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onsemi SZMMSZ5249BT1G
- Part No.:
- SZMMSZ5249BT1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
SZMMSZ5249BT1G.pdf
- Description:
- DIODE ZENER 19V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:5,426
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Product details
Overview
SZMMSZ5249BT1G from onsemi is a 19 V ±5% Zener diode in SOD−123 package, rated for 500 mW power dissipation at TL = 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, DC-DC feedback loops, and automotive sensor signal conditioning.
For engineers reviewing the SZMMSZ5249BT1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal equilibrium performance, junction-to-lead thermal resistance (150 °C/W), ESD robustness (>16 kV HBM), and AEC−Q101 qualification for automotive use.
Technical Context
This device operates as a two-terminal voltage regulator diode, maintaining stable reverse breakdown at nominal 19 V under thermal equilibrium conditions (TL = 30°C ±1°C). Its Zener impedance of 23 Ω at 6.6 mA IZT ensures low AC voltage variation during regulation, while its 150 °C/W junction-to-lead thermal resistance supports reliable heat transfer to PCB copper.
The SZMMSZ5249BT1G features a cathode band marking, Pb-free construction, UL 94 V−0 flammability rating, and is qualified to AEC−Q101 for automotive applications. Its 0.1 μA leakage at 14 V enables low-power standby operation, and its 1700 Ω impedance at knee current (IZK = 0.25 mA) defines low-current regulation capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18.05–19.95 V @ IZT = 6.6 mA - defines tight 5% tolerance band for stable reference accuracy |
| Power Dissipation (PD) | 500 mW on FR−5 board @ TL = 75°C - sets maximum continuous operating power before thermal derating |
| Zener Impedance (ZZT) | 23 Ω @ IZT = 6.6 mA - determines AC output ripple suppression capability in regulated supplies |
| Reverse Leakage (IR) | 0.1 μA @ VR = 14 V - ensures minimal quiescent current draw in battery-powered circuits |
| Junction Temp Range | −55°C to +150°C - supports operation in under-hood automotive and industrial environments |
| ESD Rating | Class 3 (>16 kV HBM) - provides robust handling without external protection in assembly and field use |
| Thermal Resistance (RJL) | 150 °C/W - enables predictable junction temperature rise when mounted on standard PCB copper |
Pinout & Package
SOD−123 surface-mount plastic package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant, solderable finish; cathode indicated by polarity band; UL 94 V−0 rated.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Reverse-biased Zener terminal | Connected to regulated voltage node; carries full Zener current during breakdown |
| 2 (Anode) | Reference/ground terminal | Bias reference point; must be connected to lowest potential in regulation path |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 qualification | Validated for automotive electronics including engine control modules and body controllers |
| 500 mW FR−5 board rating | Enables direct integration into space-constrained PCBs without heatsinking |
| ±5% Zener tolerance | Meets cost-sensitive precision reference requirements without trimming circuitry |
| 16 kV HBM ESD rating | Eliminates need for external ESD protection in most consumer and industrial interfaces |
| Pb-free and RoHS compliant | Supports global environmental compliance without solderability or reliability trade-offs |
Applications
| Automotive Sensor Signal Conditioning | Industrial Analog Input Protection |
|---|---|
Use Scenario: Stabilizing bias voltage for Hall-effect position sensors in transmission control units. IC Role / Device Role / Timing Role: Zener reference providing fixed 19 V rail for sensor excitation and ADC reference scaling. Use Value: Maintains ±0.95 V regulation window across −40°C to +125°C ambient, ensuring consistent sensor output linearity. |
Use Scenario: Clamping transient overvoltage on 16-bit analog input channels in PLC I/O modules. IC Role / Device Role / Timing Role: Fast-response shunt protector limiting input to ≤20 V during surge events. Use Value: 23 Ω ZZT minimizes clamping overshoot; 0.1 μA IR avoids loading high-impedance signal sources. |
| DC-DC Feedback Reference | Low-Power Microcontroller Reset Circuit |
Use Scenario: Setting output voltage of isolated flyback converter in medical power supply. IC Role / Device Role / Timing Role: Precision Zener in optocoupler feedback loop to regulate secondary-side output. Use Value: 5% tolerance and thermal equilibrium specification ensure <±1.5% output drift over temperature and load. |
Use Scenario: Generating clean reset threshold for ARM Cortex-M0+ microcontrollers in smart meters. IC Role / Device Role / Timing Role: Voltage monitor establishing 19 V brown-out detection level. Use Value: AEC−Q101 qualification and −55°C to +150°C range guarantee reliability in outdoor metering 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 |
|---|---|---|---|
| MMSZ5249BT1G | Same electrical specs but lacks AEC−Q101 qualification and SZ-prefix automotive traceability | Approved for commercial/industrial use only; not suitable for automotive PPAP programs | Select when automotive qualification is unnecessary and cost sensitivity is higher |
| BZX84-C18LT1G | 18 V nominal, ±5%, 350 mW rating, SOT-23 package, 40 Ω ZZT @ 5 mA | Lower power and higher impedance limit use in precision references or high-current clamping | Choose for legacy SOT-23 footprint compatibility where 19 V exactness and 500 mW headroom are not required |
Compared with MMSZ5249BT1G and BZX84-C18LT1G, the SZMMSZ5249BT1G uniquely combines automotive qualification, 500 mW power handling, and 23 Ω low-impedance regulation-making it the only option for AEC−Q101-compliant 19 V reference designs requiring thermal stability and high surge immunity.
