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onsemi MMSZ5256ET1G
- Part No.:
- MMSZ5256ET1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5256ET1G.pdf
- Description:
- DIODE ZENER 30V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:1,122
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Product details
Overview
MMSZ5256ET1G from onsemi is a 30 V ±5% Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 4.2 mA test current (IZT), 49 Ω dynamic impedance (ZZT), and 0.1 µA leakage current at 23 V reverse bias - used for precision voltage reference and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMSZ5256ET1G datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage tolerance, thermal derating behavior, junction-to-lead thermal resistance, and HBM ESD rating - all critical for stable regulation in space-constrained, thermally demanding PCB layouts.
Technical Context
This device operates as a two-terminal silicon Zener diode optimized for voltage regulation and clamping in DC bias networks. It exhibits a nominal 30 V breakdown at IZT = 4.2 mA, with ZZT = 49 Ω measured at 1 kHz AC signal superimposed on DC bias, and temperature coefficient near +0.085 %/°C in the 28–32 V range.
The SOD-123 package enables automated placement while maintaining 150 °C maximum junction temperature and −55 °C to +150 °C storage range. Its cathode-band polarity marking and Pb-free construction comply with RoHS and AEC-Q101 requirements when ordered as SZMMSZ5256ET1G.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 28.5 V min / 30 V nom / 31.5 V max at IZT = 4.2 mA - defines regulated output voltage window under standard test conditions |
| Power Dissipation (PD) | 500 mW at TL = 75 °C on FR-5 board - sets maximum continuous DC power handling before thermal derating begins |
| Zener Impedance (ZZT) | 49 Ω max at IZT = 4.2 mA, f = 1 kHz - determines AC regulation error under small-signal ripple conditions |
| Leakage Current (IR) | 0.1 µA max at VR = 23 V - ensures minimal standby current draw in high-impedance bias networks |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - supports robust handling during manual assembly and field operation |
| Junction-to-Lead RθJL | 150 °C/W - enables accurate thermal modeling of local heating under pulsed or transient loads |
Pinout & Package
SOD-123 surface-mount package: 1.60 mm × 2.69 mm × 1.16 mm body, void-free thermosetting plastic case, corrosion-resistant finish, UL 94 V-0 flammability rating, cathode indicated by band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated voltage node; reverse-biased terminal where Zener breakdown occurs |
| 2 (Non-banded End) | Anode | Connected to circuit ground or lower-potential rail; completes current path during regulation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating | Enables use in medium-current biasing and clamping without external heat sinking on standard FR-5 PCBs |
| ±5% Zener Voltage Tolerance | Supports predictable regulation across production lots without post-assembly trimming |
| 16 kV HBM ESD Robustness | Reduces risk of field failure in handheld or exposed-interface applications without added protection circuitry |
| Optimized SOD-123 Footprint | Allows high-density placement in compact power management sections of IoT sensor nodes and portable electronics |
| AEC-Q101 Qualified Variant | SZMMSZ5256ET1G meets automotive-grade reliability and traceability requirements for under-hood and infotainment systems |
Applications
| Industrial Sensor Biasing | USB Port Overvoltage Clamp |
|---|---|
|
Use Scenario: Providing stable 30 V reference for analog front-end amplifiers in pressure and temperature transducers. IC Role / Device Role / Timing Role: Zener diode acting as shunt voltage reference and noise filter in op-amp feedback network. Use Value: Maintains <±1% output stability over −40 °C to +85 °C ambient due to known TC and low ZZT. |
Use Scenario: Clamping transient surges on USB VBUS line during hot-plug events or ESD discharge. IC Role / Device Role / Timing Role: Fast-acting shunt protector diverting >10 A surge pulses away from downstream USB controller ICs. Use Value: Withstands 225 W nonrepetitive 8×20 µs pulses and limits clamped voltage to ≤31.5 V, protecting 3.3 V logic rails. |
| Low-Power MCU Reset Circuit | LED Driver Current Reference |
|
Use Scenario: Generating precise reset threshold for microcontrollers operating from 3.3 V or 5 V supplies. IC Role / Device Role / Timing Role: Zener-based voltage divider feeding comparator input to trigger reset when supply drops below safe level. Use Value: Tight 30 V ±5% tolerance ensures consistent reset point across temperature and manufacturing variance. |
Use Scenario: Setting constant current for white LED strings in battery-powered lighting modules. IC Role / Device Role / Timing Role: Shunt regulator establishing reference voltage across current-sense resistor in linear LED driver topology. Use Value: Low 0.1 µA leakage at 23 V ensures negligible error in sub-10 mA LED current setting accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C30LT1G | Same 30 V nominal Zener, but 350 mW rating and higher ZZT (70 Ω); SOT-23 package with different footprint | Lower power handling limits use in sustained-clamp scenarios; smaller size suits ultra-dense layouts | Select when board area is constrained and peak pulse energy remains below 150 W |
| MMSZ4702T1G | 24 V nominal Zener, same SOD-123 package and 500 mW rating, but tighter 2% tolerance and lower ZZT (30 Ω) | Used where lower reference voltage and improved regulation accuracy are required | Choose for precision analog references needing <±0.5% total error budget over temperature |
Compared with MMSZ5256ET1G, BZX84-C30LT1G trades power margin for footprint reduction, while MMSZ4702T1G offers superior regulation accuracy at a lower voltage - both require layout revision due to differing packages or voltage targets.
