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onsemi MMSZ5249BT1
- Part No.:
- MMSZ5249BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5249BT1.pdf
- Description:
- DIODE ZENER 19V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:4,126
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Product details
Overview
MMSZ5249BT1 from ON Semiconductor is a 5% tolerance, 19 V nominal Zener voltage regulator diode in SOD−123 surface-mount package, rated for 500 mW power dissipation on FR−5 board at 75°C, with 6.6 mA test current (IZT), 23 Ω dynamic impedance (ZZT), and 0.1 µA reverse leakage at 14 V (VR). It serves as a precision voltage reference or overvoltage clamp in low-power analog circuits, power supply feedback loops, and ESD-protected sensor interfaces.
For engineers reviewing the MMSZ5249BT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, SOD−123 terminal mapping, real-world use cases, and validated alternative parts for voltage regulation design-in.
Technical Context
The MMSZ5249BT1 operates as a silicon planar Zener diode, relying on controlled avalanche breakdown to maintain stable reverse-biased voltage regulation. Its 19 V nominal Zener voltage is specified under thermal equilibrium conditions (TL = 30°C ±1°C), with temperature coefficient optimized for minimal drift across −55°C to +150°C operating range.
It exhibits 23 Ω dynamic impedance at 6.6 mA test current and 600 Ω maximum impedance at knee current (IZK = 0.25 mA), enabling predictable regulation performance in low-current bias networks. The device features Class 3 ESD robustness (>16 kV HBM) and Pb−free construction compliant with AEC−Q101 for automotive applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18.05–19.95 V @ IZT = 6.6 mA - defines stable regulation window for feedback or clamping |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - sets maximum continuous power handling on standard PCB |
| Zener Impedance (ZZT) | 23 Ω @ IZT - determines output voltage variation under load current changes |
| Reverse Leakage (IR) | 0.1 µA @ VR = 14 V - ensures minimal quiescent current in high-impedance bias networks |
| Thermal Resistance (RJA) | 340 °C/W - indicates junction-to-ambient heat transfer efficiency on FR−5 board |
| ESD Rating | Class 3 (>16 kV HBM) - provides robustness against electrostatic discharge during handling and assembly |
| Operating Temperature | −55°C to +150°C - supports deployment in industrial and automotive under-hood environments |
Pinout & Package
SOD−123 plastic surface-mount package with cathode indicated by polarity band; case dimensions: 2.54–2.84 mm length × 1.40–1.80 mm width × 0.94–1.35 mm height; designed for automated placement and reflow soldering per JEDEC standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener anode connection point | Connected to regulated voltage node; reverse-biased operation requires cathode at higher potential than anode |
| 2 (Anode) | Zener cathode connection point | Typically grounded or tied to lower-potential reference; completes reverse-bias path for regulation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating | Enables stable voltage reference generation in space-constrained, low-power analog stages without external heatsinking |
| ±5% Zener Tolerance | Provides cost-effective regulation accuracy suitable for non-critical biasing and protection functions |
| SOD−123 Package | Supports high-density PCB layouts and automated assembly with footprint compatibility across Zener families |
| AEC−Q101 Qualified | Validates reliability for automotive electronics including body control modules and sensor signal conditioning |
| 16 kV HBM ESD Robustness | Reduces risk of field failure in exposed I/O paths and unshielded industrial interface circuits |
Applications
| Industrial Sensor Signal Conditioning | Automotive Body Control Module Reference |
|---|---|
Use Scenario: Stabilizing bias voltage for analog front-end amplifiers in temperature or pressure sensors operating across wide ambient ranges. IC Role / Device Role / Timing Role: Zener voltage reference providing fixed 19 V rail for op-amp biasing and ADC reference scaling. Use Value: Maintains <±2% output stability over −40°C to +125°C due to low TC and thermal equilibrium specification. | Use Scenario: Clamping transient voltages on LIN bus interface lines exposed to load-dump events in vehicle door modules. IC Role / Device Role / Timing Role: Overvoltage protection element shunting surge energy above 19 V to ground during ESD or inductive switching events. Use Value: Survives >16 kV HBM discharges and handles 500 mW peak pulse power without degradation per AEC−Q101 stress testing. |
| Low-Power SMPS Feedback Network | Portable Medical Device Voltage Monitor |
Use Scenario: Setting precise output voltage in isolated flyback converters using optocoupler feedback with TL431 alternatives. IC Role / Device Role / Timing Role: Precision Zener element establishing reference threshold for error amplifier input in secondary-side regulation. Use Value: Delivers 19 V regulation with 23 Ω dynamic impedance, minimizing output ripple sensitivity to load transients. | Use Scenario: Monitoring battery pack voltage in wearable ECG monitors where ultra-low leakage preserves standby time. IC Role / Device Role / Timing Role: Low-current voltage detection node triggering shutdown when cell voltage exceeds safe threshold. Use Value: Draws only 0.1 µA at 14 V reverse bias, extending battery life in always-on monitoring circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584-C19 | 19 V ±5%, 500 mW, SOD-323 package, 30 Ω ZZT @ 5 mA | Smaller footprint but higher dynamic impedance and lower surge rating | Preferred where board area is constrained and thermal margin allows reduced power derating |
| 1N4746A | 18 V ±5%, 1 W, DO-41 through-hole, 20 Ω ZZT @ 12.5 mA | Higher power rating but incompatible with SMT assembly and larger PCB footprint | Selected when legacy through-hole design or higher continuous power dissipation is required |
Compared with MMSZ5249BT1, BZX584-C19 offers space savings at the cost of higher impedance and lower surge capability, while 1N4746A provides greater power headroom but eliminates SMT compatibility-making MMSZ5249BT1 optimal for modern high-density, automotive-grade SMT designs requiring 19 V regulation.
