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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

onsemi MMSZ5230B

Name: MMSZ5230B
Brand: onsemi
SKU: MMSZ5230B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ5230B

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ5230B.pdf

Description:: DIODE ZENER 4.7V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:9,300

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Product details

Overview

MMSZ5230B from Fairchild Semiconductor is a 5.1 V, 500 mW surface-mount Zener diode in SOD-123 package, with 5% tolerance, 19 Ω dynamic impedance at 20 mA, and 2 µA reverse leakage at 3.8 V. It regulates voltage in low-power biasing, reference, and overvoltage protection circuits for industrial sensors and power supply feedback loops.

For engineers reviewing the MMSZ5230B datasheet, pinout, applications, or equivalent options, key selection criteria include its precise 5.1 V nominal Zener voltage, low 19 Ω impedance at test current, thermal resistance of 340 °C/W, and compatibility with standard SOD-123 PCB footprints in space-constrained designs.

Technical Context

The MMSZ5230B operates as a silicon planar Zener diode optimized for stable voltage reference generation in DC bias networks. Its 5.1 V breakdown is specified at I_Z = 20 mA with ±5% tolerance and exhibits temperature coefficient behavior typical of mid-voltage Zeners (≈+2 mV/°C near 25 °C).

It supports continuous operation up to +150 °C junction temperature and dissipates up to 500 mW at 25 °C ambient, derating linearly above that per 340 °C/W thermal resistance. Forward voltage is ≤0.9 V at 10 mA, enabling bidirectional clamping when used with series resistors.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage V_Z	4.465–4.935 V min–max at I_Z = 20 mA; ensures tight 5.1 V regulation in precision references.
Zener Impedance Z_Z	19 Ω max at I_Z = 20 mA; maintains low output variation under load transients.
Power Dissipation P_D	500 mW at T_A = 25 °C; defines maximum steady-state power in compact SOD-123 layout.
Reverse Leakage I_R	2.0 µA max at V_R = 3.8 V; minimizes quiescent current in battery-powered sensing nodes.
Forward Voltage V_F	≤0.9 V at I_F = 10 mA; enables use as bidirectional ESD clamp or polarity-insensitive shunt.
Package	SOD-123; industry-standard 2-pin surface-mount outline with 3.5 × 1.5 inch thermal pad recommendation.
Tolerance	±5%; aligns with general-purpose voltage reference requirements without trimming.

Pinout & Package

SOD-123 package: 2-terminal surface-mount device with cathode band marking; no internal leads-cathode and anode are exposed metalized pads on opposite ends of molded body.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Current entry terminal in forward bias	Connected to lower-potential node; enables forward conduction ≤0.9 V for clamping or detection.
Cathode	Current exit terminal in forward bias; Zener breakdown terminal	Marked end; connects to higher-potential node to enable 5.1 V reverse breakdown regulation.

Key Features

Feature	Design Value
Stable 5.1 V reference	Guaranteed 4.465–4.935 V range at 20 mA enables repeatable threshold setting in analog comparators.
Low dynamic impedance	19 Ω max improves regulation accuracy under varying load currents in feedback networks.
High-temperature operation	+150 °C max junction temperature supports deployment in automotive engine control modules and industrial PLCs.
SOD-123 footprint	Standardized 2.7 × 1.6 mm outline allows drop-in replacement and automated assembly compatibility.

Applications

Industrial Sensor Biasing	USB Port Overvoltage Clamp
Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) in factory-floor temperature monitors. IC Role / Device Role / Timing Role: Voltage reference diode establishing fixed 5.1 V bias point across RTD bridge. Use Value: 19 Ω Z_Z limits output drift to <10 mV under 1 mA load variation, improving measurement resolution.	Use Scenario: Protecting downstream USB data lines from transient surges during hot-plug events. IC Role / Device Role / Timing Role: Bidirectional shunt clamp using forward and reverse conduction paths. Use Value: ≤0.9 V forward drop and 5.1 V reverse breakdown jointly limit line voltage to safe levels below 5.5 V.
SMPS Feedback Reference	Microcontroller Reset Circuit
Use Scenario: Setting regulated output voltage in 5 V flyback converters for embedded power supplies. IC Role / Device Role / Timing Role: Precision Zener in optocoupler feedback loop to adjust PWM duty cycle. Use Value: ±5% V_Z tolerance directly translates to ±5% output voltage accuracy without secondary trimming.	Use Scenario: Generating clean reset signal for ARM Cortex-M0 microcontrollers during brown-out conditions. IC Role / Device Role / Timing Role: Threshold detector comparing supply rail against 5.1 V reference. Use Value: 2.0 µA max I_R at 3.8 V ensures negligible current draw in low-power sleep modes.

