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onsemi MMBZ5251BLT1G
- Part No.:
- MMBZ5251BLT1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5251BLT1G.pdf
- Description:
- DIODE ZENER 22V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,262
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Product details
Overview
MMBZ5251BLT1G from onsemi is a 22 V Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board, with 5.6 mA test current, 29 Ω dynamic impedance at IZT, and 0.1 µA leakage current at 17 V reverse bias. It provides precision voltage regulation in space-constrained portable electronics and high-density PCBs.
For engineers reviewing the MMBZ5251BLT1G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, ESD robustness (Class 3, >16 kV HBM), and real-world use context for low-power voltage reference and overvoltage protection design.
Technical Context
This device operates as a two-terminal voltage reference diode with cathode-anode polarity, requiring no external bias circuitry. Its Zener breakdown is specified at 5.6 mA test current (IZT) and exhibits a nominal temperature coefficient of +4.5 mV/°C across −55°C to +150°C ambient range.
The SOT-23 package supports automated placement and reflow soldering up to 260°C for 10 seconds. Thermal resistance is 556°C/W on FR-5 board and 417°C/W on alumina substrate, enabling predictable junction temperature rise under defined power loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 20.9 V min / 22 V nom / 23.1 V max @ IZT = 5.6 mA - defines stable regulation window for 22 V reference designs |
| Power Dissipation (PD) | 225 mW @ TA = 25°C on FR-5 board - sets maximum continuous DC power before thermal derating applies |
| Zener Impedance (ZZT) | 29 Ω max @ IZT = 5.6 mA - determines output voltage stability under load transients |
| Leakage Current (IR) | 0.1 µA max @ VR = 17 V - ensures minimal standby current in undervoltage detection circuits |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - enables direct integration into handheld device front-end without added ESD 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) surface-mount package, 2.90 mm × 1.30 mm × 1.00 mm, Pb-free and RoHS compliant. Cathode indicated by band; pin 2 is internally unconnected.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | DC input terminal; connects to lower-potential node in reverse-bias regulation configuration |
| 2 | No Connection | Internally isolated; must remain floating - no PCB trace or pad required |
| 3 | Cathode | Regulated output terminal; referenced to system ground or supply rail in shunt regulator topology |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile SOT-23 packaging | Enables placement on 0.5 mm pitch PCBs and integration into ultra-thin mobile devices |
| 225 mW FR-5 board rating | Supports stable 22 V reference generation without heatsinking in compact layouts |
| Class 3 ESD robustness | Eliminates need for discrete TVS diodes in consumer USB and audio interface protection |
| Pb-free, Halogen-free, RoHS-compliant | Meets global environmental compliance requirements for medical and industrial end equipment |
Applications
| Portable Power Monitoring | USB Interface Protection |
|---|---|
Use Scenario: Voltage supervision in Bluetooth earbuds during battery discharge from 4.2 V to 3.0 V. IC Role / Device Role / Timing Role: Shunt Zener reference for ADC input scaling and low-battery flag generation. Use Value: Maintains ±5% regulation accuracy across temperature while consuming <0.1 µA in sleep mode. |
Use Scenario: Overvoltage clamp on USB 2.0 D+ line exposed to ESD events during hot-plug insertion. IC Role / Device Role / Timing Role: Fast-response transient suppressor limiting line voltage to ≤23.1 V during 15 kV HBM discharge. Use Value: Prevents damage to USB PHY ICs without adding series resistance that degrades signal integrity. |
| Industrial Sensor Signal Conditioning | Automotive Cabin Control Panel |
Use Scenario: Reference stabilization for 12-bit analog front-end measuring 4–20 mA loop current in factory automation. IC Role / Device Role / Timing Role: Precision 22 V Zener providing stable bias for op-amp gain-setting resistors. Use Value: Limits reference drift to <0.01%/°C over −40°C to +85°C operating range. |
Use Scenario: Reverse-polarity and load-dump protection for LED backlight driver in infotainment display. IC Role / Device Role / Timing Role: Clamping diode absorbing 12 V system transients up to 225 mW for 100 ms duration. Use Value: Survives ISO 7637-2 Pulse 1 and Pulse 4a waveforms without degradation or parameter shift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C22LT1G | Same 22 V nominal Zener, but 350 mW rating on FR-4 board and 30 Ω ZZT @ 5 mA - higher power handling, slightly higher impedance | Preferred where board layout allows larger thermal relief or where higher surge energy absorption is needed | Select BZX84-C22LT1G when >225 mW continuous dissipation is required; verify SOT-23 footprint compatibility |
| SZMMBZ5251BLT1G | Identical electrical specs and package, but AEC-Q101 qualified and PPAP capable - same Zener voltage, impedance, and leakage | Required for automotive production programs needing certified component traceability and process control | Choose SZMMBZ5251BLT1G for Tier 1 automotive designs; MMBZ5251BLT1G remains valid for industrial and consumer use |
Compared with BZX84-C22LT1G, MMBZ5251BLT1G offers tighter thermal management in ultra-thin assemblies due to lower PD and optimized FR-5 derating; compared with SZMMBZ5251BLT1G, it lacks automotive qualification documentation but matches all electrical performance in non-automotive contexts.
