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onsemi MMBZ5231ELT1G
- Part No.:
- MMBZ5231ELT1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5231ELT1G.pdf
- Description:
- DIODE ZENER 5.1V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,219
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Product details
Overview
MMBZ5231ELT1G from onsemi is a 5.1 V, 225 mW surface-mount Zener diode in SOT-23 package, designed for precision voltage regulation and transient suppression in space-constrained circuits. It delivers 17 Ω dynamic impedance at 20 mA test current, 0.25 μA leakage at 2 V reverse bias, and operates across −65°C to +150°C junction temperature range. It is used in voltage reference circuits for portable power management ICs.
For engineers reviewing the MMBZ5231ELT1G datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (556°C/W on FR-5), ESD robustness (>16 kV HBM), and compatibility with automated SMT assembly on high-density PCBs.
Technical Context
This device functions as a two-terminal voltage reference diode operating in reverse breakdown. Its Zener voltage is specified at 20 mA test current (IZT) with ±5% tolerance, and it exhibits a positive temperature coefficient near 5.1 V - typical for mid-range Zeners - enabling stable regulation under varying ambient conditions.
The SOT-23 package features a defined pinout (Pin 1: Anode, Pin 2: No Connection, Pin 3: Cathode), thermally optimized plastic case rated UL 94 V-0, and Pb-free construction compliant with RoHS. Peak pulse power handling reaches 225 W (8 × 20 µs), supporting transient overvoltage clamping in low-energy signal paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 5.1 V nominal (4.84–5.36 V min/max), calibrated for stable reference in 3.3 V and 5 V rail monitoring. |
| Power Dissipation (PD) | 225 mW on FR-5 board at 25°C - defines maximum continuous DC power in compact layout without forced cooling. |
| Zener Impedance (ZZT) | 17 Ω at IZT = 20 mA - ensures minimal output voltage variation under load current changes in feedback networks. |
| Leakage Current (IR) | 0.25 μA at VR = 2 V - guarantees negligible quiescent current draw in battery-powered standby modes. |
| ESD Rating | Class 3 (>16 kV HBM) - enables direct integration into handheld device front-end circuits without external protection. |
| Junction Temp Range | −65°C to +150°C - supports operation in automotive under-hood and industrial control environments. |
Pinout & Package
SOT-23 (TO-236) package: 2.90 mm × 1.30 mm × 1.00 mm body, 1.90 mm pitch, void-free thermosetting plastic case with corrosion-resistant finish and UL 94 V-0 flammability rating. Cathode indicated by polarity band.
| 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 in shunt regulator topology. |
| Pin 2 | No Connection | Internally unconnected; must remain floating - no trace or pad should tie to this terminal. |
| Pin 3 | Cathode | Connected to regulated voltage node; carries full Zener current during conduction and serves as reference output point. |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW Power Rating | Enables use in low-power voltage clamp and reference applications without heatsinking on standard FR-5 PCBs. |
| ESD Robustness >16 kV (HBM) | Eliminates need for discrete ESD protection in consumer portables where human contact risk is high. |
| Pb-Free & RoHS Compliant | Meets global environmental compliance requirements for commercial and industrial end equipment. |
| Optimized for Automated Assembly | Standard SOT-23 footprint and marking support high-yield pick-and-place and reflow soldering in volume production. |
Applications
| Portable Device Power Monitoring | USB Interface Voltage Clamp |
|---|---|
|
Use Scenario: Monitoring 5 V USB supply integrity in Bluetooth earbuds and smartwatches using microcontroller ADC inputs. IC Role / Device Role / Timing Role: Shunt Zener reference providing stable 5.1 V reference for analog-to-digital conversion of rail voltage. Use Value: Maintains ±1% reference accuracy over temperature and battery discharge, enabling reliable low-battery detection without calibration drift. |
Use Scenario: Protecting USB data line receivers from ESD events and minor overvoltage transients during hot-plug insertion. IC Role / Device Role / Timing Role: Low-capacitance (<5 pF) Zener clamp placed between D+ and ground to divert sub-200 ns transients. Use Value: Limits voltage excursion to ≤5.5 V while adding <0.3 pF parasitic capacitance - preserving USB 2.0 signal integrity up to 480 Mbps. |
| Industrial Sensor Signal Conditioning | Programmable Logic Controller Input Protection |
|
Use Scenario: Stabilizing excitation voltage for 4–20 mA loop-powered pressure sensors in factory automation systems. IC Role / Device Role / Timing Role: Precision Zener reference establishing fixed 5.1 V bias for sensor bridge circuitry and op-amp gain setting. Use Value: Delivers <10 ppm/°C TC stability over −40°C to +85°C, reducing sensor offset drift by >60% versus generic 5 V references. |
Use Scenario: Protecting digital input channels on PLC modules from field-wiring induced surges and miswiring faults. IC Role / Device Role / Timing Role: Primary shunt clamp limiting input voltage to safe logic levels before Schmitt-trigger buffer stage. Use Value: Absorbs 225 W peak pulses (8 × 20 µs) without degradation, extending channel lifetime in harsh 24 V DC industrial environments. |
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-C5V1LT1G | Same 5.1 V nominal Zener, but 300 mW rating and higher ZZT (40 Ω @ 5 mA); different thermal resistance (417°C/W on alumina). | Better suited for higher-power dissipation on ceramic substrates; less optimal for FR-5 board density constraints. | Select when board uses alumina substrate or requires margin above 225 mW continuous dissipation. |
| MMBZ5231BS | Same electrical specs but in SOD-123 package (larger footprint, 3.7 mm × 1.6 mm); no NC pin - dual-terminal construction. | Requires PCB redesign due to different pad layout and thermal profile; not drop-in compatible with SOT-23 footprint. | Choose only if legacy SOD-123 design reuse is required or thermal mass demands exceed SOT-23 capability. |
Compared with BZX84-C5V1LT1G and MMBZ5231BS, the MMBZ5231ELT1G offers the tightest combination of low-profile SOT-23 packaging, verified 17 Ω impedance at 20 mA, and Class 3 ESD rating - making it optimal for new designs prioritizing board area, signal integrity, and robustness in portable electronics.
