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onsemi MMSZ5259ET1G
- Part No.:
- MMSZ5259ET1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5259ET1G.pdf
- Description:
- DIODE ZENER 39V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:9,078
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Product details
Overview
MMSZ5259ET1G from onsemi is a 39 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 800 Ω maximum dynamic impedance at 3.2 mA test current and 0.1 µA reverse leakage at 30 V, used for precision voltage reference and overvoltage protection in power supply feedback loops.
For engineers reviewing the MMSZ5259ET1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal resistance (RJL = 150 °C/W), surge capability (225 W, 8 × 20 µs), ESD rating (>16 kV HBM), and SOD-123 footprint compatibility with automated assembly.
Technical Context
This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to maintain stable output voltage under varying load or input conditions. Its 39 V nominal Zener voltage is specified at IZT = 3.2 mA with ±5% tolerance, and it exhibits a positive temperature coefficient above ~5 V, typical for mid-voltage Zeners.
Designed for surface-mount use on FR-4/FR-5 PCBs, the MMSZ5259ET1G delivers regulated voltage with low dynamic impedance (ZZT ≤ 800 Ω) and minimal leakage (IR ≤ 0.1 µA @ VR = 30 V), enabling reliable clamping and reference functions in compact, high-density power management circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 37.05–40.95 V @ IZT = 3.2 mA; ensures stable regulation within ±5% across production units |
| Power Dissipation (PD) | 500 mW @ TL = 75 °C; defines continuous DC power handling on standard FR-5 board |
| Zener Impedance (ZZT) | ≤800 Ω @ IZT = 3.2 mA; determines voltage regulation accuracy under dynamic load changes |
| Reverse Leakage (IR) | ≤0.1 µA @ VR = 30 V; minimizes standby current loss in high-impedance bias networks |
| Thermal Resistance (RJL) | 150 °C/W junction-to-lead; enables accurate thermal modeling for PCB copper pour design |
| ESD Rating | Class 3 (>16 kV HBM); supports robust handling during automated assembly without additional protection |
| Surge Power (Ppk) | 225 W @ 8 × 20 µs pulse; provides transient overvoltage clamping capability in power rails |
Pinout & Package
Package: SOD-123 (1.60 × 2.69 × 1.16 mm), surface-mount, cathode-banded, Pb-free, UL 94 V-0 rated.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated output or higher-potential node; polarity band identifies this terminal |
| 2 (Non-banded End) | Anode | Connected to ground or lower-potential reference point; completes reverse-bias conduction path |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating on FR-5 Board | Enables use in space-constrained power supplies without forced air or heatsinking |
| ±5% Zener Voltage Tolerance | Supports tight regulation requirements in feedback networks of DC-DC converters |
| ESD Rating >16 kV (HBM) | Eliminates need for external ESD protection during board assembly and field operation |
| SOD-123 Small Outline Package | Facilitates high-density layout and compatibility with standard pick-and-place equipment |
| 225 W Nonrepetitive Surge Capability | Provides transient suppression for inductive switching spikes in automotive and industrial systems |
Applications
| Switch-Mode Power Supply Feedback | Overvoltage Protection Clamp |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or forward converter feedback loop using optocoupler-coupled TL431 replacement. IC Role / Device Role / Timing Role: Zener reference element setting precise error amplifier threshold in secondary-side regulation. Use Value: 39 V nominal Zener voltage enables direct interface with common optocoupler CTR ranges while maintaining ±5% regulation accuracy. | Use Scenario: Clamping 48 V rail transients caused by relay coil de-energization or motor commutation in industrial PLC I/O modules. IC Role / Device Role / Timing Role: Passive shunt protector absorbing energy from inductive kickback pulses. Use Value: 225 W surge rating and 800 Ω dynamic impedance ensure fast response and minimal voltage overshoot during 8 × 20 µs transients. |
| Reference Voltage Source | Microcontroller Reset Circuit |
Use Scenario: Providing stable 39 V reference for analog-to-digital conversion scaling in battery monitoring systems. IC Role / Device Role / Timing Role: Precision voltage reference for ADC full-scale calibration and offset compensation. Use Value: Low 0.1 µA leakage at 30 V ensures negligible loading on high-impedance divider networks feeding ADC inputs. | Use Scenario: Generating clean reset signal for microcontrollers operating from unregulated 36–42 V automotive battery inputs. IC Role / Device Role / Timing Role: Zener-based brown-out detector triggering POR circuit when supply drops below 39 V threshold. Use Value: Tight ±5% tolerance and predictable temperature coefficient enable repeatable reset voltage across −40 °C to +125 °C. |
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 SOT-23 package (larger footprint, higher RJA = 350 °C/W) | Lower power density; less suitable for ultra-compact layouts requiring SOD-123 footprint | Select when existing SOT-23 land pattern is fixed and thermal margin allows higher ambient rise |
| MMSZ5259BS | Same electrical specs but legacy non-Pb-free SOD-123 variant (no "G" suffix, RoHS non-compliant) | Not acceptable for new designs targeting modern environmental compliance standards | Only consider for legacy repair or obsolescence mitigation where Pb-free is not mandated |
Compared with BZX84-C39LT1G and MMSZ5259BS, the MMSZ5259ET1G offers superior thermal performance (RJL = 150 °C/W vs. ~200 °C/W typical for SOT-23), smaller footprint, and guaranteed Pb-free compliance-making it optimal for new automotive and industrial designs requiring high reliability and regulatory alignment.
