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onsemi MMSZ5229BT1
- Part No.:
- MMSZ5229BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5229BT1.pdf
- Description:
- DIODE ZENER 4.3V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:4,466
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Product details
Overview
MMSZ5229BT1 from ON Semiconductor is a 500 mW, ±5% tolerance Zener diode in SOD−123 package with nominal reverse breakdown voltage of 4.3 V at 20 mA test current, 22 Ω dynamic impedance at IZT, and 5 µA maximum leakage current at 5 V reverse bias - used for precision voltage reference and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMSZ5229BT1 datasheet, pinout, applications, or equivalent options, this device serves as a surface-mount voltage clamp in power supply feedback paths, sensor biasing networks, and ESD-protected I/O conditioning where thermal equilibrium Zener regulation and Class 3 HBM ESD robustness (>16 kV) are required.
Technical Context
This Zener regulator operates with junction-to-ambient thermal resistance of 340 °C/W and junction-to-lead resistance of 150 °C/W, enabling stable 4.3 V regulation under thermal equilibrium conditions (TL = 30°C ±1°C). Its 500 mW power rating on FR-5 board supports continuous operation up to 75°C ambient before derating begins at 6.7 mW/°C.
The device exhibits a typical temperature coefficient near 0 mV/°C for its 4.3 V nominal voltage, confirmed by Figure 1 and Table 3 of the datasheet, and maintains ≤2000 Ω impedance at knee current (IZK = 0.25 mA), ensuring predictable low-current regulation behavior in standby or sleep-mode circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.09–4.52 V @ IZT = 20 mA - defines tight regulation window for 4.3 V nominal reference |
| Zener Impedance (ZZT) | 22 Ω max @ IZT = 20 mA - ensures minimal output voltage shift under load transients |
| Leakage Current (IR) | 5 µA max @ VR = 5 V - guarantees low quiescent current in high-impedance bias networks |
| Power Dissipation (PD) | 500 mW on FR-5 board @ TL = 75°C - sets maximum continuous DC power handling capability |
| ESD Rating | Class 3 (>16 kV) per HBM - provides robustness against human-body electrostatic discharge during handling and assembly |
| Junction Temp Range | −55°C to +150°C - supports operation in automotive under-hood and industrial control environments |
Pinout & Package
SOD−123 plastic surface-mount package (Case 425, Style 1), void-free thermosetting epoxy case with corrosion-resistant, solderable finish; cathode indicated by polarity band; 260°C max soldering temperature for 10 seconds; UL 94 V−0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener anode connection point | Connected to regulated voltage node; reverse-biased terminal where Zener breakdown occurs |
| 2 (Anode) | Zener cathode connection point | Connected to circuit ground or lower-potential rail; completes reverse-bias path for regulation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating | Enables use in medium-current voltage references without external heat sinking on standard PCBs |
| ±5% Zener Tolerance | Provides cost-effective precision for non-critical analog references where 4.3 V ±0.215 V is acceptable |
| Thermal Equilibrium Spec | Guarantees VZ accuracy measured at TL = 30°C ±1°C - critical for calibration-grade applications |
| Pb-Free Construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 |
Applications
| Power Supply Feedback Reference | Sensor Biasing Network |
|---|---|
Use Scenario: Stabilizing output voltage in adjustable linear regulators (e.g., LM317) via resistor divider feedback. IC Role / Device Role / Timing Role: Zener voltage reference element setting precise trip point for error amplifier comparison. Use Value: Delivers 4.3 V reference with <22 Ω dynamic impedance, minimizing output drift across load changes. | Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) or bridge sensors. IC Role / Device Role / Timing Role: Low-leakage (≤5 µA) voltage clamp establishing fixed bias potential independent of supply variation. Use Value: Ensures sensor output linearity by maintaining constant bias despite input rail fluctuations up to 5 V. |
| ESD-Protected I/O Clamping | Microcontroller Reset Circuit |
Use Scenario: Protecting UART, I²C, or GPIO pins from transient overvoltage events. IC Role / Device Role / Timing Role: Bidirectional clamping diode (with series resistor) limiting voltage to 4.3 V above ground. Use Value: Leverages >16 kV HBM ESD rating and fast Zener response to suppress spikes without latch-up risk. | Use Scenario: Generating clean reset signal for MCUs when main supply crosses 4.3 V threshold. IC Role / Device Role / Timing Role: Threshold detector in RC-based power-on reset (POR) circuit with hysteresis via pull-up. Use Value: Uses tight 4.09–4.52 V Zener window to ensure deterministic reset assertion timing across temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C4V3 | 4.3 V ±5%, 300 mW rating, SOD-323 package, 90 Ω ZZT | Lower power handling and higher impedance limit use in higher-current or tighter-regulation designs | Select when footprint size is constrained and 300 mW suffices; verify thermal margin in layout |
| 1N4733A | 5.1 V nominal, 1 W rating, DO-41 through-hole package, 17 Ω ZZT | Higher voltage, higher power, and leaded package incompatible with SMT-only production | Choose only for through-hole prototyping or legacy repair where 5.1 V is acceptable and board space allows |
Compared with BZX584C4V3 and 1N4733A, the MMSZ5229BT1 offers optimal balance of SMT compatibility, 500 mW capability, and 22 Ω low-impedance regulation at 4.3 V - making it preferred for modern compact power management and sensor interface designs requiring surface-mount reliability and thermal equilibrium accuracy.
