My Inquiry
My Account
Diodes Incorporated MMBZ5255B-7-F
- Part No.:
- MMBZ5255B-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5255B-7-F.pdf
- Description:
- DIODE ZENER 28V 350MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,763
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MMBZ5255B-7-F from Diodes Incorporated is a 28 V, 4.5 mA nominal Zener diode in SOT23 package, rated for 350 mW power dissipation on FR-4 PCB, with 44 Ω dynamic impedance at 1 kHz and 0.1 µA reverse leakage at 21 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMBZ5255B-7-F datasheet, MMBZ5255B-7-F pinout, MMBZ5255B-7-F application, or MMBZ5255B-7-F equivalent, this page delivers verified Zener voltage tolerance (±3.57%), thermal resistance (357 °C/W), JEDEC-compliant reliability, and SOT23 terminal mapping for layout and BOM validation.
Technical Context
This Zener diode operates in reverse breakdown mode with tightly controlled 28 V nominal regulation across 26.6–29.4 V (±3.57%) at 4.5 mA test current. Its 44 Ω Zener impedance at 1 kHz ensures stable regulation under small-signal AC ripple conditions.
Designed for surface-mount automated assembly, it features matte tin-plated Alloy 42 leads, moisture sensitivity level 1 per J-STD-020, and UL 94V-0 molded plastic packaging - all supporting high-reliability industrial and automotive-qualified derivative variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28 V nominal, 26.6–29.4 V range at IZT = 4.5 mA - defines precise clamping threshold for reference and protection circuits |
| Power Dissipation (PD) | 350 mW on FR-4 PCB - sets maximum continuous DC/average power handling without derating below 25°C ambient |
| Zener Impedance (ZZT) | 44 Ω at f = 1 kHz - determines AC voltage deviation under varying load current, critical for low-noise references |
| Reverse Leakage (IR) | 0.1 µA at VR = 21 V - ensures minimal standby current in high-impedance bias networks and sensing paths |
| Thermal Resistance (RθJA) | 357 °C/W - quantifies junction-to-ambient temperature rise per watt, essential for thermal margin calculation on standard PCBs |
| Operating Temperature | −65 to +150 °C - supports extended-range operation in industrial control, automotive under-hood, and outdoor electronics |
Pinout & Package
Package: SOT23 - 3-terminal surface-mount plastic package with 0.915 mm lead pitch, 2.40 mm body length, and 1.30 mm body width; optimized for reflow soldering and automated pick-and-place.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Forward conduction terminal / cathode reference ground path | Connected to system ground or lower-potential node when used in shunt regulation configuration |
| Cathode (Pin 2) | Zener breakdown terminal / regulated output node | Provides stable 28 V reference when reverse-biased; connects to input supply via series resistor |
| No-Connect (Pin 3) | Non-functional mechanical support terminal | Internally unconnected; serves as structural anchor in SOT23 mold compound - must remain floating in layout |
Key Features
| Feature | Design Value |
|---|---|
| Planar die construction | Enables tight VZ tolerance (±3.57%) and repeatable Zener impedance across production lots |
| 350 mW FR-4 power rating | Validated thermal performance on standard PCBs without heatsinking - simplifies low-power design |
| Lead-free & RoHS 3 compliant | Fully compliant with EU Directive 2015/863/EU - supports global environmental compliance without process change |
| Moisture Sensitivity Level 1 | Zero bake requirement before reflow - reduces manufacturing cost and avoids thermal stress on components |
| UL 94V-0 flammability rating | Self-extinguishing encapsulant meets safety standards for consumer, industrial, and automotive end equipment |
Applications
| Industrial Sensor Signal Conditioning | USB-C Power Delivery Clamp |
|---|---|
|
Use Scenario: Stabilizing reference voltage for 24-bit ADC front-end in pressure transducers operating from 24 V DC rails. IC Role / Device Role / Timing Role: Shunt Zener regulator providing 28 V reference to op-amp bias network and ADC reference buffer. Use Value: 44 Ω ZZT minimizes code-dependent reference drift; 0.1 µA IR prevents loading of high-Z sensor bridges. |
Use Scenario: Overvoltage clamp on VBUS line during USB-C PD negotiation to protect 3.3 V logic interface ICs. IC Role / Device Role / Timing Role: Fast-acting transient suppressor limiting VBUS to ≤29.4 V during fault events. Use Value: 26.6–29.4 V regulation window ensures clamping occurs before damage threshold of downstream 30 V-rated transceivers. |
| Automotive Body Control Module (BCM) Reset Circuit | Programmable Logic Controller (PLC) Input Protection |
|
