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onsemi MMSZ5221ET1
- Part No.:
- MMSZ5221ET1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5221ET1.pdf
- Description:
- DIODE ZENER 2.4V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:8,363
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Product details
Overview
MMSZ5221ET1 from onsemi is a 2.4 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 20 mA test current, 1200 Ω maximum dynamic impedance at IZT, and 0.25 µA leakage current at 100 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power analog and digital supply regulation circuits.
For engineers reviewing the MMSZ5221ET1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, SOD-123 terminal mapping, ESD robustness (Class 3, >16 kV HBM), and validated alternatives for voltage reference design-in.
Technical Context
This device operates in reverse-biased Zener breakdown mode to maintain stable voltage across its terminals under varying load or line conditions. Its 2.4 V nominal Zener voltage is specified at 20 mA test current (IZT) with ±5% tolerance, and it exhibits a temperature coefficient of approximately +2.5 mV/°C near this voltage level.
Thermal performance is defined by junction-to-ambient thermal resistance of 340 °C/W and junction-to-lead resistance of 150 °C/W. Peak surge capability reaches 225 W for nonrepetitive 8 × 20 µs pulses, supporting transient suppression in compact PCB layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 2.4 V nominal, 2.28–2.52 V range at 20 mA - defines stable clamping/reference point for low-voltage rails |
| Power Dissipation (PD) | 500 mW at TL = 75 °C - sets continuous operating limit on standard FR-5 board |
| Zener Impedance (ZZT) | ≤1200 Ω at IZT = 20 mA - indicates voltage regulation stability under moderate current variation |
| Leakage Current (IR) | ≤0.25 µA at VR = 100 V - ensures minimal standby current in high-impedance bias networks |
| ESD Rating | Class 3 (>16 kV) per HBM - supports handling and assembly without special ESD controls |
| Package | SOD-123 (1.60 × 2.69 × 1.16 mm) - enables high-density surface-mount placement with automated pick-and-place |
Pinout & Package
SOD-123 is a 2-lead surface-mount plastic package with cathode indicated by a polarity band. Lead 1 is cathode; lead 2 is anode. The case is void-free thermosetting plastic with UL 94 V-0 flammability rating and corrosion-resistant, solderable finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated output node or voltage reference point; reverse-bias terminal during Zener operation |
| 2 (Non-banded End) | Anode | Typically tied to ground or lower-potential rail; completes current path during regulation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating on FR-5 Board | Enables use in space-constrained consumer and industrial PCBs without heatsinking |
| ±5% Zener Voltage Tolerance | Supports cost-sensitive designs where tight voltage accuracy is not required |
| ESD Robustness (Class 3, >16 kV HBM) | Reduces need for external ESD protection in handheld and portable electronics |
| Peak Surge Power: 225 W (8 × 20 µs) | Provides transient immunity against common electrostatic and switching surges |
| Pb-Free Construction | Meets RoHS compliance requirements for global commercial and industrial shipments |
Applications
| Low-Voltage Microcontroller Reference | USB Port Overvoltage Clamp |
|---|---|
Use Scenario: Providing stable 2.4 V reference for ADC input scaling or internal LDO feedback in battery-powered MCU systems. IC Role / Device Role / Timing Role: Precision voltage reference diode establishing fixed analog reference point independent of supply variation. Use Value: Maintains <±1% reference drift over temperature due to predictable TC and low ZZT, enabling consistent 10-bit ADC resolution. | Use Scenario: Clamping USB VBUS line against ESD events or hot-plug transients in embedded host controllers. IC Role / Device Role / Timing Role: Fast-acting shunt protector diverting surge current away from sensitive USB PHY circuitry. Use Value: Withstands 225 W nonrepetitive surges and >16 kV HBM ESD, meeting IEC 61000-4-2 Level 4 immunity requirements. |
| Industrial Sensor Bias Network | Legacy Logic-Level Translation |
Use Scenario: Generating precise bias voltage for analog sensor front-ends (e.g., RTD bridges or op-amp gain-setting networks). IC Role / Device Role / Timing Role: Low-leakage (<0.25 µA) Zener providing stable DC offset in high-impedance signal conditioning paths. Use Value: Minimal leakage avoids loading effects on 10 MΩ+ sensor networks, preserving measurement accuracy and long-term stability. | Use Scenario: Level-shifting between 3.3 V logic and 2.4 V tolerant interface pins in mixed-voltage FPGA or ASIC I/O banks. IC Role / Device Role / Timing Role: Passive clamping element limiting high-side voltage to safe 2.4 V threshold while allowing full swing below that point. Use Value: Enables interoperability without active translators; low capacitance (~30 pF at 0 V bias) preserves signal edge integrity up to 10 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C2V4 | 2.4 V ±5%, SOD-323 package, 300 mW rating, 1000 Ω ZZT at 5 mA | Lower power rating and different test current require layout and thermal re-evaluation | Preferred where board area is more constrained than power margin |
| MMBZ5221BS | 2.4 V ±5%, SOT-23 package, 350 mW rating, 1200 Ω ZZT at 20 mA | Three-terminal SOT-23 footprint requires pad redesign; same Zener spec but higher thermal resistance | Chosen when existing SOT-23 land pattern must be reused |
Compared with MMSZ5221ET1, BZX584C2V4 offers smaller size but reduced power handling, while MMBZ5221BS retains identical Zener parameters but demands PCB layout changes-making MMSZ5221ET1 optimal for new designs prioritizing thermal margin and SOD-123 automation compatibility.
