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onsemi MMSZ5237B
- Part No.:
- MMSZ5237B
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ5237B.pdf
- Description:
- DIODE ZENER 8.2V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:45,000
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Product details
Overview
MMSZ5237B from Fairchild Semiconductor is a 5% tolerance, 8.2 V nominal Zener diode in SOD-123 package, rated for 500 mW power dissipation at 25°C, with 8.0 Ω dynamic impedance at 20 mA test current and 6.5 μA reverse leakage at 6.5 V, used for precision voltage regulation and reference in low-power analog circuits.
For engineers reviewing the MMSZ5237B datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal limits, SOD-123 terminal mapping, and direct alternatives for voltage reference design, ESD protection clamping, and biasing in portable instrumentation and power management subsystems.
Technical Context
The MMSZ5237B operates as a silicon planar Zener diode optimized for stable reverse-breakdown behavior under controlled DC bias. Its 8.2 V nominal Zener voltage is specified at IZ = 20 mA, with tight 5% tolerance and low dynamic impedance (8.0 Ω) ensuring minimal voltage deviation across load variations.
Thermal performance is defined by RθJA = 340°C/W on FR-4 PCB with minimum land pads, limiting maximum junction temperature to +150°C. Reverse leakage remains ≤0.25 μA at VR = 6.5 V, supporting low-current reference stability in battery-powered systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 7.79–8.61 V at IZ = 20 mA; defines precise clamping threshold for overvoltage protection and reference generation |
| Dynamic Impedance (ZZ) | 8.0 Ω max at IZ = 20 mA; ensures <16 mV output shift per 1 mA load change in regulated circuits |
| Power Dissipation (PD) | 500 mW at TA = 25°C; sets maximum continuous DC power handling without derating on standard PCB layout |
| Reverse Leakage (IR) | ≤0.25 μA at VR = 6.5 V; enables ultra-low quiescent current operation in always-on sensor bias networks |
| Forward Voltage (VF) | ≤0.9 V at IF = 10 mA; guarantees predictable forward conduction for dual-direction clamp or polarity detection |
| Thermal Resistance (RθJA) | 340°C/W on FR-4 board; requires ≥100°C/W heatsinking or power reduction above 70°C ambient for safe operation |
Pinout & Package
SOD-123 surface-mount package with cathode band marking; 2-terminal unidirectional Zener configuration requiring no external bias components.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener breakdown return path | Connected to lower-potential node in shunt regulator; carries full load current during regulation |
| Cathode | Zener breakdown terminal / voltage reference output | Provides stable 8.2 V reference point when reverse-biased; marked by band on package body |
Key Features
| Feature | Design Value |
|---|---|
| 5% Zener voltage tolerance | Enables ±0.41 V accuracy at 8.2 V without post-production trimming in cost-sensitive consumer designs |
| Low dynamic impedance (8.0 Ω) | Reduces output voltage variation to <±16 mV across 1 mA load swings, improving ADC reference stability |
| Ultra-low reverse leakage (≤0.25 μA) | Minimizes standby current drain in battery-backed real-time clocks and low-power microcontroller reset circuits |
| SOD-123 footprint compatibility | Supports automated placement and reflow soldering on high-density PCBs with 1.5 mm × 3.5 mm board area |
| 150°C maximum junction temperature | Allows operation in enclosed industrial enclosures up to 85°C ambient with standard thermal relief patterns |
Applications
| Portable Instrumentation | Microcontroller Reset Circuit |
|---|---|
Use Scenario: Precision voltage reference for 12-bit ADC in handheld multimeter with 3.3 V supply rail. IC Role / Device Role / Timing Role: Shunt Zener reference providing stable 8.2 V to resistive divider that scales input range to ADC full scale. Use Value: 8.0 Ω ZZ ensures <±0.02% full-scale error from load-induced drift across 10 kΩ divider impedance. |
Use Scenario: Brown-out detection and clean reset generation for ARM Cortex-M0+ MCU in wearable health monitor. IC Role / Device Role / Timing Role: Zener-clamped voltage supervisor input, triggering reset when VDD drops below 8.2 V × 0.95 = 7.79 V. Use Value: 0.25 μA IR prevents false resets from leakage-induced voltage rise during deep sleep modes. |
| Low-Power Sensor Biasing | ESD Protection Clamp |
Use Scenario: Stable bias voltage for MEMS accelerometer analog front-end in IoT node powered by coin cell. IC Role / Device Role / Timing Role: Low-current Zener reference supplying 8.2 V to op-amp gain-setting network. Use Value: 500 mW PD rating allows 100 μA bias current with 82°C margin to TJ limit at 25°C ambient. |
Use Scenario: Secondary clamping element in USB 2.0 data line ESD protection circuit alongside TVS diode. IC Role / Device Role / Timing Role: Fast-response Zener absorbing residual transients after primary TVS conduction. Use Value: 8.2 V VZ places clamping window between 3.3 V logic level and 12 V system rail, preventing latch-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX584C8V2 | 4% tolerance, 750 mW PD, 15 Ω ZZ at 5 mA; SOD-523 package (1.3 × 0.85 mm) | Higher power rating but larger ZZ reduces regulation accuracy; smaller footprint demands tighter placement tolerances | Select for space-constrained designs needing >500 mW headroom, accepting ±0.33 V VZ spread and higher impedance error |
| MMBZ5237BS | Same VZ range and tolerance, but SOT-23 package (2.9 × 1.3 mm), 350 mW PD, 10 Ω ZZ | Larger footprint eases assembly but lower PD restricts max current to 43 mA before thermal derating | Choose when existing SOT-23 land pattern exists and 350 mW suffices; avoid in high-ambient-temperature environments |
Compared with MMSZ5237B, BZX584C8V2 offers higher power and tighter tolerance but sacrifices regulation precision due to higher ZZ, while MMBZ5237BS trades package size for reduced thermal capacity-both require layout review for thermal and mechanical fit.
