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Diodes Incorporated MMBZ5255BW-7
- Part No.:
- MMBZ5255BW-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- -
- Datasheet:
-
MMBZ5255BW-7.pdf
- Description:
- DIODE ZENER 28V 200MW SOT323
- Quantity:
- Payment:
- Shipping:
Inventory:6,214
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Product details
Overview
MMBZ5255BW-7 from Diodes Incorporated is a 28 V, 200 mW surface-mount Zener diode in SOT323 package, rated for 4.5 mA test current with 44 Ω dynamic impedance at 1 kHz and maximum 0.1 μA reverse leakage at 21 V, used for precision voltage regulation and overvoltage protection in low-power analog sensor interfaces.
For engineers reviewing the MMBZ5255BW-7 datasheet, MMBZ5255BW-7 pinout, MMBZ5255BW-7 application, or MMBZ5255BW-7 equivalent, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (625 °C/W), AEC-Q101 qualification, lead-free/Green compliance, and SOT323 footprint compatibility with automated assembly.
Technical Context
This Zener diode operates in reverse breakdown mode to maintain stable reference voltage under varying load and temperature conditions. It features a tightly controlled 26.6–29.4 V Zener voltage range at 4.5 mA, with low dynamic impedance (44 Ω) ensuring minimal output variation across current changes.
Designed for high-reliability applications, it meets AEC-Q101 stress testing requirements and uses halogen/antimony-free molding compound (UL 94V-0). Its 0.006 g mass and moisture sensitivity level 1 rating support robust reflow soldering on FR4 PCBs with recommended pad layout AP02001.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (Nominal) | 28 V - Stable reference point for voltage clamping or biasing circuits |
| Zener Voltage Range | 26.6–29.4 V @ 4.5 mA - ±5% tolerance ensures predictable regulation across production lots |
| Power Dissipation | 200 mW - Limits continuous operating current to ~7.1 mA at 28 V in ambient air |
| Zener Impedance | 44 Ω @ 1 kHz - Low AC impedance preserves regulation accuracy under dynamic load transients |
| Reverse Leakage | 0.1 μA @ 21 V - Negligible standby current in undervoltage detection or standby power rails |
| Thermal Resistance | 625 °C/W - Requires derating above +25°C ambient; full power only at ≤+25°C |
| Package | SOT323 - 2.1 mm × 1.3 mm footprint compatible with high-density PCB layouts |
Pinout & Package
Package: SOT323 - three-terminal surface-mount plastic package with matte tin-plated Alloy 42 leadframe, polarity indicated by cathode band marking per top-view schematic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node; reverse-biased operation requires cathode at higher potential |
| Cathode | Zener breakdown terminal / voltage reference output | Provides regulated 28 V output when reverse biased; marked with band on package top view |
| Case / Heat Sink | Non-electrical mechanical termination | No internal connection; serves only as mechanical anchor and thermal path via PCB copper |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics use including engine control and body modules |
| Lead-free & Green compliant | Meets RoHS 2 (2011/65/EU) with <900 ppm Br, <900 ppm Cl, <1000 ppm Sb |
| Moisture Sensitivity Level 1 | Unlimited floor life at ≤30°C/60% RH - no baking required before reflow |
| Automated assembly optimized | SOT323 geometry supports high-yield pick-and-place and reflow soldering |
Applications
| Industrial Sensor Signal Conditioning | Automotive Cabin Control Module |
|---|---|
Use Scenario: Stabilizing reference voltage for 12-bit ADC inputs in temperature/humidity transmitters. IC Role / Device Role / Timing Role: Zener voltage reference providing 28 V rail for op-amp biasing and analog front-end protection. Use Value: Tight ±5% VZ tolerance and low 44 Ω impedance minimize ADC offset drift across -40°C to +125°C. | Use Scenario: Overvoltage clamp on LIN bus interface power rail exposed to load-dump transients. IC Role / Device Role / Timing Role: Transient voltage suppressor limiting rail voltage to 28 V during 40 V/50 ms pulses. Use Value: AEC-Q101 qualification and 200 mW rating enable reliable clamping without thermal runaway. |
| Medical Wearable Battery Monitor | Smart Home Smoke Detector MCU Supply |