Use Scenario: Generating clean reset signal for microcontroller in BCM exposed to 12 V battery transients up to ±100 V. IC Role / Device Role / Timing Role: Zener-based voltage supervisor feeding RC delay into MCU reset pin. Use Value: −65 to +150 °C operating range matches under-dash thermal profile; 350 mW rating handles ISO 7637-2 pulse 5a energy. |
Use Scenario: Protecting 24 V digital input channel of modular PLC against field-wiring induced surges and polarity reversal. IC Role / Device Role / Timing Role: Bidirectional clamp (with series diode) limiting input voltage to safe levels for optocoupler LED driver. Use Value: SOT23 footprint enables compact input-stage protection; 0.008 g weight supports vibration-resistant mounting in industrial 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 (25.65–28.35 V), 500 Ω ZZK at 1 mA - higher impedance, looser tolerance | Acceptable where 27 V clamping suffices and tighter regulation is not required | Select for cost-sensitive designs where ±5% VZ and higher dynamic impedance are acceptable |
| MMBZ5254B-7-F | 27 V nominal, 25.65–28.35 V range, 41 Ω ZZT at 5.0 mA - 1 V lower VZ, slightly lower ZZT | Direct drop-in for 27 V systems; requires recalculation of series resistor for same current | Choose when migrating legacy 27 V designs or when tighter 27 V regulation is preferred over 28 V |
Compared with BZX84-C27LT1G, MMBZ5255B-7-F offers 3.57% VZ tolerance and 44 Ω ZZT versus ±5% and 500 Ω - enabling higher-precision references; versus MMBZ5254B-7-F, it provides 1 V higher clamping with identical package and thermal behavior.
Availability
MMBZ5255B-7-F is available at Aetrix Electronics and suitable for industrial sensor conditioning, USB-C power delivery protection, and automotive body control modules requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for MMBZ5255B-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.
This device belongs to the MMBZ52xxB Zener diode family, engineered for high-volume, high-reliability surface-mount voltage regulation in space-constrained industrial and automotive applications.
FAQ
What is the exact Zener voltage tolerance for MMBZ5255B-7-F?
The MMBZ5255B-7-F has a nominal Zener voltage of 28 V with a guaranteed range of 26.6 V to 29.4 V at 4.5 mA test current, corresponding to ±3.57% tolerance. This specification is measured per JEDEC-standard short-pulse testing to minimize self-heating effects.
Can MMBZ5255B-7-F be used in automotive applications?
Yes - while the standard MMBZ5255B-7-F is not AEC-Q200 qualified, Diodes Incorporated offers automotive-grade variants (e.g., MMBZ5255BQ-7-F) with PPAP capability, manufactured in IATF 16949-certified facilities and qualified to AEC-Q200. These carry Q-suffix part numbers and meet automotive change control requirements.
What is the thermal resistance of MMBZ5255B-7-F on a standard PCB?
The junction-to-ambient thermal resistance (RθJA) is 357 °C/W when mounted on an FR-4 printed circuit board using Diodes' recommended pad layout. This value assumes no additional copper pour or thermal vias - adding thermal relief improves heat dissipation.
How does the SOT23 pinout map to Zener functionality?
In the SOT23 package, Pin 1 is the anode, Pin 2 is the cathode, and Pin 3 is internally unconnected. For shunt regulation, the cathode connects to the voltage rail being regulated, and the anode connects to ground through a current-limiting resistor - consistent with standard Zener diode biasing convention.
MMBZ5255B-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 28 V
- Tolerance:
- ±5%
- Power - Max:
- 350 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-23-3
MMBZ5255B-7-F FAQ
1.How can I place an order for MMBZ5255B-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5255B-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 MMBZ5255B-7-F reliable?
The price and inventory of MMBZ5255B-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 MMBZ5255B-7-F is usually 5 days.
3.What payment methods are accepted for MMBZ5255B-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5255B-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5255B-7-F?
MMBZ5255B-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5255B-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 MMBZ5255B-7-F?
For technical support, including MMBZ5255B-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5255B-7-F requirements.
6.How does Aetrix verify that MMBZ5255B-7-F is sourced from the original manufacturer or authorized distributors?
All MMBZ5255B-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 MMBZ5255B-7-F meets industry standards.
7.What is the process for return or replacement of MMBZ5255B-7-F?
All MMBZ5255B-7-F units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5255B-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 MMBZ5255B-7-F part is unused and in its original packaging.
Return procedure for MMBZ5255B-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5255B-7-F Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
