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onsemi MMSZ4684
- Part No.:
- MMSZ4684
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ4684.pdf
- Description:
- DIODE ZENER 3.3V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:6,937
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Product details
Overview
MMSZ4684 from Fairchild Semiconductor is a 3.3 V, 500 mW surface-mount Zener diode in SOD-123 package, rated for 50 µA test current, with ±0.165 V zener voltage tolerance and 950 mV delta-VZ over 10–100 µA current range, used for voltage regulation and reference in low-power analog circuits.
For engineers reviewing the MMSZ4684 datasheet, pinout, applications, or equivalent options, key selection factors include its 3.3 V nominal zener voltage, 7.5 µA reverse leakage at 1.5 V, 900 mV forward voltage at 10 mA, Class 3 HBM ESD rating (>16 kV), and thermal resistance of 340°C/W junction-to-ambient.
Technical Context
The MMSZ4684 operates as a precision voltage reference diode with stable breakdown behavior under DC bias at 50 µA, exhibiting tight VZ distribution (3.14–3.47 V) and low dynamic impedance implied by ∆VZ = 950 mV across one-decade current change. Its SOD-123 footprint enables drop-in replacement for mini-MELF (LL-34) layouts without board redesign.
Thermal performance is defined by 340°C/W RθJA on FR-4/FR-5 PCBs and 150°C/W RθJL to lead, supporting reliable operation up to 150°C junction temperature. The device meets Class 3 HBM ESD immunity (>16 kV), making it suitable for handling in standard assembly environments without special static control beyond typical ESD protocols.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 3.3 V at 50 µA - defines primary regulation point for low-current references |
| Zener Voltage Range | 3.14 V to 3.47 V - ensures predictable clamping within ±4.5% tolerance band |
| Reverse Leakage | 7.5 µA at VR = 1.5 V - low off-state current minimizes parasitic loading in high-impedance nodes |
| Forward Voltage | 900 mV at IF = 10 mA - supports bidirectional protection or dual-use in clamp+rectifier roles |
| Power Dissipation | 500 mW at 25°C - enables stable regulation in compact SOD-123 without heatsinking |
| ESD Rating | >16 kV HBM Class 3 - eliminates need for external ESD protection in most consumer-grade assemblies |
| Junction Temp Range | −55°C to +150°C - supports automotive under-hood and industrial ambient conditions |
Pinout & Package
SOD-123 plastic surface-mount package (Package Code D6), 2-terminal unidirectional Zener diode with cathode marked by "CK" top-side marking. Dimensions: 1.40–1.80 mm length (A), 2.55–2.85 mm width (B), 0.88–1.18 mm height (C); land pad pitch 0.91 mm, width 1.22 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Zener cathode terminal | Connected to regulated voltage node; reverse-biased during normal operation |
| 2 (Anode) | Zener anode terminal | Connected to ground or lower-potential rail; completes bias path for breakdown conduction |
Key Features
| Feature | Design Value |
|---|---|
| Same footprint as mini-MELF (LL-34) | Enables direct layout reuse on legacy designs using glass diodes without re-spinning PCBs |
| 500 mW power rating on FR-4 | Delivers higher regulation headroom than standard 250 mW SOD-123 Zeners in same footprint |
| Class 3 HBM ESD rating (>16 kV) | Reduces risk of field failure due to handling damage in automated SMT lines and end-user repair |
| Low ∆VZ (950 mV) | Indicates stable zener impedance across operating current range, improving reference accuracy in varying load conditions |
Applications
| USB Port Voltage Clamp | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Clamping transient overvoltage on USB 3.3 V VBUS line during hot-plug events or ESD strikes. IC Role / Device Role / Timing Role: Zener clamping element providing fast, low-capacitance overvoltage protection. Use Value: 3.3 V nominal breakdown aligns precisely with USB logic supply; 950 mV ∆VZ ensures consistent clamping across varying surge currents. | Use Scenario: Generating clean, temperature-stable reset threshold for 3.3 V microcontrollers during power-up and brownout. IC Role / Device Role / Timing Role: Precision voltage reference defining reset assertion level via resistor divider. Use Value: Tight 3.14–3.47 V VZ window guarantees reset release within spec; Class 3 ESD rating prevents latch-up during board handling. |
| Industrial Sensor Signal Conditioning | Low-Power IoT Node Reference |
Use Scenario: Providing stable bias voltage for op-amp input stages in 4–20 mA loop-powered transmitters. IC Role / Device Role / Timing Role: Low-current zener reference supplying excitation voltage to bridge sensors. Use Value: 7.5 µA IR at 1.5 V minimizes quiescent current draw; −55°C to +150°C TJ range supports extended industrial temperature operation. | Use Scenario: Supplying reference voltage to ADC and LDO enable inputs in battery-powered BLE sensor nodes. IC Role / Device Role / Timing Role: Ultra-low-power voltage reference enabling sub-µA sleep-mode regulation. Use Value: 50 µA test current matches typical ADC reference divider currents; SOD-123 size fits dense RF module layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX384-B3V3 | 3.3 V nominal, 300 mW rating, SOD-323 package, 500 nA IR at 1 V | Lower power, smaller footprint, lower leakage - suited for ultra-low-power but less robust clamping | Select when board space is critical and peak power < 300 mW; not recommended for 500 mW surge handling |
| 1N4728A | 3.3 V nominal, 1 W rating, DO-41 through-hole package, 10 µA IR at 1 V | Higher power, through-hole mounting, higher leakage - suited for prototyping or high-surge legacy designs | Select for breadboard evaluation or where thermal mass >500 mW is required; incompatible with SMT-only production |
Compared with BZX384-B3V3 and 1N4728A, the MMSZ4684 uniquely balances 500 mW capability, SOD-123 surface-mount compatibility, and 7.5 µA leakage - making it optimal for production-grade 3.3 V regulation where mini-MELF footprint reuse and moderate surge resilience are required.
