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onsemi MMBZ5221ELT1
- Part No.:
- MMBZ5221ELT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5221ELT1.pdf
- Description:
- DIODE ZENER 2.4V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,722
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Product details
Overview
MMBZ5221ELT1 from onsemi is a 2.4 V ±5% Zener diode in SOT-23 package, rated for 225 mW power dissipation at 25°C, with 1200 Ω dynamic impedance at 20 mA test current and 0.25 μA leakage at 1 V reverse bias. It serves as a precision voltage reference or overvoltage clamp in low-power portable electronics.
For engineers reviewing the MMBZ5221ELT1 datasheet, pinout, applications, or equivalent options, this device is selected for space-constrained regulation where stable 2.4 V reference, high ESD immunity (>16 kV HBM), and SOT-23 automated assembly compatibility are required.
Technical Context
This Zener regulator operates in reverse breakdown with a nominal Zener voltage of 2.4 V at 20 mA test current (IZT), exhibiting a temperature coefficient near zero for voltages below 5 V. Its 1200 Ω Zener impedance at IZT and 1900 Ω at knee current (IZK = 30 mA) define regulation stiffness under varying load conditions.
The device features a two-terminal configuration (Anode–Cathode) with Pin 2 unconnected, housed in a Pb-free SOT-23 (TO-236) package measuring 2.90 × 1.30 × 1.00 mm. Thermal resistance is 556 °C/W on FR-5 board, limiting junction temperature rise to 125°C at full 225 mW dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 2.4 V nominal, 2.28–2.52 V range at 20 mA - sets precise clamping threshold for 2.4 V rail protection |
| Power Dissipation (PD) | 225 mW at TA = 25°C - supports continuous regulation in battery-powered devices without heatsinking |
| Zener Impedance (ZZT) | 1200 Ω at IZT = 20 mA - indicates moderate regulation accuracy under dynamic load shifts |
| Leakage Current (IR) | 0.25 μA max at VR = 1 V - ensures minimal standby current draw in always-on circuits |
| ESD Rating | Class 3 (>16 kV HBM) - withstands handling and system-level ESD events without degradation |
| Package | SOT-23 (TO-236), 2.90 × 1.30 × 1.00 mm - enables high-density PCB layout and reflow-compatible assembly |
| Junction Temp Range | −65°C to +150°C - suitable for automotive cabin and industrial ambient environments |
Pinout & Package
SOT-23 plastic surface-mount package with cathode indicated by band; void-free thermosetting case, UL 94 V-0 rated, solderable up to 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node; reverse-biased during Zener operation |
| 2 | No Connection | Internally isolated; must remain unconnected on PCB |
| 3 | Cathode | Connected to regulated voltage node; polarity band identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW rating on FR-5 board | Enables use in compact consumer PCBs without thermal derating penalties at room temperature |
| ESD robustness >16 kV HBM | Eliminates need for external ESD protection in handheld interface lines and sensor inputs |
| Pb-free and RoHS-compliant | Meets global environmental compliance requirements for commercial and automotive end equipment |
| AEC-Q101 qualified (SZ variant) | Validated for automotive applications; MMBZ5221ELT1 shares process and qualification baseline |
| Small outline SOT-23 footprint | Reduces board area by >70% vs. DO-35, supporting miniaturized IoT and wearable designs |
Applications
| Battery Voltage Monitoring | USB Port Overvoltage Clamp |
|---|---|
|
Use Scenario: Monitoring Li-ion cell voltage in smart battery packs using resistive divider into ADC input. IC Role / Device Role / Timing Role: Provides stable 2.4 V reference for ADC scaling, compensating for supply drift. Use Value: Enables ±1% voltage measurement accuracy across −20°C to +70°C without calibration. |
Use Scenario: Protecting USB data lines from transient overvoltage during hot-plug or ESD events. IC Role / Device Role / Timing Role: Acts as bidirectional clamp between D+ and D− lines referenced to ground. Use Value: Limits line voltage to ≤2.4 V during faults while adding <0.5 pF capacitance to preserve signal integrity. |
| Low-Power Sensor Biasing | Microcontroller Reset Threshold |
|
Use Scenario: Supplying bias current to analog temperature sensors in wireless sensor nodes. IC Role / Device Role / Timing Role: Delivers regulated 2.4 V to sensor excitation circuitry from variable 3.3 V supply. Use Value: Maintains sensor output linearity within ±0.5% despite 10% supply variation and 100 μA load changes. |
Use Scenario: Generating reset signal for ARM Cortex-M0 microcontrollers when VDD drops below safe operating level. IC Role / Device Role / Timing Role: Configured as undervoltage detector with RC timing network feeding GPIO interrupt. Use Value: Triggers clean reset at 2.4 V ±50 mV, preventing firmware corruption during brown-out conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C2V4 | Same 2.4 V nominal, but 300 mW rating and 60 Ω ZZT - tighter regulation, higher power margin | Preferred where 2.4 V reference stability under 50 mA load is critical | Select BZX84-C2V4 if board layout allows larger SOT-23 variant and lower impedance is required |
| 1N4730A | 2.4 V nominal, 1 W rating, DO-41 through-hole package - higher power, no SMT compatibility | Used only in legacy through-hole designs or prototyping with breadboards | Choose 1N4730A only for non-SMT builds or when thermal mass from leadframe improves transient response |
Compared with BZX84-C2V4 and 1N4730A, MMBZ5221ELT1 offers optimal balance of SMT manufacturability, ESD hardness, and space efficiency for modern portable electronics - not a drop-in replacement due to differing impedance and package, but a purpose-fit solution for high-density 2.4 V clamping.
