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Diodes Incorporated MMSZ5251B-7
- Part No.:
- MMSZ5251B-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5251B-7.pdf
- Description:
- DIODE ZENER 22V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:7,102
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Product details
Overview
MMSZ5251B-7 from Diodes Incorporated is a 22 V, 500 mW surface-mount Zener diode in SOD123 package, rated for 5.6 mA test current with 29 Ω dynamic impedance at 1 kHz and maximum 0.1 µA reverse leakage at 17 V, widely used for voltage regulation and reference in power supply feedback loops.
For engineers reviewing the MMSZ5251B-7 datasheet, MMSZ5251B-7 pinout, MMSZ5251B-7 application, or MMSZ5251B-7 equivalent, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (338 °C/W), AEC-Q101 qualification, RoHS/Green compliance, and SOD123 footprint compatibility with automated assembly.
Technical Context
This Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and line conditions. Its 22 V nominal Zener voltage exhibits a positive temperature coefficient (~0.07 %/°C) per Figure 6, and it delivers regulated output with ≤29 Ω impedance at 5.6 mA test current.
The device is rated for 370 mW power dissipation at 25 °C ambient and derates linearly to 500 mW at 75 °C lead temperature. It features a cathode band polarity marker, matte tin-plated Alloy 42 leadframe, and moisture sensitivity level 1 per J-STD-020.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 22 V nominal, 20.9–23.1 V range at 5.6 mA - ensures ±5% regulation tolerance in precision reference circuits |
| Power Dissipation (PD) | 370 mW @ TA = 25 °C - defines maximum continuous power in standard PCB layout without forced cooling |
| Zener Impedance (ZZT) | 29 Ω @ 1 kHz, 5.6 mA - determines AC ripple rejection capability in low-noise voltage references |
| Reverse Leakage (IR) | 0.1 µA @ VR = 17 V - guarantees minimal quiescent current draw in battery-powered bias networks |
| Thermal Resistance (RθJA) | 338 °C/W - indicates junction-to-ambient heat transfer efficiency on FR-4 with 1-inch copper pad |
| Operating Temperature | −65 to +150 °C - supports industrial and automotive under-hood applications requiring wide thermal margin |
| AEC-Q101 Qualified | Yes - validated for automotive electronics per stress-test requirements including HTGB, TCT, and HTRB |
Pinout & Package
Package: SOD123 - surface-mount plastic case with cathode band marking; dimensions: 2.65 mm × 1.55 mm × 1.05 mm (L × W × H); weight ≈ 0.01 g; UL 94V-0 rated molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground | Connected to circuit ground or lower-potential node in shunt regulator configuration |
| Cathode | Reverse-biased Zener terminal / voltage reference output | Connected to regulated node; cathode band identifies this terminal for correct PCB orientation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW power rating at TL = 75 °C | Enables higher transient power handling in thermally constrained layouts with local heatsinking |
| AEC-Q101 qualification | Validates reliability for automotive body control modules, infotainment power rails, and ADAS sensor supplies |
| Lead-free, halogen- and antimony-free "Green" construction | Meets global environmental compliance mandates (RoHS 2, JEDEC JS709) without compromising solderability |
| SOD123 package with Level 1 moisture sensitivity | Eliminates bake requirements before reflow, reducing manufacturing cost and process complexity |
Applications
| Switching Power Supply Feedback | Automotive ECU Reference |
|---|---|
Use Scenario: Regulating output voltage in flyback or buck converter secondary-side feedback loop. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 22 V threshold to optocoupler input or TL431 comparator. Use Value: Maintains ±1% output accuracy over temperature and line variation due to tight 20.9–23.1 V tolerance and low 29 Ω impedance. |
Use Scenario: Generating stable bias voltage for microcontroller ADC reference or CAN transceiver VIO. IC Role / Device Role / Timing Role: Precision Zener reference supplying clean 22 V to analog subsystems in engine control units. Use Value: Delivers <0.1 µA leakage at 17 V, minimizing current drain in always-on vehicle networks while meeting AEC-Q101 stress requirements. |
| Industrial Sensor Signal Conditioning | Consumer Device Overvoltage Protection |
Use Scenario: Providing excitation voltage for 4–20 mA transmitter loop-powered sensors. IC Role / Device Role / Timing Role: Stable 22 V rail generator ensuring consistent sensor output scaling independent of supply fluctuations. Use Value: Achieves <±5% regulation across −40 to +125 °C ambient via positive TC compensation and low thermal resistance. |