Use Scenario: Precision voltage reference for coulomb counter IC measuring Li-ion battery state-of-charge. IC Role / Device Role / Timing Role: Low-leakage (0.1 μA @ 21 V) Zener establishing accurate threshold for battery undervoltage warning. Use Value: Sub-microamp reverse current prevents measurable battery drain over multi-year device lifetime. | Use Scenario: Regulated 28 V supply for microcontroller reset supervisor and RF transceiver biasing. IC Role / Device Role / Timing Role: Primary voltage regulator in low-quiescent-current power tree feeding ultra-low-power SoC. Use Value: SOT323 footprint enables compact 2-layer PCB design while maintaining 200 mW thermal margin. |
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, 300 mW rating, SOT23 package | Higher power rating but 1 V lower Zener voltage; larger SOT23 footprint | Select when 27 V reference is acceptable and board space allows SOT23 |
| MMSZ5255T1G | 28 V nominal, ±5%, 500 mW, SOD-123 package | Same VZ but double power rating and different package; not AEC-Q101 qualified | Select for non-automotive applications requiring higher surge tolerance |
Compared with BZX84-C27LT1G and MMSZ5255T1G, MMBZ5255BW-7 uniquely combines AEC-Q101 qualification, SOT323 miniaturization, and precise 28 V regulation-making it optimal for space-constrained automotive and industrial modules where reliability and footprint are co-prioritized.
Availability
MMBZ5255BW-7 is available at Aetrix Electronics and suitable for industrial sensor signal conditioning, automotive cabin control modules, and medical wearable battery monitors requiring stable component supply with consistent parametric performance across production batches.
Supply support for MMBZ5255BW-7 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' high-reliability Zener diode product line, engineered specifically for precision voltage reference and transient suppression in automotive, industrial, and medical applications where AEC-Q101 compliance and Green material content are mandatory.
FAQ
What is the maximum reverse voltage this diode can withstand before breakdown?
The MMBZ5255BW-7 has a nominal Zener voltage of 28 V with a guaranteed range of 26.6–29.4 V at 4.5 mA test current. Below 21 V, reverse leakage remains ≤0.1 μA; breakdown is sharply defined within this range and not characterized beyond 29.4 V in the datasheet.
Is this part suitable for use in automotive under-hood environments?
Yes-MMBZ5255BW-7 is qualified to AEC-Q101 standards and rated for operation from –65°C to +150°C. Its halogen-free molding compound and matte tin plating ensure long-term reliability in high-temperature, high-vibration under-hood applications such as engine control unit voltage supervision.
How does the SOT323 package affect thermal performance compared to larger packages?
With a thermal resistance of 625 °C/W (junction-to-ambient on FR4), the SOT323 limits continuous power dissipation to 200 mW only at +25°C ambient. Derating is required above that temperature-e.g., ~125 mW at +75°C-due to its small copper contact area and low mass (0.006 g).
Can this Zener diode be used in place of a TVS diode for ESD protection?
No-MMBZ5255BW-7 is not rated for ESD or surge events. Its 200 mW power rating and lack of specified peak pulse power (unlike dedicated TVS devices) make it unsuitable for IEC 61000-4-2 ESD or ISO 10605 protection; it is intended for steady-state voltage regulation and low-energy clamping only.
MMBZ5255BW-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- -
- Tolerance:
- -
- Power - Max:
- -
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MMBZ5255BW-7 FAQ
1.How can I place an order for MMBZ5255BW-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5255BW-7 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 reliable?
The price and inventory of MMBZ5255BW-7 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 is usually 5 days.
3.What payment methods are accepted for MMBZ5255BW-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5255BW-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5255BW-7?
MMBZ5255BW-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5255BW-7 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?
For technical support, including MMBZ5255BW-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5255BW-7 requirements.
6.How does Aetrix verify that MMBZ5255BW-7 is sourced from the original manufacturer or authorized distributors?
All MMBZ5255BW-7 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 meets industry standards.
7.What is the process for return or replacement of MMBZ5255BW-7?
All MMBZ5255BW-7 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5255BW-7, 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 part is unused and in its original packaging.
Return procedure for MMBZ5255BW-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5255BW-7 Tags
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