Availability
MMSZ4684 is available at Aetrix Electronics and suitable for USB interface protection, microcontroller reset generation, industrial sensor signal conditioning, and low-power IoT node reference requiring stable component supply across automotive, industrial, and consumer programs.
Supply support for MMSZ4684 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.
The MMSZ series was designed as a family of general-purpose, medium-current Zener diodes targeting cost-sensitive, high-volume surface-mount applications requiring reliable voltage regulation in compact packages.
FAQ
What is the nominal zener voltage and test current for MMSZ4684?
The MMSZ4684 has a nominal zener voltage of 3.3 V measured at a test current of 50 µA. This value is specified in the Electrical Characteristics table of the Fairchild datasheet, with a guaranteed range of 3.14 V to 3.47 V under the same conditions. The MMSZ4684 maintains this regulation point across its qualified operating temperature range and is intended for low-current reference and clamping applications where precision and stability are required.
Does MMSZ4684 support surface-mount assembly with standard reflow profiles?
Yes, the MMSZ4684 is qualified for standard lead-free reflow soldering with a maximum lead solder temperature of 260°C for up to 10 seconds. Its SOD-123 package and plastic construction meet JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for typical SMT processes. The MMSZ4684 can be placed and reflowed alongside other RoHS-compliant components without special thermal profiling, provided board-level thermal mass and soak time comply with IPC-7095 guidelines.
What is the reverse leakage current specification for MMSZ4684?
The reverse leakage current (IR) for MMSZ4684 is specified as 7.5 µA maximum at VR = 1.5 V and TA = 25°C. This parameter reflects the diode's off-state conduction under sub-breakdown bias and is critical for high-impedance reference divider networks. The MMSZ4684's low IR contributes to minimal error in precision voltage sensing applications, especially when paired with high-value resistors in reset or bias circuits.
Is MMSZ4684 compatible with mini-MELF (LL-34) PCB footprints?
Yes, the MMSZ4684 in SOD-123 package is explicitly designed to match the land pattern and mechanical envelope of glass mini-MELF (LL-34) devices. Fairchild's datasheet confirms identical footprint dimensions and recommends the SOD-123 as a "convenient alternative" to LL-34. The MMSZ4684 allows direct substitution without PCB modification, retaining the same solder joint geometry and thermal path characteristics as its through-hole counterpart.
What is the thermal resistance junction-to-ambient for MMSZ4684 on standard PCBs?
The thermal resistance junction-to-ambient (RθJA) for MMSZ4684 is 340°C/W when mounted on FR-4 or FR-5 printed circuit boards. This value assumes standard 1 oz copper traces and no additional copper pour or thermal vias. The MMSZ4684's RθJA enables safe operation at full 500 mW dissipation only up to approximately 45°C ambient; derating is required above that temperature per the 6.7 mW/°C slope specified in the Absolute Maximum Ratings table.
MMSZ4684 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 3.3 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- -
- Current - Reverse Leakage @ Vr:
- 7.5 µA @ 1.5 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
MMSZ4684 FAQ
1.How can I place an order for MMSZ4684 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ4684 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 MMSZ4684 reliable?
The price and inventory of MMSZ4684 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ4684 is usually 5 days.
3.What payment methods are accepted for MMSZ4684?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ4684 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ4684?
MMSZ4684 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ4684 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 MMSZ4684?
For technical support, including MMSZ4684 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ4684 requirements.
6.How does Aetrix verify that MMSZ4684 is sourced from the original manufacturer or authorized distributors?
All MMSZ4684 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 MMSZ4684 meets industry standards.
7.What is the process for return or replacement of MMSZ4684?
All MMSZ4684 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ4684, 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 MMSZ4684 part is unused and in its original packaging.
Return procedure for MMSZ4684:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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