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onsemi MMBZ5229BLT3
- Part No.:
- MMBZ5229BLT3
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5229BLT3.pdf
- Description:
- DIODE ZENER 4.3V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,411
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Product details
Overview
MMBZ5229BLT3 from onsemi is a 4.3 V ±5% Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board, with 22 Ω dynamic impedance at 20 mA test current and 5 μA leakage current at 1 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power portable electronics.
For engineers reviewing the MMBZ5229BLT3 datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal resistance (556 °C/W), ESD rating (>16 kV HBM), cathode-anode polarity marking, and compatibility with automated SMT assembly on high-density PCBs.
Technical Context
This device operates as a two-terminal voltage-regulating diode with sharp reverse breakdown at nominal 4.3 V. Its Zener impedance of 22 Ω at IZT = 20 mA ensures stable regulation under moderate load transients, while its 556 °C/W junction-to-ambient thermal resistance defines derating behavior above 25°C ambient.
The SOT-23 package features a defined pinout: Pin 1 = Anode, Pin 2 = No Connection, Pin 3 = Cathode - confirmed by mechanical outline Style 8 and electrical characteristics table. Polarity is marked by a band on the cathode end, consistent with JEDEC TO-236 standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.3 V nominal, 4.08–4.52 V range at 20 mA - sets precise clamping threshold for 3.3 V or 5 V rail protection. |
| Power Dissipation (PD) | 225 mW on FR-5 board at 25°C - supports compact, low-heat designs without heatsinking in handheld devices. |
| Zener Impedance (ZZT) | 22 Ω max at IZT = 20 mA - ensures minimal output voltage shift under varying load current in reference circuits. |
| Leakage Current (IR) | 5 μA max at VR = 1 V - guarantees negligible standby current draw in battery-powered systems. |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - enables robust handling during manual assembly and field operation. |
| Junction Temperature Range | −65°C to +150°C - supports operation in automotive under-hood and industrial environments. |
Pinout & Package
SOT-23 (TO-236) surface-mount package, 2.90 × 1.30 × 1.00 mm, void-free thermosetting plastic case with corrosion-resistant finish. Cathode indicated by polarity band; maximum soldering temperature 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Anode | Connected to lower-potential node in reverse-bias configuration; must be routed to ground or return path for clamping. |
| Pin 2 | No Connection | Internally unconnected; no PCB trace or pad required - simplifies layout and avoids accidental shorts. |
| Pin 3 | Cathode | Connected to regulated node or protected input; polarity band aligns with this terminal for visual orientation. |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW power rating on FR-5 board | Enables use in space-constrained consumer PCBs without thermal derating penalties up to 25°C ambient. |
| ESD rating >16 kV HBM | Eliminates need for external ESD protection in front-end signal conditioning stages of portable gear. |
| Pb-free, Halogen-free/BFR-free, RoHS compliant | Meets global environmental compliance requirements for commercial and industrial end products. |
| Optimized SOT-23 footprint for automated assembly | Supports high-speed pick-and-place with standard vision alignment; compatible with IPC-7351B land patterns. |
Applications
| USB Port Protection | Microcontroller I/O Clamp |
|---|---|
Use Scenario: Protecting USB 2.0 data lines (D+/D−) from ESD events and transient overvoltage. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between signal line and ground, conducting only when voltage exceeds ±4.3 V. Use Value: Limits peak voltage to safe levels for USB transceivers while adding <1 pF parasitic capacitance - preserving signal integrity at 480 Mbps. |
Use Scenario: Safeguarding GPIO pins of ARM Cortex-M microcontrollers against overvoltage during hot-plug or level-shifting. IC Role / Device Role / Timing Role: Low-leakage Zener connected between I/O pin and ground, clamping excursions beyond supply rail. Use Value: Prevents latch-up and gate oxide damage with 5 μA leakage at 1 V - no impact on sleep-mode current budget. |
| Li-ion Battery Monitoring | Low-Power Sensor Reference |
Use Scenario: Providing stable 4.3 V reference for fuel gauge ICs monitoring single-cell Li-ion battery voltage. IC Role / Device Role / Timing Role: Precision shunt reference in resistor-divider feedback network for ADC input scaling. Use Value: Delivers ±5% voltage accuracy across −40°C to +85°C, enabling accurate state-of-charge estimation within 2% error. |
Use Scenario: Generating a stable bias point for analog sensor signal conditioning in wearable health monitors. IC Role / Device Role / Timing Role: Low-noise Zener supplying reference voltage to op-amp non-inverting input in instrumentation amplifier stage. Use Value: 22 Ω dynamic impedance minimizes noise coupling into 24-bit sigma-delta ADC paths, maintaining ENOB >20 bits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C4V3 | Same 4.3 V nominal Zener, but 350 mW rating and higher ZZT (60 Ω); SOT-23 package with identical pinout. | Higher power handling suits higher-current clamping; less suitable for ultra-low-leakage (<10 μA) battery monitoring. | Select BZX84-C4V3 when >225 mW dissipation is needed; verify layout compatibility with same footprint. |
| MMBZ5229BS | Same electrical specs, but in SOD-323 (SC-76) package - smaller footprint (1.7 × 1.25 mm), higher thermal resistance (625 °C/W). | Better suited for ultra-high-density layouts where board area is critical; requires tighter thermal management. | Choose MMBZ5229BS only if SOD-323 placement and reflow profile are validated; not drop-in for SOT-23 footprints. |
Compared with MMBZ5229BLT3, BZX84-C4V3 offers higher power margin but looser regulation stability, while MMBZ5229BS trades thermal performance for miniaturization - making MMBZ5229BLT3 the balanced choice for general-purpose 4.3 V clamping in SOT-23-based designs.