Availability
SZMMSZ5249BT1G is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLC analog inputs, and medical DC-DC converters requiring stable component supply, long-term lifecycle assurance, and AEC−Q101 traceability.
Supply support for SZMMSZ5249BT1G 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 (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The SZMMSZ52xxxT1G series is designed specifically for automotive-grade voltage regulation and transient suppression, with emphasis on thermal equilibrium performance, AEC−Q101 reliability, and high-density SOD−123 packaging.
FAQ
What is the Zener voltage tolerance of SZMMSZ5249BT1G?
The SZMMSZ5249BT1G has a ±5% Zener voltage tolerance, meaning its reverse breakdown voltage is guaranteed between 18.05 V and 19.95 V when measured at IZT = 6.6 mA and device junction in thermal equilibrium (TL = 30°C ±1°C). This tolerance is specified per onsemi's MMSZ52xxxT1G Series datasheet Rev. 17, page 3.
Is SZMMSZ5249BT1G qualified for automotive applications?
Yes, SZMMSZ5249BT1G is AEC−Q101 qualified and PPAP capable, with the "SZ" prefix indicating compliance for automotive and other applications requiring unique site and control change requirements. Its qualification covers temperature cycling, humidity testing, and mechanical shock per AEC standards, as documented in the official onsemi datasheet.
What is the maximum power dissipation for SZMMSZ5249BT1G on a standard PCB?
SZMMSZ5249BT1G is rated for 500 mW total power dissipation on an FR−5 board at lead temperature (TL) of 75°C. Above 75°C, it derates linearly at 6.7 mW/°C. This rating assumes use of the minimum recommended footprint and accounts for thermal conduction through leads to PCB copper, per datasheet Maximum Ratings table.
How does the thermal resistance of SZMMSZ5249BT1G affect its operating temperature?
SZMMSZ5249BT1G has a junction-to-lead thermal resistance (RJL) of 150 °C/W, meaning each watt of dissipated power raises the junction temperature 150°C above the lead temperature. For example, at 300 mW dissipation and TL = 75°C, junction temperature reaches ~120°C - well within its −55°C to +150°C operating range.
What is the reverse leakage current specification for SZMMSZ5249BT1G?
The reverse leakage current (IR) for SZMMSZ5249BT1G is specified as 0.1 μA maximum at VR = 14 V and TA = 25°C. This low leakage supports ultra-low-power applications such as battery-backed sensor nodes and always-on reset circuits where standby current must remain below 1 μA.
SZMMSZ5249BT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SZMMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
SZMMSZ5249BT1G FAQ
1.How can I place an order for SZMMSZ5249BT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMSZ5249BT1G 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 SZMMSZ5249BT1G reliable?
The price and inventory of SZMMSZ5249BT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ5249BT1G is usually 5 days.
3.What payment methods are accepted for SZMMSZ5249BT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ5249BT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMSZ5249BT1G?
SZMMSZ5249BT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMSZ5249BT1G 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 SZMMSZ5249BT1G?
For technical support, including SZMMSZ5249BT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ5249BT1G requirements.
6.How does Aetrix verify that SZMMSZ5249BT1G is sourced from the original manufacturer or authorized distributors?
All SZMMSZ5249BT1G 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 SZMMSZ5249BT1G meets industry standards.
7.What is the process for return or replacement of SZMMSZ5249BT1G?
All SZMMSZ5249BT1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ5249BT1G, 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 SZMMSZ5249BT1G part is unused and in its original packaging.
Return procedure for SZMMSZ5249BT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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