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onsemi MMBZ5259BLT1
- Part No.:
- MMBZ5259BLT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5259BLT1.pdf
- Description:
- DIODE ZENER 39V 225MW SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,433
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Product details
Overview
MMBZ5259BLT1 from onsemi is a 39 V ±5% Zener diode in SOT-23 package, rated for 225 mW power dissipation on FR-5 board, with 80 Ω dynamic impedance at 3.2 mA test current and 0.1 μA leakage at 30 V reverse bias. It provides precision voltage regulation in space-constrained portable electronics such as smartphone power rails and USB interface protection circuits.
For engineers reviewing the MMBZ5259BLT1 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 cases aligned to its 37.05–40.95 V Zener range and SOT-23 mechanical footprint.
Technical Context
This Zener diode operates in reverse breakdown mode with a nominal Zener voltage of 39 V at 3.2 mA test current (IZT), exhibiting a temperature coefficient near +0.075 %/°C in this voltage range. Its 800 Ω maximum impedance at knee current (IZK = 0.25 mA) ensures stable regulation under light-load conditions.
The device uses a planar epitaxial construction with cathode-indicated polarity band, optimized for automated placement on high-density PCBs. Thermal resistance is 556 °C/W junction-to-ambient on FR-5 board, requiring derating by 1.8 mW/°C above 25 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05–40.95 V at IZT = 3.2 mA - defines regulated output voltage tolerance window for reference or clamp applications. |
| Power Dissipation (PD) | 225 mW on FR-5 board at 25 °C - sets maximum continuous power handling before thermal derating applies. |
| Zener Impedance (ZZT) | 80 Ω max at IZT = 3.2 mA - indicates low AC impedance for stable voltage under dynamic load changes. |
| Leakage Current (IR) | 0.1 μA max at VR = 30 V - ensures minimal standby current draw in battery-powered systems. |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - enables direct integration into handheld device I/O lines without external ESD protection. |
| Junction Temperature Range | −65 °C to +150 °C - supports operation in automotive under-hood and industrial environments. |
Pinout & Package
SOT-23 (TO-236) surface-mount package, 2.90 × 1.30 × 1.00 mm, void-free thermosetting plastic case with corrosion-resistant finish. Cathode indicated by polarity band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node in reverse-bias configuration; forms input side of voltage clamp. |
| 2 | No Connection | Internally unconnected terminal; must remain floating-no PCB trace or pad required. |
| 3 | Cathode | Connected to higher-potential node; serves as regulated output or clamping reference point. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-Free, Halogen-Free/BFR-Free | RoHS-compliant construction enabling compliance with global environmental regulations and reflow compatibility. |
| Small SOT-23 Footprint | Enables placement in <1.5 mm² board area-critical for multi-rail voltage supervision in smartphones and wearables. |
| 225 mW Power Rating | Supports transient overvoltage clamping in 3.3 V–5 V logic interfaces without external heat sinking. |
| High ESD Robustness | Withstands >16 kV HBM strikes, reducing need for discrete TVS devices in USB, SIM, and SD card signal paths. |
Applications
| USB Interface Protection | Smartphone Power Rail Clamp |
|---|---|
Use Scenario: Protecting USB 2.0 D+ and D− lines from ESD events and supply rail coupling transients. IC Role / Device Role: Zener-based bidirectional clamp referenced to ground or VBUS. Use Value: Leverages 39 V standoff and Class 3 ESD rating to absorb 8 kV contact discharges without degradation. |
Use Scenario: Clamping 5 V or 3.3 V system rails during hot-swap or load-dump events in mobile PMIC domains. IC Role / Device Role: Standalone shunt regulator providing overvoltage protection for LDO inputs. Use Value: 80 Ω ZZT ensures fast response to 100 ns transients while maintaining <100 mV overshoot. |
| IoT Sensor Node Reference | Industrial PLC Input Conditioning |
Use Scenario: Providing stable 39 V reference for ADC biasing or op-amp level-shifting in battery-powered sensors. IC Role / Device Role: Precision Zener voltage source with low tempco and tight tolerance. Use Value: 5% VZ tolerance and −65 °C to +150 °C operating range enable reliable calibration across environmental extremes. |
Use Scenario: Conditioning 24 V DC input signals in programmable logic controller analog input modules. IC Role / Device Role: Overvoltage limiter protecting downstream op-amps and ADC front-ends. Use Value: 225 mW rating allows sustained clamping of 30 V transients without thermal runaway in sealed enclosures. |
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-C39LT1G | Same 39 V nominal Zener, but 300 mW rating on FR-4 and 100 Ω ZZT at 5 mA - higher power, slightly higher impedance. | Preferred where higher surge energy absorption is needed, e.g., industrial fieldbus nodes with frequent transients. | Select BZX84-C39LT1G when board layout permits larger thermal relief or when 300 mW headroom improves long-term reliability. |
| MMBZ5259BS | Identical electrical specs but in SOD-123 package - 3.7 × 1.6 × 1.1 mm, higher thermal mass, no NC pin. | Better suited for manual repair or high-reliability aerospace assemblies where SOT-23 pick-and-place yield is marginal. | Choose MMBZ5259BS when solder joint integrity under thermal cycling is prioritized over board area minimization. |
Compared with MMBZ5259BLT1, BZX84-C39LT1G offers higher power margin but requires more board area and has looser regulation at light loads; MMBZ5259BS trades miniaturization for improved thermal stability and eliminates NC-pin routing complexity.
