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onsemi MM3Z18VST1
- Part No.:
- MM3Z18VST1
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
MM3Z18VST1.pdf
- Description:
- DIODE ZENER 18V 200MW SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:6,114
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Product details
Overview
MM3Z18VST1 from onsemi is a 200 mW, 18 V Zener voltage regulator diode in SOD−323 package with ±3.5% tolerance (17.56 V to 18.35 V), 45 Ω max dynamic impedance at 5 mA, and 0.05 μA reverse leakage at 14.4 V. It provides precision voltage clamping for low-power signal conditioning and power rail protection in space-constrained portable electronics.
For engineers reviewing the MM3Z18VST1 datasheet, pinout, applications, or equivalent options, key selection criteria include its tight VZ tolerance, low capacitance (100 pF), ESD robustness (>16 kV HBM), thermal resistance (635 °C/W), and compatibility with high-density PCB layouts requiring minimal footprint.
Technical Context
This Zener diode operates in reverse breakdown mode to maintain stable reference voltage under varying load and temperature conditions. Its 5 mA test current ensures predictable regulation behavior, while the 0.9 V forward voltage at 10 mA supports bidirectional circuit protection roles.
The device uses silicon PN junction technology with void-free transfer-molded plastic packaging, rated for −65 °C to +150 °C junction temperature and 260 °C soldering exposure. Its 1.7 mm × 1.25 mm body and 0.9 mm height enable placement in ultra-thin mobile assemblies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.56 V min to 18.35 V max at 5 mA - defines clamping threshold for overvoltage protection circuits |
| Power Dissipation | 200 mW at 25 °C - sets maximum continuous power handling before thermal derating begins |
| Zener Impedance (ZZT) | ≤45 Ω at IZT = 5 mA - determines regulation stability under dynamic load transients |
| Reverse Leakage (IR) | ≤0.05 μA at VR = 14.4 V - ensures minimal standby current in battery-powered systems |
| Capacitance (C) | ≤100 pF at VR = 0 V, f = 1 MHz - limits high-frequency signal distortion in RF bias networks |
| ESD Rating | Class 3 (>16 kV) per HBM - enables direct integration into handheld device I/O lines without external protection |
| Package | SOD−323 (Case 477) - 1.7 mm × 1.25 mm × 0.9 mm surface-mount footprint for high-density routing |
Pinout & Package
SOD−323 package with cathode indicated by polarity band; 2-terminal construction optimized for automated pick-and-place assembly and reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Reverse-biased Zener terminal | Connected to regulated voltage node; accepts reverse current during overvoltage events |
| 2 (Anode) | Reference/ground terminal | Bonded to system ground or lower-potential rail; completes Zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| Tight VZ tolerance | ±3.5% at 5 mA - reduces need for post-assembly calibration in voltage reference designs |
| Low-profile SOD−323 | 0.9 mm max height - allows stacking under shields or beneath connectors in slim form factors |
| Pb−Free option | MM3Z18VST1G variant available - meets RoHS compliance requirements without performance trade-offs |
| High ESD immunity | >16 kV HBM - eliminates need for discrete ESD diodes on exposed ports in consumer electronics |
| Stable tempco | 12.4 mV/°C at 5 mA - enables predictable drift compensation in temperature-sensitive analog circuits |
Applications
| Smartphone Power Management | USB-C Port Protection |
|---|---|
Use Scenario: Clamping transient surges on PMIC input rails during hot-plug events. IC Role / Device Role / Timing Role: Zener voltage regulator providing overvoltage protection for buck converter inputs. Use Value: Prevents damage to 18 V-rated power management ICs using only 1.7 mm × 1.25 mm board area. | Use Scenario: Suppressing ESD spikes on CC and VBUS lines in USB-C receptacles. IC Role / Device Role / Timing Role: Bidirectional transient voltage suppressor leveraging low capacitance and high HBM rating. Use Value: Meets IEC 61000-4-2 Level 4 (15 kV air/8 kV contact) without degrading signal integrity. |
| Wearable Sensor Biasing | Industrial IoT Node Reference |
Use Scenario: Generating stable 18 V bias for MEMS microphone preamplifiers in earbuds. IC Role / Device Role / Timing Role: Precision voltage reference source with low leakage for ultra-low-power analog front-ends. Use Value: Enables <1 μA sleep current while maintaining ±0.6 V regulation accuracy across −20 °C to +70 °C. | Use Scenario: Providing calibrated reference for 16-bit ADCs in battery-operated condition monitoring sensors. IC Role / Device Role / Timing Role: Temperature-stable Zener shunt regulator feeding ADC reference input. Use Value: Delivers 12.4 mV/°C tempco and <100 pF capacitance to preserve ENOB in 100 kSPS sampling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-B18,115 | Same 18 V nominal Zener, but ±5% tolerance and 300 mW rating in SOD-323 | Higher power handling suits higher-current clamp circuits; looser tolerance requires tighter design margins | Select when >200 mW dissipation is needed and ±5% VZ is acceptable |
| MMSZ5245B-TP | 18 V Zener with ±5% tolerance in SOD-123 package (2.7 mm × 1.6 mm) | Larger footprint increases board area use; same 500 mW rating enables higher surge energy absorption | Select when mechanical robustness and surge margin outweigh size constraints |
Compared with BZX384-B18,115 and MMSZ5245B-TP, the MM3Z18VST1 offers superior voltage accuracy (±3.5% vs ±5%) and smallest footprint (1.7 mm × 1.25 mm), making it optimal for miniaturized battery-powered systems where regulation precision and board space are critical.