Use Scenario: Clamping transient surges on USB or HDMI power lines in portable electronics. IC Role / Device Role / Timing Role: Low-capacitance (≈15 pF) shunt protector limiting voltage spikes to safe levels before IC inputs. Use Value: Limits clamping voltage to ≤23.1 V during ESD events while drawing negligible standby current (<0.1 µA). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C22 (Nexperia) | 22 V, ±5%, 300 mW, SOD323 package, 45 Ω ZZT @ 5 mA | Lower power rating and higher impedance limit use in high-precision references | Select when board space is critical and 300 mW suffices; verify thermal margin on smaller SOD323 pad layout |
| MMBZ5251BS (ON Semiconductor) | 22 V, ±5%, 350 mW, SOT-23 package, 30 Ω ZZT @ 5 mA, non-AEC-Q101 | Lacks automotive qualification and has lower power rating than MMSZ5251B-7 | Prefer for commercial-grade consumer designs where AEC-Q101 is not required and SOT-23 footprint is preferred |
Compared with BZX584C22 and MMBZ5251BS, MMSZ5251B-7 offers superior power handling (370 mW), lower impedance (29 Ω), and AEC-Q101 qualification-making it optimal for automotive and industrial applications demanding robustness and precision.
Availability
MMSZ5251B-7 is available at Aetrix Electronics and suitable for switching power supplies, automotive ECUs, industrial sensor interfaces, and consumer overvoltage protection circuits requiring stable component supply and long-term manufacturability.
Supply support for MMSZ5251B-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, specializing in high-reliability, energy-efficient components for automotive, industrial, and computing markets.
The MMSZ52xxB series belongs to Diodes' general-purpose Zener diode product line, engineered for cost-effective, high-volume voltage regulation and reference applications with emphasis on AEC-Q101 compliance and green manufacturing.
FAQ
What is the maximum reverse voltage (VR) that MMSZ5251B-7 can withstand before breakdown?
The MMSZ5251B-7 begins controlled Zener breakdown at its nominal 22 V rating, with guaranteed operation between 20.9 V and 23.1 V at 5.6 mA test current. Its absolute maximum reverse voltage is not specified separately-it is designed to operate continuously in reverse breakdown within its power and thermal limits, not as a blocking diode.
Is MMSZ5251B-7 suitable for use in automotive applications?
Yes-MMSZ5251B-7 is explicitly qualified to AEC-Q101 standards, including high-temperature reverse bias (HTRB), temperature cycling (TCT), and highly accelerated life testing (HALT). Its −65 to +150 °C operating range and green, lead-free construction meet automotive electronics requirements.
How does the SOD123 package affect thermal performance compared to larger packages?
The SOD123 package delivers RθJA = 338 °C/W on FR-4 with 1-inch copper pad, enabling 370 mW dissipation at 25 °C ambient. While smaller than DO-35 or SOD-123FL variants, its standardized footprint supports automated placement and offers better thermal performance than SOD-323 (RθJA > 400 °C/W) for same power levels.
Can MMSZ5251B-7 replace older MMSZ5251 or MMSZ5251A variants?
Yes-MMSZ5251B-7 supersedes earlier revisions with identical electrical specifications, improved green molding compound (halogen/antimony-free), and tighter process controls. The "B" suffix denotes updated material content and qualification; pinout, package, and Zener characteristics remain fully compatible.
MMSZ5251B-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Voltage - Zener (Nom) (Vz):
- 22 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 29 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 17 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:
- SOD-123
MMSZ5251B-7 FAQ
1.How can I place an order for MMSZ5251B-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5251B-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 MMSZ5251B-7 reliable?
The price and inventory of MMSZ5251B-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5251B-7 is usually 5 days.
3.What payment methods are accepted for MMSZ5251B-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5251B-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5251B-7?
MMSZ5251B-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5251B-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 MMSZ5251B-7?
For technical support, including MMSZ5251B-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5251B-7 requirements.
6.How does Aetrix verify that MMSZ5251B-7 is sourced from the original manufacturer or authorized distributors?
All MMSZ5251B-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 MMSZ5251B-7 meets industry standards.
7.What is the process for return or replacement of MMSZ5251B-7?
All MMSZ5251B-7 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5251B-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 MMSZ5251B-7 part is unused and in its original packaging.
Return procedure for MMSZ5251B-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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