Availability
MMSZ5237B is available at Aetrix Electronics and suitable for portable instrumentation, microcontroller reset circuits, and low-power sensor biasing requiring stable component supply with traceable sourcing and lifecycle continuity.
Supply support for MMSZ5237B 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 devices before its acquisition by ON Semiconductor in 2016.
The MMSZ5237B belongs to the MMSZ52xxB Zener diode family designed for general-purpose voltage regulation and reference in commercial-grade consumer and industrial electronics.
FAQ
What is the nominal Zener voltage of the MMSZ5237B?
The MMSZ5237B has a nominal Zener voltage of 8.2 V, with a guaranteed range of 7.79 V to 8.61 V at 20 mA test current and 25°C ambient temperature. This value is specified in the Electrical Characteristics table of the Fairchild datasheet Rev. 1.6 and defines the device's primary regulation point for circuit design calculations involving the MMSZ5237B.
What package type does the MMSZ5237B use?
The MMSZ5237B uses the SOD-123 surface-mount package, a JEDEC DO-219 compliant 2-lead outline measuring 1.5 mm × 3.5 mm. The cathode is identified by a band on the package body, and thermal resistance is specified at 340°C/W on FR-4 PCB with minimum recommended land pads-key parameters confirmed in the Physical Dimensions and Absolute Maximum Ratings sections for the MMSZ5237B.
What is the maximum power dissipation rating for the MMSZ5237B?
The MMSZ5237B is rated for 500 mW maximum power dissipation at 25°C ambient temperature, as stated in the Absolute Maximum Ratings table. Derating is required above 25°C at 1.47 mW/°C (1/RθJA), meaning usable power drops to ~300 mW at 85°C ambient-critical for thermal design validation when using the MMSZ5237B in enclosed or high-temperature environments.
How does the dynamic impedance of the MMSZ5237B affect circuit performance?
The MMSZ5237B has a maximum dynamic impedance (ZZ) of 8.0 Ω at 20 mA, directly determining output voltage stability under load changes. For example, a 1 mA load swing causes ≤8 mV variation-enabling accurate reference generation in ADC bias networks and low-drift shunt regulators where the MMSZ5237B serves as the core voltage-setting element.
Is the MMSZ5237B suitable for automotive applications?
No, the MMSZ5237B is not qualified for automotive use. Per Fairchild's Authorized Use policy in the datasheet, it is designated as a standard commercial product and explicitly excluded from automotive, safety-critical, or military/aerospace applications unless approved in writing by Fairchild. Engineers must select AEC-Q101 qualified Zeners for vehicle systems instead of the MMSZ5237B.
MMSZ5237B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 8.2 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 6 Ohms
- Current - Reverse Leakage @ Vr:
- -
- Voltage - Forward (Vf) (Max) @ If:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123
MMSZ5237B FAQ
1.How can I place an order for MMSZ5237B through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ5237B 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 MMSZ5237B reliable?
The price and inventory of MMSZ5237B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5237B is usually 5 days.
3.What payment methods are accepted for MMSZ5237B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5237B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ5237B?
MMSZ5237B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ5237B 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 MMSZ5237B?
For technical support, including MMSZ5237B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5237B requirements.
6.How does Aetrix verify that MMSZ5237B is sourced from the original manufacturer or authorized distributors?
All MMSZ5237B 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 MMSZ5237B meets industry standards.
7.What is the process for return or replacement of MMSZ5237B?
All MMSZ5237B units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5237B, 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 MMSZ5237B part is unused and in its original packaging.
Return procedure for MMSZ5237B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMSZ5237B Tags
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