Availability
MMSZ5259ET1G is available at Aetrix Electronics and suitable for switch-mode power supplies, overvoltage protection circuits, precision reference sources, and microcontroller reset networks requiring stable component supply and long-term lifecycle support.
Supply support for MMSZ5259ET1G 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, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The MMSZ52xxET1G series belongs to onsemi's general-purpose Zener regulator product line, engineered for medium-current, surface-mount voltage reference and clamping in cost-sensitive, high-volume power management systems.
FAQ
What is the nominal Zener voltage and tolerance of the MMSZ5259ET1G?
The MMSZ5259ET1G has a nominal Zener voltage of 39 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 37.05 V and 40.95 V when tested at IZT = 3.2 mA and thermal equilibrium at 30 °C. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet. The MMSZ5259ET1G maintains this specification across its qualified operating temperature range.
What is the maximum power dissipation rating for the MMSZ5259ET1G under standard PCB conditions?
The MMSZ5259ET1G is rated for 500 mW total power dissipation on an FR-5 board at lead temperature (TL) = 75 °C, with linear derating of 6.7 mW/°C above that temperature. This rating assumes the minimum recommended footprint per onsemi's mechanical specifications. The MMSZ5259ET1G achieves this performance in its SOD-123 package without requiring heatsinking or airflow in most applications.
Does the MMSZ5259ET1G have automotive qualification?
The MMSZ5259ET1G itself is not AEC-Q101 qualified; however, its automotive-grade counterpart SZMMSZ5259ET1G is explicitly listed as AEC-Q101 qualified and PPAP capable in the same datasheet. The MMSZ5259ET1G shares identical electrical and thermal characteristics but lacks the controlled manufacturing site and change documentation required for automotive use. For automotive applications, the SZ prefix version must be selected.
What is the reverse leakage current specification for the MMSZ5259ET1G?
The MMSZ5259ET1G specifies a maximum reverse leakage current (IR) of 0.1 µA at VR = 30 V and TA = 25 °C, as stated in the Electrical Characteristics table. This low leakage ensures minimal parasitic current draw in high-impedance reference or bias networks. The MMSZ5259ET1G maintains this performance across its storage temperature range of −55 °C to +150 °C, with leakage increasing predictably at elevated temperatures.
How is the polarity marked on the MMSZ5259ET1G SOD-123 package?
The MMSZ5259ET1G uses a cathode band to indicate polarity: the banded end (Pin 1) is the cathode, and the non-banded end (Pin 2) is the anode. This marking aligns with JEDEC-standard SOD-123 orientation and is visible under standard optical inspection. The MMSZ5259ET1G also carries a device-specific marking code "CE3" adjacent to the band, confirming its 39 V Zener voltage grade per the datasheet's marking diagram.
MMSZ5259ET1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- MMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
MMSZ5259ET1G FAQ
1.How can I place an order for MMSZ5259ET1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5259ET1G 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 MMSZ5259ET1G reliable?
The price and inventory of MMSZ5259ET1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5259ET1G is usually 5 days.
3.What payment methods are accepted for MMSZ5259ET1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5259ET1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5259ET1G?
MMSZ5259ET1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5259ET1G 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 MMSZ5259ET1G?
For technical support, including MMSZ5259ET1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5259ET1G requirements.
6.How does Aetrix verify that MMSZ5259ET1G is sourced from the original manufacturer or authorized distributors?
All MMSZ5259ET1G 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 MMSZ5259ET1G meets industry standards.
7.What is the process for return or replacement of MMSZ5259ET1G?
All MMSZ5259ET1G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5259ET1G, 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 MMSZ5259ET1G part is unused and in its original packaging.
Return procedure for MMSZ5259ET1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMSZ5259ET1G Tags
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