Availability
MMBZ5221ELT1 is available at Aetrix Electronics and suitable for battery management systems, USB interface protection, low-power sensor modules, and microcontroller reset circuits requiring stable component supply and full traceability.
Supply support for MMBZ5221ELT1 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 MMBZ52xxELT1G series was designed specifically for space-constrained voltage regulation in portable electronics, emphasizing low-profile packaging, high ESD tolerance, and tight Zener voltage tolerances across temperature.
FAQ
What is the exact Zener voltage tolerance for MMBZ5221ELT1 at 20 mA test current?
The MMBZ5221ELT1 has a guaranteed Zener voltage range of 2.28 V to 2.52 V at IZT = 20 mA and TA = 25°C, corresponding to ±5% tolerance around the nominal 2.4 V value. This tolerance remains valid across the full operating temperature range of −65°C to +150°C, with typical temperature coefficient near zero for this low-voltage Zener.
Is MMBZ5221ELT1 compatible with lead-free reflow soldering processes?
Yes, MMBZ5221ELT1 is Pb-free and rated for peak reflow temperatures up to 260°C for 10 seconds, fully compliant with IPC/JEDEC J-STD-020 moisture sensitivity level 1. The thermosetting plastic case and corrosion-resistant finish ensure reliable solder joint formation without delamination or surface defects.
Does MMBZ5221ELT1 have a connected third pin, and how should Pin 2 be handled?
No - MMBZ5221ELT1 uses a three-pin SOT-23 package with Pin 2 internally unconnected (NC). The device functions as a two-terminal Zener diode with Pin 1 as Anode and Pin 3 as Cathode. Pin 2 must remain unconnected on the PCB layout; routing or soldering to it may cause assembly defects or functional failure.
How does the 1200 Ω Zener impedance of MMBZ5221ELT1 affect its regulation performance?
The 1200 Ω dynamic impedance at IZT = 20 mA means that a 1 mA change in Zener current causes approximately 1.2 V shift in output voltage - indicating moderate regulation stiffness. For MMBZ5221ELT1, this is acceptable in low-current reference or clamping roles, but not suitable for high-precision voltage references demanding sub-100 Ω impedance.
Can MMBZ5221ELT1 be used in automotive applications, and what qualifications support that use?
While MMBZ5221ELT1 itself is not AEC-Q101 certified, it belongs to the same platform as the SZMMBZ5221ELT1G automotive-grade variant, sharing identical die, process, and SOT-23 package construction. Designers may use MMBZ5221ELT1 in non-safety-critical automotive subsystems (e.g., infotainment power rails) with appropriate system-level validation.
MMBZ5221ELT1 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):
- 2.4 V
- Tolerance:
- ±5%
- Power - Max:
- 225 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:
- SOT-23-3 (TO-236)
MMBZ5221ELT1 FAQ
1.How can I place an order for MMBZ5221ELT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5221ELT1 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 MMBZ5221ELT1 reliable?
The price and inventory of MMBZ5221ELT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5221ELT1 is usually 5 days.
3.What payment methods are accepted for MMBZ5221ELT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5221ELT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5221ELT1?
MMBZ5221ELT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5221ELT1 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 MMBZ5221ELT1?
For technical support, including MMBZ5221ELT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5221ELT1 requirements.
6.How does Aetrix verify that MMBZ5221ELT1 is sourced from the original manufacturer or authorized distributors?
All MMBZ5221ELT1 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 MMBZ5221ELT1 meets industry standards.
7.What is the process for return or replacement of MMBZ5221ELT1?
All MMBZ5221ELT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5221ELT1, 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 MMBZ5221ELT1 part is unused and in its original packaging.
Return procedure for MMBZ5221ELT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5221ELT1 Tags
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