Availability
MMBZ5251BLT1G is available at Aetrix Electronics and suitable for portable electronics, USB interface protection, and industrial sensor signal conditioning requiring stable component supply and consistent Zener voltage tolerance.
Supply support for MMBZ5251BLT1G 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, and consumer markets.
The MMBZ52xxBLT1G series was designed specifically for compact, high-density voltage regulation in battery-powered and space-constrained applications - emphasizing low profile, ESD resilience, and precise Zener voltage control.
FAQ
What is the exact Zener voltage tolerance for MMBZ5251BLT1G at 25°C?
The MMBZ5251BLT1G has a guaranteed Zener voltage range of 20.9 V (minimum) to 23.1 V (maximum) at IZT = 5.6 mA and TA = 25°C, with 22 V as the nominal value. This ±5% tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet Rev. 16 (July 2024).
Can MMBZ5251BLT1G be used in place of MMBZ5252BLT1G?
No - MMBZ5251BLT1G (22 V nominal) and MMBZ5252BLT1G (24 V nominal) are distinct voltage grades within the same family and are not interchangeable without circuit redesign. Their Zener voltages differ by 2 V, and their test currents differ (5.6 mA vs. 5.2 mA), affecting regulation accuracy and thermal behavior in the same application.
Is pin 2 of MMBZ5251BLT1G electrically connected internally?
No - pin 2 of MMBZ5251BLT1G is explicitly designated as "No Connection" in the marking diagram and mechanical outline (Style 8). It is an internal dummy lead with no electrical function and must remain unconnected on the PCB to avoid unintended coupling or thermal stress.
What is the maximum allowable continuous power dissipation for MMBZ5251BLT1G at 85°C ambient?
At TA = 85°C, MMBZ5251BLT1G's power dissipation must be derated linearly from 225 mW at 25°C using 1.8 mW/°C. The calculation yields 225 mW − (1.8 mW/°C × 60°C) = 117 mW maximum continuous power. Exceeding this risks exceeding the 150°C maximum junction temperature.
Does MMBZ5251BLT1G meet automotive qualification standards?
MMBZ5251BLT1G itself is not AEC-Q101 qualified. For automotive applications requiring formal qualification, the SZMMBZ5251BLT1G variant - identical in all electrical and mechanical specifications but manufactured under automotive-grade process controls and PPAP documentation - must be selected instead.
MMBZ5251BLT1G 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):
- 22 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 29 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 17 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
MMBZ5251BLT1G FAQ
1.How can I place an order for MMBZ5251BLT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5251BLT1G 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 MMBZ5251BLT1G reliable?
The price and inventory of MMBZ5251BLT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5251BLT1G is usually 5 days.
3.What payment methods are accepted for MMBZ5251BLT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5251BLT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5251BLT1G?
MMBZ5251BLT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5251BLT1G 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 MMBZ5251BLT1G?
For technical support, including MMBZ5251BLT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5251BLT1G requirements.
6.How does Aetrix verify that MMBZ5251BLT1G is sourced from the original manufacturer or authorized distributors?
All MMBZ5251BLT1G 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 MMBZ5251BLT1G meets industry standards.
7.What is the process for return or replacement of MMBZ5251BLT1G?
All MMBZ5251BLT1G units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5251BLT1G, 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 MMBZ5251BLT1G part is unused and in its original packaging.
Return procedure for MMBZ5251BLT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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