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onsemi SZMMSZ5259BT1
- Part No.:
- SZMMSZ5259BT1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
SZMMSZ5259BT1.pdf
- Description:
- DIODE ZENER 39V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:30,625
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Product details
Overview
SZMMSZ5259BT1 from onsemi is a 39 V ±5% Zener voltage regulator diode in SOD−123 surface-mount package, rated for 500 mW power dissipation at TL = 75°C, with 80 Ω dynamic impedance at 3.2 mA test current and 0.1 µA leakage at 30 V reverse bias - used for precision voltage reference and overvoltage protection in automotive power management circuits.
For engineers reviewing the SZMMSZ5259BT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, cathode/anode terminal roles, AEC−Q101 qualification status, and direct alternatives for voltage reference design in constrained PCB layouts.
Technical Context
This device operates as a two-terminal silicon Zener diode with stable reverse breakdown at nominal 39 V under thermal equilibrium (TL = 30°C ±1°C), specified with 5% tolerance and characterized at IZT = 3.2 mA. Its junction-to-ambient thermal resistance is 340°C/W, enabling predictable power derating above 75°C ambient.
The SOD−123 package features a void-free thermosetting plastic case, UL 94 V−0 flammability rating, and Pb−free construction compliant with AEC−Q101. Cathode polarity is marked by a band, and maximum soldering temperature is 260°C for 10 seconds.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05–40.95 V @ IZT = 3.2 mA - defines stable regulation point for feedback loops and clamp thresholds |
| Power Dissipation (PD) | 500 mW @ TL = 75°C - sets maximum continuous DC power before thermal derating begins |
| Zener Impedance (ZZT) | 80 Ω @ IZT = 3.2 mA - determines output voltage variation under load transients |
| Leakage Current (IR) | 0.1 µA @ VR = 30 V - ensures minimal standby current in high-impedance bias networks |
| Junction Temperature Range | −55°C to +150°C - supports operation in under-hood automotive environments |
| ESD Rating | Class 3 (>16 kV HBM) - provides robustness against handling and board-level ESD events |
| Package | SOD−123 (Case 425) - enables automated placement and fits 2.54 mm pitch footprints with 1.4–1.8 mm width |
Pinout & Package
SOD−123 surface-mount package with molded plastic body, cathode indicated by a band on terminal 1. Dimensions: 2.54–2.84 mm length × 1.40–1.80 mm width × 0.94–1.35 mm height. Compatible with standard reflow profiles per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated voltage node; reverse-biased during Zener operation |
| 2 (Non-banded End) | Anode | Connected to ground or lower-potential rail; completes conduction path during breakdown |
Key Features
| Feature | Design Value |
|---|---|
| AEC−Q101 Qualified | Validated for automotive applications including engine control units and body electronics |
| Thermal Equilibrium Spec | Zener voltage measured at TL = 30°C ±1°C - ensures repeatable calibration across production lots |
| Pb−Free Construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 |
| High ESD Robustness | 16 kV Human Body Model rating - eliminates need for external ESD protection in many signal-path designs |
| Optimized for Automated Assembly | Flat, coplanar terminals and standardized tape-and-reel packaging support high-speed pick-and-place |
Applications
| Automotive Engine Control Unit (ECU) | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Stabilizing reference voltage for analog-to-digital converter inputs in engine knock sensor interface circuits. IC Role / Device Role / Timing Role: Precision voltage reference providing 39 V bias for op-amp gain-setting networks. Use Value: Maintains ADC accuracy across −40°C to +125°C ambient with <±0.5% drift due to low TC and AEC−Q101 validation. |
Use Scenario: Clamping transient overvoltage on 24 V industrial fieldbus lines exposed to inductive switching noise. IC Role / Device Role / Timing Role: Two-terminal shunt protector absorbing surge energy without active control. Use Value: Limits line voltage to ≤41 V peak with 80 Ω ZZT, preventing damage to downstream RS-485 transceivers. |
| Medical Power Supply Feedback | Consumer Audio DC Rail Monitoring |
Use Scenario: Providing isolated feedback reference for secondary-side regulation in Class II medical AC/DC adapters. IC Role / Device Role / Timing Role: Zener-based voltage divider element in optocoupler-coupled feedback loop. Use Value: Enables <1% output regulation tolerance while meeting IEC 60601 creepage requirements via compact SOD−123 footprint. |
Use Scenario: Detecting undervoltage conditions on 36 V amplifier rails in battery-powered portable speakers. IC Role / Device Role / Timing Role: Threshold detector triggering microcontroller reset when rail drops below 37.05 V. Use Value: Leverages tight 5% VZ tolerance and 0.1 µA IR to minimize quiescent current in always-on monitoring circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMSZ5259BT1G | Same electrical specs and SOD−123 package; differs only in marking (C1 vs M4) and Pb−free compliance documentation | No functional difference; accepted in non-automotive industrial designs lacking AEC−Q101 requirement | Select when AEC−Q101 is not mandated and cost optimization is prioritized |
| BZX84-C39 | 39 V ±5%, but rated at 300 mW and uses SOT−23 package - higher thermal resistance (450°C/W) and larger footprint | Lower power handling limits use in high-current clamp applications; requires layout revision for SOT−23 pad geometry | Choose only if existing SOT−23 footprint must be reused and 300 mW suffices |
Compared with MMSZ5259BT1G, SZMMSZ5259BT1 offers identical regulation performance with added AEC−Q101 validation and PPAP capability; versus BZX84-C39, it delivers 67% higher power rating and 24% lower thermal resistance in a smaller SOD−123 outline - critical for space-constrained automotive modules.