Availability
MMSZ5229BT1 is available at Aetrix Electronics and suitable for power supply feedback references, sensor biasing networks, ESD-protected I/O clamping, and microcontroller reset circuits requiring stable component supply with full traceability and lifecycle support.
Supply support for MMSZ5229BT1 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MMSZ52xxxT1G series was designed for general-purpose, medium-current Zener regulation in high-density surface-mount applications - emphasizing thermal equilibrium accuracy, Pb-free compliance, and robust ESD performance in compact SOD−123 packaging.
FAQ
What is the nominal Zener voltage and tolerance of the MMSZ5229BT1?
The MMSZ5229BT1 has a nominal Zener voltage of 4.3 V with a ±5% tolerance, meaning its actual breakdown voltage falls between 4.09 V and 4.52 V when tested at 20 mA (IZT) under thermal equilibrium conditions (TL = 30°C ±1°C), as specified in the Electrical Characteristics table on page 3 of the datasheet.
Does the MMSZ5229BT1 meet automotive qualification standards?
The MMSZ5229BT1 itself is not automotive-qualified; however, the SZMMSZ5229BT1G variant (with SZ prefix) is AEC-Q101 qualified and PPAP capable. The MMSZ5229BT1 is intended for general-purpose industrial and commercial applications, with identical electrical specs but without the automotive-specific process controls and documentation.
What is the maximum reverse leakage current for the MMSZ5229BT1, and at what voltage is it specified?
The MMSZ5229BT1 has a maximum reverse leakage current (IR) of 5 µA, specified at a reverse voltage (VR) of 5 V and ambient temperature of 25°C. This low leakage supports use in high-impedance bias networks where current draw must be minimized, such as RTD excitation or precision reference dividers.
Can the MMSZ5229BT1 be used in place of a 5.1 V Zener like the 1N4733A?
No - the MMSZ5229BT1 is rated for 4.3 V nominal Zener voltage and is not a functional replacement for the 5.1 V 1N4733A. Substituting it would shift regulation thresholds by ~0.8 V, potentially causing incorrect operation in feedback loops or reset circuits calibrated for 5.1 V. Always match nominal Zener voltage within system requirements.
What is the thermal resistance from junction to ambient (RJA) for the MMSZ5229BT1, and how does it affect power derating?
The MMSZ5229BT1 has a junction-to-ambient thermal resistance (RJA) of 340 °C/W on FR-5 board. At ambient temperatures above 75°C, its 500 mW power rating must be derated at 6.7 mW/°C - meaning at 100°C ambient, maximum allowable dissipation drops to 332.5 mW to maintain safe junction temperature below 150°C.
MMSZ5229BT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±5%
- Power - Max:
- 500 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:
- SOD-123
MMSZ5229BT1 FAQ
1.How can I place an order for MMSZ5229BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5229BT1 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 MMSZ5229BT1 reliable?
The price and inventory of MMSZ5229BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5229BT1 is usually 5 days.
3.What payment methods are accepted for MMSZ5229BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5229BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5229BT1?
MMSZ5229BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5229BT1 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 MMSZ5229BT1?
For technical support, including MMSZ5229BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5229BT1 requirements.
6.How does Aetrix verify that MMSZ5229BT1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5229BT1 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 MMSZ5229BT1 meets industry standards.
7.What is the process for return or replacement of MMSZ5229BT1?
All MMSZ5229BT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5229BT1, 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 MMSZ5229BT1 part is unused and in its original packaging.
Return procedure for MMSZ5229BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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