMBZ5255BW-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 MMBZ5255BW-7-F meets industry standards.
7.What is the process for return or replacement of MMBZ5255BW-7-F?
All MMBZ5255BW-7-F units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5255BW-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 MMBZ5255BW-7-F part is unused and in its original packaging.
Return procedure for MMBZ5255BW-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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