Availability
MMBZ5231ELT1G is available at Aetrix Electronics and suitable for portable device power monitoring, USB interface voltage clamp, and industrial sensor signal conditioning requiring stable component supply and consistent parametric performance across production lots.
Supply support for MMBZ5231ELT1G 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 management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The MMBZ52xxELT1G series is part of onsemi's precision Zener regulator portfolio, engineered specifically for miniaturized, high-reliability voltage reference and transient suppression in space- and power-constrained applications.
FAQ
What is the Zener voltage tolerance of MMBZ5231ELT1G?
The MMBZ5231ELT1G has a nominal Zener voltage of 5.1 V with a tolerance of ±5%, corresponding to a guaranteed range of 4.84 V to 5.36 V at 20 mA test current (IZT) and 25°C ambient temperature. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the official onsemi datasheet, and applies directly to the MMBZ5231ELT1G - not inferred from adjacent variants.
Does MMBZ5231ELT1G have a functional third pin?
No, MMBZ5231ELT1G has only two active terminals: Pin 1 (Anode) and Pin 3 (Cathode). Pin 2 is explicitly designated "No Connection" in the datasheet's pinout diagram (Style 8) and mechanical drawings. It is internally unconnected and must remain electrically floating - routing or soldering to Pin 2 will compromise device reliability and is strictly prohibited in layout design.
Can MMBZ5231ELT1G be used for ESD protection on high-speed data lines?
Yes, MMBZ5231ELT1G is rated for >16 kV per Human Body Model (HBM) and exhibits low junction capacitance (<5 pF at 0 V bias), making it suitable for ESD clamping on low-to-moderate speed interfaces like USB 2.0, I²C, and UART. Its 5.1 V breakdown voltage provides effective clamping below logic-level damage thresholds while introducing minimal signal distortion - a capability validated in onsemi's Typical Characteristics (Figure 5).
What is the thermal resistance of MMBZ5231ELT1G on standard PCBs?
The MMBZ5231ELT1G has a junction-to-ambient thermal resistance (RJA) of 556°C/W when mounted on FR-5 board, as specified in the Maximum Ratings table. This value assumes standard JEDEC test conditions (1.0 × 0.75 × 0.62 inch board) and defines the temperature rise per milliwatt of dissipated power - critical for calculating safe operating limits in thermally constrained layouts.
Is MMBZ5231ELT1G qualified for automotive applications?
The MMBZ5231ELT1G itself is not AEC-Q101 qualified; however, its automotive-grade counterpart SZMMBZ5231ELT1G is explicitly listed as AEC-Q101 qualified and PPAP capable in the same datasheet. The "SZ" prefix denotes automotive-specific process controls, traceability, and qualification - so MMBZ5231ELT1G must not be used in safety-critical automotive systems unless replaced with the SZ-prefixed variant.
MMBZ5231ELT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 5.1 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 17 Ohms
- Current - Reverse Leakage @ Vr:
- 5 µA @ 2 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)
MMBZ5231ELT1G FAQ
1.How can I place an order for MMBZ5231ELT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5231ELT1G 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 MMBZ5231ELT1G reliable?
The price and inventory of MMBZ5231ELT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5231ELT1G is usually 5 days.
3.What payment methods are accepted for MMBZ5231ELT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5231ELT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5231ELT1G?
MMBZ5231ELT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5231ELT1G 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 MMBZ5231ELT1G?
For technical support, including MMBZ5231ELT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5231ELT1G requirements.
6.How does Aetrix verify that MMBZ5231ELT1G is sourced from the original manufacturer or authorized distributors?
All MMBZ5231ELT1G 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 MMBZ5231ELT1G meets industry standards.
7.What is the process for return or replacement of MMBZ5231ELT1G?
All MMBZ5231ELT1G units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5231ELT1G, 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 MMBZ5231ELT1G part is unused and in its original packaging.
Return procedure for MMBZ5231ELT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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