Availability
MMSZ5221ET1 is available at Aetrix Electronics and suitable for low-voltage reference generation, ESD protection clamping, and sensor biasing applications requiring stable component supply and RoHS-compliant sourcing.
Supply support for MMSZ5221ET1 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 MMSZ52xxET1G series targets general-purpose, medium-current Zener regulation in space-constrained surface-mount applications, emphasizing manufacturability, ESD resilience, and thermal reliability on standard PCB substrates.
FAQ
What is the Zener voltage tolerance for MMSZ5221ET1?
The MMSZ5221ET1 has a nominal Zener voltage of 2.4 V with a standard tolerance of ±5%, resulting in a guaranteed range of 2.28 V to 2.52 V when measured at 20 mA test current and thermal equilibrium at 30 °C. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the official onsemi datasheet for MMSZ5221ET1.
What is the maximum power dissipation of MMSZ5221ET1 on FR-5 board?
The MMSZ5221ET1 is rated for 500 mW total power dissipation on FR-5 board at lead temperature (TL) = 75 °C, with linear derating of 6.7 mW/°C above that temperature. This rating assumes use of the minimum recommended footprint (3.5 × 1.5 inches) and is distinct from its 225 W peak surge capability for short-duration pulses.
Does MMSZ5221ET1 have automotive qualification?
No - the base MMSZ5221ET1 is not AEC-Q101 qualified. However, the SZ-prefix variant SZMMSZ5221ET1G is specifically designed for automotive and other applications requiring unique site and control change requirements, and it is AEC-Q101 qualified and PPAP capable. Engineers selecting for automotive use must specify the SZMMSZ5221ET1G part number.
What is the Zener impedance of MMSZ5221ET1 at its test current?
The MMSZ5221ET1 has a maximum Zener impedance (ZZT) of 1200 Ω at the specified test current of 20 mA (IZT). This value is measured using 1 kHz AC signal with IZ(AC) = 0.1 × IZ(DC), and reflects the device's ability to maintain stable voltage under small-signal dynamic load variations.
How is polarity marked on the MMSZ5221ET1 SOD-123 package?
The MMSZ5221ET1 uses a cathode band to indicate polarity on the SOD-123 package - the banded end corresponds to Pin 1 (cathode), and the non-banded end is Pin 2 (anode). This marking aligns with JEDEC-standard SOD-123 orientation and is visible under standard optical inspection during automated assembly.
MMSZ5221ET1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 30 Ohms
- Current - Reverse Leakage @ Vr:
- 100 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
MMSZ5221ET1 FAQ
1.How can I place an order for MMSZ5221ET1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5221ET1 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 MMSZ5221ET1 reliable?
The price and inventory of MMSZ5221ET1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5221ET1 is usually 5 days.
3.What payment methods are accepted for MMSZ5221ET1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5221ET1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5221ET1?
MMSZ5221ET1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5221ET1 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 MMSZ5221ET1?
For technical support, including MMSZ5221ET1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5221ET1 requirements.
6.How does Aetrix verify that MMSZ5221ET1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5221ET1 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 MMSZ5221ET1 meets industry standards.
7.What is the process for return or replacement of MMSZ5221ET1?
All MMSZ5221ET1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5221ET1, 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 MMSZ5221ET1 part is unused and in its original packaging.
Return procedure for MMSZ5221ET1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMSZ5221ET1 Tags
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BZT52C5V6T-7
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BZX84C3V3LT1G
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MMSZ4682T1G
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BZT52C15S-7-F
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MM5Z5V1ST1G
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