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onsemi MMBZ5249BLT1
- Part No.:
- MMBZ5249BLT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
MMBZ5249BLT1.pdf
- Description:
- DIODE ZENER 19V 225MW SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:5,730
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Product details
Overview
MMBZ5249BLT1 from onsemi is a 19 V, 225 mW surface-mount Zener diode in SOT-23 package, designed for precision voltage regulation and overvoltage protection in space-constrained circuits. It delivers 6.6 mA test current, 23 Ω dynamic impedance at IZT, and 0.1 μA reverse leakage at 14 V, supporting use in portable power rails and signal-level clamping.
For engineers reviewing the MMBZ5249BLT1 datasheet, pinout, applications, or equivalent options, key selection criteria include nominal Zener voltage tolerance (±5%), thermal resistance (556 °C/W on FR-5), ESD rating (>16 kV HBM), and SOT-23 footprint compatibility with automated assembly.
Technical Context
This device operates as a two-terminal, cathode-anode biased voltage reference with no internal connections to pin 2 (NC). Its Zener breakdown mechanism provides stable regulation across −65°C to +150°C junction temperature range, with temperature coefficient near zero at ~19 V (confirmed by Figure 1).
Electrical behavior is defined under pulsed test conditions (IZT = 6.6 mA, TA = 25°C); forward voltage remains ≤0.95 V at 10 mA. The SOT-23 package supports reflow soldering up to 260°C for 10 seconds and meets UL 94 V-0 flammability rating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18.05–19.95 V @ IZT = 6.6 mA - tight ±5% tolerance enables accurate 19 V rail clamping without external trimming. |
| Power Dissipation | 225 mW on FR-5 board - limits continuous dissipation in handheld PCBs; derates 1.8 mW/°C above 25°C. |
| Zener Impedance (ZZT) | 23 Ω @ IZT - low dynamic impedance ensures minimal output voltage shift under load transients. |
| Reverse Leakage (IR) | 0.1 μA @ VR = 14 V - negligible standby current preserves battery life in always-on sensor nodes. |
| ESD Rating | Class 3 (>16 kV HBM) - protects downstream circuitry from human-body model discharge events during handling or operation. |
| Package | SOT-23 (TO-236), 2.90 × 1.30 × 1.00 mm - industry-standard footprint compatible with high-density routing and pick-and-place assembly. |
| Junction Temp Range | −65°C to +150°C - supports operation in automotive under-hood and industrial control environments. |
Pinout & Package
SOT-23 plastic surface-mount package with void-free thermosetting case, corrosion-resistant finish, and cathode indicated by polarity band. Maximum soldering temperature: 260°C for 10 seconds. Flammability rating: UL 94 V-0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode | Connected to lower-potential node; reverse-biased during Zener operation; carries forward current when used as rectifier. |
| 2 | No Connection | Internally unconnected; must remain floating-no PCB trace or pad should tie to this terminal. |
| 3 | Cathode | Connected to higher-potential node; defines regulated output voltage reference point; marked by polarity band on package. |
Key Features
| Feature | Design Value |
|---|---|
| 225 mW Power Rating | Enables compact voltage clamping in battery-powered devices without heatsinking or layout derating. |
| Pb-Free, Halogen-Free/BFR-Free | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-609A Class 3 moisture sensitivity level (MSL3). |
| Optimized SOT-23 Footprint | Reduces board area by >70% vs. DO-35; supports 0.65 mm pitch placement and AOI-compatible marking. |
| High ESD Robustness | Withstands >16 kV contact discharge per ANSI/ESDA/JEDEC JS-001, eliminating need for external TVS in many I/O paths. |
| Wide Zener Range Coverage | Part of MMBZ52xxBLT1G family spanning 2.4–91 V, enabling single-supplier sourcing across multiple voltage rails. |
Applications
| Portable Power Rail Protection | Signal-Level Voltage Clamping |
|---|---|
|
Use Scenario: Protecting 3.3 V or 5 V logic inputs in Bluetooth headsets and smart wearables from ESD and transient overvoltage. IC Role / Device Role / Timing Role: Two-terminal shunt regulator acting as low-leakage clamp between signal line and ground. Use Value: 0.1 μA leakage at 14 V prevents measurable loading on high-impedance sensor outputs or GPIO lines. |
Use Scenario: Stabilizing reference voltage for ADC biasing in medical patch monitors with single-cell Li-ion supply. IC Role / Device Role / Timing Role: Precision Zener element providing temperature-stable 19 V reference for analog front-end scaling. Use Value: Near-zero TC at 19 V (per Figure 1) minimizes drift-induced measurement error across −20°C to +70°C operating range. |
| Automotive Body Control Module | Industrial Sensor Interface |
|
Use Scenario: Overvoltage suppression on LIN bus transceiver power pins in door module ECUs exposed to load dump pulses. IC Role / Device Role / Timing Role: Fast-response shunt limiter absorbing short-duration transients while maintaining system reset integrity. Use Value: 225 mW rating allows safe dissipation of 100 ms, 24 V/100 mA surge without thermal runaway or parameter shift. |
Use Scenario: Providing regulated excitation voltage for 4–20 mA loop-powered pressure transmitters in factory automation systems. IC Role / Device Role / Timing Role: Stable Zener source referenced to isolated ground, enabling precise current loop compliance. Use Value: 23 Ω ZZT ensures <10 mV output variation under 1 mA load changes-critical for 0.1% accuracy loops. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBZ5249BLT1G | Pb-free version with identical electrical specs and SOT-23 package; differs only in RoHS-compliant plating and microdot marking. | Required for new designs targeting EU/China RoHS compliance; same thermal and electrical performance as MMBZ5249BLT1. | Select MMBZ5249BLT1G for production builds requiring full halogen-free certification and PPAP documentation. |
| BZX84-C18LT1G | 18 V nominal Zener (±5%), 350 mW rating, 20 Ω ZZT @ 5 mA - higher power but wider VZ tolerance and different test current. | Better suited for higher-current clamping; less precise for 19 V reference due to 18 V nominal and looser tempco curve. | Choose BZX84-C18LT1G only if 18 V regulation suffices and board layout accommodates its slightly larger thermal footprint. |
Compared with MMBZ5249BLT1, the MMBZ5249BLT1G offers identical regulation performance with certified Pb-free construction, while BZX84-C18LT1G trades tighter 19 V accuracy for higher power margin and broader availability-but requires validation of 18 V vs. 19 V system tolerance stack-up.
