MMSZ5240BT1 ON Semiconductor Zener Diode (Small Outline Diode) In Stock
ON Semiconductor MMSZ5240BT1 is a single silicon zener diode in an SOD-123 (Small Outline Diode) surface-mount package, rated for voltage regulation with a maximum dynamic impedance of 17 Ω. Note: this part is listed as obsolete and is not REACH compliant. Remaining stock may be available through distributors worldwide.
- Manufacturer
- ON Semiconductor
- Package
- Small Outline Diode
- Pin Count
- 2
- Lifecycle
- OBSOLETE
- Datasheet
- MMSZ5240BT1 Datasheet PDF
- Category
- Zener Diode
- Price
- From $0.0338(MOQ 1)
- Temp Range
- -55.0°C to 150.0°C
- RoHS
- Non-compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Single silicon zener diode in a compact SOD-123 (R-PDSO-G2) surface-mount package for dense PCB voltage-clamping layouts
- Maximum dynamic impedance of 17 Ω provides predictable voltage regulation behavior across the zener operating current range
- Silicon diode element delivers stable zener breakdown voltage regulation for overvoltage protection and reference voltage applications
- SOD-123 two-terminal package enables automated SMT assembly with standard pick-and-place equipment and reflow soldering
Applications
The MMSZ5240BT1 is used in overvoltage clamping circuits, voltage reference networks, and transient suppression on low-power PCBs where a compact SOD-123 silicon zener is required. Its maximum 17 Ω dynamic impedance suits applications where load regulation accuracy is not critical, such as biasing networks, back-EMF clamps in motor drives, and ESD protection on signal lines. Note that this part is obsolete and not REACH compliant, so it is appropriate only for legacy board repairs or applications exempt from REACH substance restrictions.
Specifications
| Pbfree Code | No |
| Manufacturer Package Code | 425-04 |
| Reach Compliance Code | Not Compliant |
| YTEOL | 0 |
| Configuration | SINGLE |
| Diode Element Material | SILICON |
| Diode Type | ZENER DIODE |
| Dynamic Impedance-Max | 17Ω |
| JESD-30 Code | R-PDSO-G2 |
| JESD-609 Code | e0 |
| Knee Impedance-Max | 600Ω |
| Number of Elements | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 235 |
| Polarity | UNIDIRECTIONAL |
| Power Dissipation-Max | 0.5W |
| Qualification Status | Not Qualified |
| Reference Voltage-Nom | 10V |
| Reverse Current-Max | 3 µA |
| Reverse Test Voltage | 8V |
| Surface Mount | YES |
| Technology | ZENER |
| Terminal Finish | Tin/Lead (Sn/Pb) |
| Terminal Form | GULL WING |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Voltage Tol-Max | 5% |
| Working Test Current | 20mA |
| ## MMSZ5240BT1 Alternates Showing results | Image |
| Package | Small Outline Diode |
Compliance & Regulatory
| RoHS Status | Non-compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8541.10.00.50 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for MMSZ5240BT1:
Frequently Asked Questions
What is the maximum dynamic impedance of the MMSZ5240BT1 and how does it affect voltage regulation accuracy?
The MMSZ5240BT1 has a maximum dynamic impedance of 17 Ω at its rated zener operating current. A higher dynamic impedance means the zener output voltage shifts more with changes in current — for every 1 mA change in zener current, the regulated voltage can vary by up to 17 mV. This is acceptable for loose overvoltage clamping but is too imprecise for tight voltage reference applications requiring regulation within ±1% of a set voltage.
Which board repair or legacy design scenarios justify using the obsolete MMSZ5240BT1?
Legacy industrial control boards manufactured before RoHS and REACH regulations often used non-compliant zener diodes like the MMSZ5240BT1 in SOD-123 packages. Repairing such boards for non-EU markets or military exemptions may require exact electrical replacements at the same 10 V zener voltage and 17 Ω maximum impedance to avoid redesigning surrounding bias networks. In these cases, remaining distributor stock of MMSZ5240BT1 is a direct drop-in for the original footprint.
What package does the MMSZ5240BT1 use and what are its key physical dimensions for PCB layout?
The MMSZ5240BT1 uses an SOD-123 package (JEDEC R-PDSO-G2) with a body length of approximately 2.7 mm, a body width of 1.6 mm, and a lead pitch of approximately 3.5 mm. The 2-terminal SOD-123 footprint is one of the most common surface-mount diode outlines, compatible with standard IPC-7351 land patterns and pick-and-place nozzles used across automated SMT lines.
What Pb-free or RoHS-compliant zener diode could replace the MMSZ5240BT1 in a new design?
Since the MMSZ5240BT1 is listed as not REACH compliant and obsolete, new designs should substitute a Pb-free SOD-123 zener at the same breakdown voltage with a maximum dynamic impedance at or below 17 Ω. ON Semiconductor's MMSZ5240BT1G (the -G suffix denotes Pb-free packaging) is the direct RoHS-compliant equivalent, using the same SOD-123 footprint and silicon element with a 10 V nominal zener voltage and unchanged electrical characteristics.
Related Guides
CL31A107MQHNNNE 1206 100 uF MLCC Selection Guide
How to choose CL31A107MQHNNNE and related 1206 MLCCs for low-voltage bulk capacitance and regulator stability.
Jul 2, 2026
CL05B103KB5NNNC 0402 10 nF X7R MLCC Selection Guide
How to choose CL05B103KB5NNNC and related 0402 MLCCs for bypassing, filtering, voltage derating, and sourcing.
Jul 2, 2026
ADAQ7768-1 Design Guide for Precision Vibration and Dynamic Signal Measurement
Design ADAQ7768-1 precision data acquisition channels for vibration and dynamic sensing with the right bandwidth, reference, clock, and layout choices.
Jun 30, 2026
AD5204BRZ10 Design Guide for SPI-Controlled Gain and Offset Calibration
Design AD5204BRZ10 digital potentiometer calibration loops with bounded trim span, safe wiper current, clean SPI routing, and reliable startup codes.
Jun 30, 2026
Why Buy from FindMyChip
About ON Semiconductor
ON Semiconductor (onsemi) provides intelligent power and sensing technologies for automotive, industrial, IoT, and cloud infrastructure applications.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $0.0760 | $0.08 |
| 84+ | $0.0675 | $5.67 |
| 176+ | $0.0475 | $8.36 |
| 742+ | $0.0450 | $33.39 |
| 1054+ | $0.0342 | $36.05 |
| 3000+ | $0.0338 | $101.40 |
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“We've been using FindMyChip for 2 years. Pricing is consistently 20-30% below Mouser/DigiKey for volume orders.”