Availability
MMBZ5229BLT3 is available at Aetrix Electronics and suitable for USB port protection, microcontroller I/O clamping, and Li-ion battery monitoring requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for MMBZ5229BLT3 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MMBZ52xxBLT3 series belongs to onsemi's Zener voltage regulator product line, engineered for space-constrained, high-reliability applications demanding precise voltage clamping with robust ESD immunity and lead-free compliance.
FAQ
What is the exact Zener voltage tolerance for MMBZ5229BLT3?
The MMBZ5229BLT3 has a nominal Zener voltage of 4.3 V with a guaranteed range of 4.08 V to 4.52 V at 20 mA test current (IZT), corresponding to ±5% tolerance. This specification is verified per onsemi's Electrical Characteristics table and applies at 25°C ambient temperature with pulse testing to minimize self-heating effects.
Does MMBZ5229BLT3 have a built-in ESD protection rating?
Yes, MMBZ5229BLT3 is rated Class 3 for ESD per Human Body Model (HBM) with >16 kV withstand capability. This rating is explicitly stated in the Features section of the official datasheet and reflects device-level qualification - not board-level system performance.
What is the thermal resistance of MMBZ5229BLT3 on standard PCB material?
The junction-to-ambient thermal resistance (RJA) of MMBZ5229BLT3 is 556 °C/W when mounted on an FR-5 board. This value assumes standard JEDEC test conditions (1.0 × 0.75 × 0.62 inch board) and defines the linear derating slope of 1.8 mW/°C above 25°C ambient temperature.
Is Pin 2 of MMBZ5229BLT3 electrically connected internally?
No, Pin 2 of MMBZ5229BLT3 is a no-connect (NC) terminal - it is not bonded to any internal die structure and must remain unconnected on the PCB. This is confirmed in both the Marking Diagram section and the Mechanical Characteristics table specifying Style 8 pinout (Pin 1 = Anode, Pin 2 = NC, Pin 3 = Cathode).
Can MMBZ5229BLT3 be used as a replacement for MMBZ5229BLT1G?
Yes, MMBZ5229BLT3 is functionally identical to MMBZ5229BLT1G in electrical and thermal specifications, differing only in packaging quantity (10,000/reel vs. 3,000/reel) and tape-and-reel orientation. Both share the same SOT-23 package, marking code "8D", and Pb-free construction - making them interchangeable in design and manufacturing.
MMBZ5229BLT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 22 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
MMBZ5229BLT3 FAQ
1.How can I place an order for MMBZ5229BLT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5229BLT3 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 MMBZ5229BLT3 reliable?
The price and inventory of MMBZ5229BLT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5229BLT3 is usually 5 days.
3.What payment methods are accepted for MMBZ5229BLT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5229BLT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5229BLT3?
MMBZ5229BLT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5229BLT3 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 MMBZ5229BLT3?
For technical support, including MMBZ5229BLT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5229BLT3 requirements.
6.How does Aetrix verify that MMBZ5229BLT3 is sourced from the original manufacturer or authorized distributors?
All MMBZ5229BLT3 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 MMBZ5229BLT3 meets industry standards.
7.What is the process for return or replacement of MMBZ5229BLT3?
All MMBZ5229BLT3 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5229BLT3, 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 MMBZ5229BLT3 part is unused and in its original packaging.
Return procedure for MMBZ5229BLT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5229BLT3 Tags
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