Availability
MMSZ5256ET1G is available at Aetrix Electronics and suitable for industrial sensor biasing, USB port overvoltage clamp, and low-power MCU reset circuits requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for MMSZ5256ET1G 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
MMSZ5256ET1G belongs to the MMSZ52xxET1G Zener regulator series designed for general-purpose, medium-current voltage reference and transient suppression in space-constrained surface-mount designs.
FAQ
What is the Zener voltage tolerance of MMSZ5256ET1G?
MMSZ5256ET1G has a nominal Zener voltage of 30 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 28.5 V and 31.5 V when tested at IZT = 4.2 mA and TL = 30 °C. This tolerance is guaranteed across production lots and supports predictable circuit design without calibration.
Can MMSZ5256ET1G be used in automotive applications?
Yes - the automotive-grade variant SZMMSZ5256ET1G is AEC-Q101 qualified and PPAP capable, with enhanced process controls and traceability. The standard MMSZ5256ET1G is not automotive-qualified, but shares identical electrical and thermal specs; only the SZ-prefix version meets full automotive reliability requirements.
What is the maximum surge power rating for MMSZ5256ET1G?
MMSZ5256ET1G supports a nonrepetitive peak surge power of 225 W for an 8 × 20 µs rectangular pulse waveform at TA = 25 °C. This rating enables reliable transient suppression in power supply inputs and interface lines subject to ESD or lightning-induced surges.
How does thermal derating affect MMSZ5256ET1G's power handling?
MMSZ5256ET1G is rated for 500 mW at lead temperature (TL) = 75 °C on FR-5 board, with linear derating of 6.7 mW/°C above that point. At TL = 100 °C, its usable power drops to ~333 mW - requiring careful thermal layout to avoid exceeding junction temperature limits.
Is MMSZ5256ET1G compatible with lead-free reflow soldering processes?
Yes - MMSZ5256ET1G is Pb-free and rated for maximum soldering temperature of 260 °C for 10 seconds, fully compatible with standard lead-free reflow profiles. Its void-free thermosetting plastic case and corrosion-resistant finish ensure reliable joint formation and long-term interconnect integrity.
MMSZ5256ET1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- MMSZ52xxxT1G
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 30 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 23 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
MMSZ5256ET1G FAQ
1.How can I place an order for MMSZ5256ET1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5256ET1G 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 MMSZ5256ET1G reliable?
The price and inventory of MMSZ5256ET1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5256ET1G is usually 5 days.
3.What payment methods are accepted for MMSZ5256ET1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5256ET1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5256ET1G?
MMSZ5256ET1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5256ET1G 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 MMSZ5256ET1G?
For technical support, including MMSZ5256ET1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5256ET1G requirements.
6.How does Aetrix verify that MMSZ5256ET1G is sourced from the original manufacturer or authorized distributors?
All MMSZ5256ET1G 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 MMSZ5256ET1G meets industry standards.
7.What is the process for return or replacement of MMSZ5256ET1G?
All MMSZ5256ET1G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5256ET1G, 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 MMSZ5256ET1G part is unused and in its original packaging.
Return procedure for MMSZ5256ET1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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