Availability
MMBZ5249BLT1 is available at Aetrix Electronics and suitable for portable electronics, automotive body control modules, and industrial sensor interfaces requiring stable component supply, consistent parametric performance, and long-term obsolescence management.
Supply support for MMBZ5249BLT1 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 focused on energy-efficient electronics, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.
The MMBZ52xxBLT1G series was engineered for ultra-compact, high-reliability voltage regulation in portable and automotive systems-prioritizing low leakage, high ESD immunity, and SMT manufacturability over legacy through-hole alternatives.
FAQ
What is the Zener voltage tolerance of MMBZ5249BLT1?
The MMBZ5249BLT1 has a specified Zener voltage range of 18.05 V to 19.95 V at IZT = 6.6 mA and TA = 25°C, representing a ±5% tolerance around the nominal 19 V value. This tolerance is guaranteed per onsemi's Electrical Characteristics table and applies to all units within specification limits.
Does MMBZ5249BLT1 have a connection on pin 2?
No, MMBZ5249BLT1 uses Style 8 pinout per onsemi's mechanical outline: pin 1 is anode, pin 2 is no connection (NC), and pin 3 is cathode. Pin 2 must remain unconnected on the PCB-no trace, via, or copper pour should attach to it.
What is the maximum power dissipation for MMBZ5249BLT1 on standard FR-5 PCB?
MMBZ5249BLT1 is rated for 225 mW total power dissipation on FR-5 board at 25°C ambient, with linear derating of 1.8 mW/°C above that temperature. This limit assumes standard 1 oz copper, no thermal vias, and typical JEDEC 51-2 board layout conditions.
Is MMBZ5249BLT1 suitable for automotive applications?
MMBZ5249BLT1 is not AEC-Q101 qualified; for automotive use, select the SZMMBZ5249BLT1G variant instead. That part shares identical electrical specs but adds automotive-grade process controls, PPAP capability, and site-specific change management required for Tier 1 supply chains.
How does the temperature coefficient of MMBZ5249BLT1 affect regulation stability?
Per onsemi's Figure 1, the MMBZ5249BLT1 (19 V nominal) exhibits a temperature coefficient near 0 mV/°C, meaning its Zener voltage remains highly stable across −55°C to +150°C. This minimizes drift in precision reference or clamping applications where thermal gradients are present.
MMBZ5249BLT1 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):
- 19 V
- Tolerance:
- ±5%
- Power - Max:
- 225 mW
- Impedance (Max) (Zzt):
- 23 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 14 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
MMBZ5249BLT1 FAQ
1.How can I place an order for MMBZ5249BLT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMBZ5249BLT1 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 MMBZ5249BLT1 reliable?
The price and inventory of MMBZ5249BLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBZ5249BLT1 is usually 5 days.
3.What payment methods are accepted for MMBZ5249BLT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBZ5249BLT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMBZ5249BLT1?
MMBZ5249BLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMBZ5249BLT1 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 MMBZ5249BLT1?
For technical support, including MMBZ5249BLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBZ5249BLT1 requirements.
6.How does Aetrix verify that MMBZ5249BLT1 is sourced from the original manufacturer or authorized distributors?
All MMBZ5249BLT1 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 MMBZ5249BLT1 meets industry standards.
7.What is the process for return or replacement of MMBZ5249BLT1?
All MMBZ5249BLT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMBZ5249BLT1, 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 MMBZ5249BLT1 part is unused and in its original packaging.
Return procedure for MMBZ5249BLT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMBZ5249BLT1 Tags
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