Availability
MMSZ5249BT1 is available at Aetrix Electronics and suitable for industrial sensor conditioning, automotive body control modules, and low-power SMPS feedback networks requiring stable component supply, AEC−Q101 compliance, and Pb−free manufacturing support.
Supply support for MMSZ5249BT1 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
ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and consumer markets.
The MMSZ52xxxT1G series is part of ON Semiconductor's general-purpose Zener diode portfolio, engineered for reliable voltage regulation and transient suppression in compact, high-volume surface-mount applications.
FAQ
What is the nominal Zener voltage and tolerance of the MMSZ5249BT1?
The MMSZ5249BT1 has a nominal Zener voltage of 19 V with a ±5% tolerance, meaning its actual regulation voltage falls between 18.05 V and 19.95 V when measured at 6.6 mA test current (IZT) under thermal equilibrium conditions (TL = 30°C ±1°C). This tolerance band is confirmed in the official ON Semiconductor datasheet revision 15, page 3, and applies specifically to the "B" suffix variant in the MMSZ52xxxT1G series.
What is the maximum power dissipation rating for MMSZ5249BT1 and how does it derate with temperature?
The MMSZ5249BT1 is rated for 500 mW total power dissipation on FR−5 board at TL = 75°C, with linear derating of 6.7 mW/°C above that temperature. Its thermal resistance junction-to-ambient (RJA) is 340 °C/W, meaning junction temperature rises significantly with ambient increase-requiring careful layout and thermal relief if operating near maximum ratings. This derating behavior is defined in the Maximum Ratings table on page 2 of the ON Semiconductor datasheet.
Does MMSZ5249BT1 meet automotive qualification standards?
Yes, the MMSZ5249BT1 is AEC−Q101 qualified and PPAP capable, as explicitly stated in the Features section of the ON Semiconductor datasheet. Devices marked with the "SZ" prefix (e.g., SZMMSZ5249BT1G) are designated for automotive applications, but the base MMSZ5249BT1 shares the same die, process, and qualification-making it suitable for automotive body electronics, infotainment power rails, and sensor interfaces requiring certified reliability.
What is the reverse leakage current specification for MMSZ5249BT1 and at what voltage is it measured?
The MMSZ5249BT1 specifies a maximum reverse leakage current (IR) of 0.1 µA at VR = 14 V, as listed in the Electrical Characteristics table on page 3 of the ON Semiconductor datasheet. This low leakage enables use in high-impedance bias networks and battery-powered monitoring circuits where quiescent current must be minimized-distinct from higher-leakage variants like the 1N4746A, which exhibits ~10 µA at similar reverse voltage.
How is the pinout configured for MMSZ5249BT1 in the SOD−123 package?
The MMSZ5249BT1 uses the standard SOD−123 two-terminal configuration: Pin 1 is the cathode (marked by a polarity band), and Pin 2 is the anode. In circuit operation, the cathode must be held at a higher potential than the anode to achieve reverse-biased Zener conduction. This pinout is confirmed in the Mechanical Characteristics diagram on page 2 and the Marking Diagram on page 1 of the ON Semiconductor datasheet.
MMSZ5249BT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 19 V
- Tolerance:
- ±5%
- Power - Max:
- 500 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:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
MMSZ5249BT1 FAQ
1.How can I place an order for MMSZ5249BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5249BT1 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 MMSZ5249BT1 reliable?
The price and inventory of MMSZ5249BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5249BT1 is usually 5 days.
3.What payment methods are accepted for MMSZ5249BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5249BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5249BT1?
MMSZ5249BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5249BT1 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 MMSZ5249BT1?
For technical support, including MMSZ5249BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5249BT1 requirements.
6.How does Aetrix verify that MMSZ5249BT1 is sourced from the original manufacturer or authorized distributors?
All MMSZ5249BT1 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 MMSZ5249BT1 meets industry standards.
7.What is the process for return or replacement of MMSZ5249BT1?
All MMSZ5249BT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5249BT1, 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 MMSZ5249BT1 part is unused and in its original packaging.
Return procedure for MMSZ5249BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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