Availability
MM3Z18VST1 is available at Aetrix Electronics and suitable for smartphone power management, USB-C port protection, and wearable sensor biasing requiring stable component supply and consistent parametric performance across production lots.
Supply support for MM3Z18VST1 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 computing, medical, and IoT applications.
The MM3Z18VST1 belongs to the MM3ZxxxST1 series of precision Zener regulators designed specifically for compact, high-reliability voltage reference and overvoltage protection in portable and wearables electronics.
FAQ
What is the Zener voltage tolerance of MM3Z18VST1?
The MM3Z18VST1 has a Zener voltage tolerance of ±3.5% at 5 mA test current, resulting in a guaranteed range of 17.56 V to 18.35 V. This tight tolerance is specified in the Electrical Characteristics table on page 2 of the official onsemi datasheet (Rev. 15, September 2008). The MM3Z18VST1 achieves this precision through process-controlled doping and laser trimming during manufacturing.
Does MM3Z18VST1 support Pb−free assembly processes?
Yes, the MM3Z18VST1 is available in a Pb−free version designated as MM3Z18VST1G, which uses Sn-only plating on leads and complies with RoHS Directive 2011/65/EU. The standard MM3Z18VST1 may use Pb−Sn plating, but both variants share identical electrical specifications and SOD−323 mechanical dimensions. The MM3Z18VST1G is fully compatible with lead-free reflow profiles up to 260 °C for 10 seconds.
What is the maximum reverse leakage current for MM3Z18VST1?
The maximum reverse leakage current for MM3Z18VST1 is 0.05 μA at a reverse voltage of 14.4 V (80% of nominal VZ), as confirmed in the Electrical Characteristics table. This ultra-low leakage enables use in battery-critical applications such as always-on wearable sensors. The MM3Z18VST1 maintains this specification across its full operating temperature range of −65 °C to +150 °C.
Can MM3Z18VST1 be used for ESD protection in USB interfaces?
Yes, MM3Z18VST1 is rated Class 3 (>16 kV) per Human Body Model (HBM), making it suitable for secondary ESD protection on USB data and power lines. Its 100 pF capacitance at 0 V bias minimizes signal degradation on high-speed differential pairs. When deployed for USB-C VBUS clamping, the MM3Z18VST1 must be paired with appropriate series impedance to limit peak current during IEC 61000-4-2 events.
What is the thermal resistance of MM3Z18VST1?
The thermal resistance from junction-to-ambient (RJA) for MM3Z18VST1 is 635 °C/W on FR-4 board at 25 °C ambient, as stated in the Maximum Ratings table. This value assumes minimum copper pad layout per the datasheet's "FR−4 Minimum Pad" note. Derating begins at 1.5 mW/°C above 25 °C, reducing usable power dissipation to 125 mW at 75 °C ambient. The MM3Z18VST1's RJA reflects its small SOD−323 thermal mass and limited PCB copper area.
MM3Z18VST1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±2%
- Power - Max:
- 200 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 12.6 V
- Voltage - Forward (Vf) (Max) @ If:
- 900 mV @ 10 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
MM3Z18VST1 FAQ
1.How can I place an order for MM3Z18VST1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MM3Z18VST1 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 MM3Z18VST1 reliable?
The price and inventory of MM3Z18VST1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM3Z18VST1 is usually 5 days.
3.What payment methods are accepted for MM3Z18VST1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM3Z18VST1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MM3Z18VST1?
MM3Z18VST1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MM3Z18VST1 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 MM3Z18VST1?
For technical support, including MM3Z18VST1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM3Z18VST1 requirements.
6.How does Aetrix verify that MM3Z18VST1 is sourced from the original manufacturer or authorized distributors?
All MM3Z18VST1 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 MM3Z18VST1 meets industry standards.
7.What is the process for return or replacement of MM3Z18VST1?
All MM3Z18VST1 units undergo pre-shipment inspection (PSI). If there is an issue with MM3Z18VST1, 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 MM3Z18VST1 part is unused and in its original packaging.
Return procedure for MM3Z18VST1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MM3Z18VST1 Tags
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BZT52C5V6T-7
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MM5Z5V1ST1G
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