Availability
MMBZ5259BLT1 is available at Aetrix Electronics and suitable for smartphone power management, USB interface protection, and industrial sensor signal conditioning requiring stable component supply and full RoHS compliance.
Supply support for MMBZ5259BLT1 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 is a global semiconductor supplier specializing in energy-efficient electronics, with leadership in automotive, industrial, cloud, and IoT solutions.
The MMBZ52xxBLT1G series was designed for compact, high-density voltage regulation in portable and battery-powered systems-emphasizing low profile, ESD resilience, and consistent Zener performance across temperature.
FAQ
What is the Zener voltage tolerance of MMBZ5259BLT1?
The MMBZ5259BLT1 has a Zener voltage range of 37.05 V to 40.95 V at IZT = 3.2 mA, corresponding to a ±5% tolerance around the nominal 39 V rating. This tolerance is guaranteed across the full operating temperature range of −65 °C to +150 °C and is measured using pulse testing to avoid self-heating effects. The MMBZ5259BLT1 datasheet specifies this range in the Electrical Characteristics table on page 3.
Does MMBZ5259BLT1 have a pin 2 connection?
No, pin 2 of the MMBZ5259BLT1 is internally not connected (NC). As confirmed in the marking diagram and mechanical outline on page 6 of the onsemi datasheet, only pins 1 (anode) and 3 (cathode) are functional. Pin 2 must remain unconnected on the PCB-no trace, pad, or via should be routed to it, as doing so may compromise device reliability or cause assembly defects.
What is the maximum allowable ambient temperature before derating MMBZ5259BLT1?
The MMBZ5259BLT1 must be derated above 25 °C ambient temperature at 1.8 mW/°C when mounted on FR-5 board. At 85 °C ambient, its usable power drops to 225 mW − (85 − 25) × 1.8 = 117 mW. This derating is defined in the Maximum Ratings table on page 1 of the datasheet and assumes standard JEDEC 2-layer board conditions. For alumina substrates, derating is 2.4 mW/°C starting at 25 °C.
Is MMBZ5259BLT1 suitable for automotive applications?
The standard MMBZ5259BLT1 is not AEC-Q101 qualified. However, the SZMMBZ5259BLT1G variant-identical electrically but with automotive-grade process controls, PPAP documentation, and extended traceability-is qualified per AEC-Q101. Engineers requiring automotive use must specify the SZ-prefix part; the MMBZ5259BLT1 itself is intended for commercial and industrial applications only.
What is the forward voltage drop of MMBZ5259BLT1 at 10 mA?
The MMBZ5259BLT1 exhibits a maximum forward voltage (VF) of 0.95 V at IF = 10 mA, as specified in the Electrical Characteristics table on page 2 of the datasheet. This value is typical for silicon Zener diodes in SOT-23 packages and confirms proper anode-cathode conduction behavior during forward bias testing or dual-purpose clamp configurations.
MMBZ5259BLT1 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):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 80 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 30 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)
MMBZ5259BLT1 FAQ
1.How can I place an order for MMBZ5259BLT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5259BLT1 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 MMBZ5259BLT1 reliable?
The price and inventory of MMBZ5259BLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5259BLT1 is usually 5 days.
3.What payment methods are accepted for MMBZ5259BLT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5259BLT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5259BLT1?
MMBZ5259BLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5259BLT1 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 MMBZ5259BLT1?
For technical support, including MMBZ5259BLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5259BLT1 requirements.
6.How does Aetrix verify that MMBZ5259BLT1 is sourced from the original manufacturer or authorized distributors?
All MMBZ5259BLT1 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 MMBZ5259BLT1 meets industry standards.
7.What is the process for return or replacement of MMBZ5259BLT1?
All MMBZ5259BLT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5259BLT1, 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 MMBZ5259BLT1 part is unused and in its original packaging.
Return procedure for MMBZ5259BLT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5259BLT1 Tags
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