Availability
SZMMSZ5259BT1 is available at Aetrix Electronics and suitable for automotive engine control units, industrial sensor interfaces, and medical power supply feedback circuits requiring stable component supply, long-term lifecycle continuity, and AEC−Q101-compliant sourcing.
Supply support for SZMMSZ5259BT1 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 delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.
SZMMSZ5259BT1 belongs to the MMSZ52xxxT1G/SZMMSZ52xxxT1G family of Zener regulators engineered for high-reliability voltage reference and overvoltage protection in space-constrained, thermally demanding environments.
FAQ
What is the Zener voltage tolerance and test condition for SZMMSZ5259BT1?
The SZMMSZ5259BT1 has a ±5% Zener voltage tolerance, with nominal 39 V specified at IZT = 3.2 mA and device junction in thermal equilibrium at TL = 30°C ±1°C. This ensures consistent regulation across production batches and aligns with automotive-grade calibration standards required for the SZ prefix variant.
Is SZMMSZ5259BT1 suitable for automotive applications?
Yes, SZMMSZ5259BT1 is AEC−Q101 qualified and PPAP capable, with the "SZ" prefix indicating automotive-specific site controls and change management. It operates across −55°C to +150°C junction temperature and meets stringent ESD (Class 3 HBM) and thermal cycling requirements defined in the standard.
What is the maximum power dissipation for SZMMSZ5259BT1 on FR−5 board?
SZMMSZ5259BT1 is rated for 500 mW total power dissipation on FR−5 board at lead temperature (TL) = 75°C, with linear derating of 6.7 mW/°C above that temperature. This value is validated per Note 1 in the datasheet using the minimum recommended footprint (3.5 × 1.5 inches).
How does the thermal resistance of SZMMSZ5259BT1 affect its real-world performance?
SZMMSZ5259BT1 has RJA = 340°C/W and RJL = 150°C/W, meaning its junction temperature rises significantly with ambient or lead temperature. At 500 mW dissipation and TL = 75°C, TJ reaches ~126°C - well within the −55°C to +150°C range but requiring careful PCB copper area design to avoid exceeding limits.
What is the leakage current specification for SZMMSZ5259BT1 at 30 V reverse bias?
SZMMSZ5259BT1 exhibits a maximum reverse leakage current (IR) of 0.1 µA at VR = 30 V and TA = 25°C. This ultra-low leakage supports high-impedance bias networks and minimizes standby power loss in always-on voltage monitor circuits using the SZMMSZ5259BT1.
SZMMSZ5259BT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 39 V
- Tolerance:
- ±5%
- Power - Max:
- 500 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:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
SZMMSZ5259BT1 FAQ
1.How can I place an order for SZMMSZ5259BT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMSZ5259BT1 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 SZMMSZ5259BT1 reliable?
The price and inventory of SZMMSZ5259BT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ5259BT1 is usually 5 days.
3.What payment methods are accepted for SZMMSZ5259BT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ5259BT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMSZ5259BT1?
SZMMSZ5259BT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMSZ5259BT1 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 SZMMSZ5259BT1?
For technical support, including SZMMSZ5259BT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ5259BT1 requirements.
6.How does Aetrix verify that SZMMSZ5259BT1 is sourced from the original manufacturer or authorized distributors?
All SZMMSZ5259BT1 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 SZMMSZ5259BT1 meets industry standards.
7.What is the process for return or replacement of SZMMSZ5259BT1?
All SZMMSZ5259BT1 units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ5259BT1, 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 SZMMSZ5259BT1 part is unused and in its original packaging.
Return procedure for SZMMSZ5259BT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZMMSZ5259BT1 Tags
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