Industrial Sensor Biasing

USB Port Overvoltage Clamp

Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) in factory-floor temperature monitors.

IC Role / Device Role / Timing Role: Voltage reference diode establishing fixed 5.1 V bias point across RTD bridge.

Use Value: 19 Ω Z_Z limits output drift to <10 mV under 1 mA load variation, improving measurement resolution.

Use Scenario: Protecting downstream USB data lines from transient surges during hot-plug events.

IC Role / Device Role / Timing Role: Bidirectional shunt clamp using forward and reverse conduction paths.

Use Value: ≤0.9 V forward drop and 5.1 V reverse breakdown jointly limit line voltage to safe levels below 5.5 V.

SMPS Feedback Reference

Microcontroller Reset Circuit

Use Scenario: Setting regulated output voltage in 5 V flyback converters for embedded power supplies.

IC Role / Device Role / Timing Role: Precision Zener in optocoupler feedback loop to adjust PWM duty cycle.

Use Value: ±5% V_Z tolerance directly translates to ±5% output voltage accuracy without secondary trimming.

Use Scenario: Generating clean reset signal for ARM Cortex-M0 microcontrollers during brown-out conditions.

IC Role / Device Role / Timing Role: Threshold detector comparing supply rail against 5.1 V reference.

Use Value: 2.0 µA max I_R at 3.8 V ensures negligible current draw in low-power sleep modes.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX584C5V1	Same 5.1 V nominal, 5% tolerance, but SOD-323 package (smaller 1.7 × 1.3 mm); 20 Ω Z_Z.	Higher board density possible; lower power rating (300 mW vs. 500 mW) limits high-current reference use.	Select BZX584C5V1 only when PCB area is constrained and power dissipation remains <300 mW.
MM3Z5V1	Same 5.1 V, 5% tolerance, SOD-323, 300 mW rating; 40 Ω Z_Z - double MMSZ5230B's impedance.	Less stable regulation under load change; suitable for non-critical biasing where cost is prioritized.	Choose MM3Z5V1 for cost-sensitive consumer electronics where 40 Ω Z_Z does not impact system accuracy.

Compared with BZX584C5V1 and MM3Z5V1, the MMSZ5230B delivers superior regulation stability (19 Ω Z_Z) and higher power handling (500 mW), making it preferred for industrial feedback and sensor biasing where thermal margin and voltage accuracy are critical.

Availability

MMSZ5230B is available at Aetrix Electronics and suitable for industrial sensor biasing, USB port protection, SMPS feedback reference, and microcontroller reset circuits requiring stable component supply and long-term sourcing continuity.

Supply support for MMSZ5230B 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 MMSZ5230B belongs to the MMSZ52xxB Zener diode family designed for general-purpose voltage regulation and protection in space-limited, medium-power applications across industrial and consumer electronics.

FAQ

What is the nominal Zener voltage of the MMSZ5230B?

The MMSZ5230B has a nominal Zener voltage of 5.1 V, with a guaranteed range of 4.465 V to 4.935 V at test current I_Z = 20 mA. This value is specified at 25 °C ambient and reflects the device's primary function as a precision shunt voltage reference in analog and power circuits. The MMSZ5230B achieves this regulation via controlled avalanche breakdown in its silicon junction.

What is the maximum power dissipation rating for the MMSZ5230B?

The MMSZ5230B has a maximum power dissipation of 500 mW at 25 °C ambient temperature. Derating is required above this temperature at a rate determined by its 340 °C/W junction-to-ambient thermal resistance. This rating defines the upper limit of continuous DC power the MMSZ5230B can safely handle in SOD-123 mounting configurations with recommended PCB land patterns.

Does the MMSZ5230B have a specified forward voltage?

Yes, the MMSZ5230B specifies a maximum forward voltage of 0.9 V at forward current I_F = 10 mA. This parameter enables bidirectional use - as a Zener in reverse bias and as a low-drop diode in forward bias - supporting applications like dual-direction transient clamping and polarity-insensitive voltage limiting. The MMSZ5230B's forward characteristic is consistent across the full MMSZ5200 series.

What is the reverse leakage current specification for the MMSZ5230B?

The MMSZ5230B specifies a maximum reverse leakage current of 2.0 µA at reverse voltage V_R = 3.8 V and 25 °C. This low leakage supports energy-efficient operation in battery-powered systems and high-impedance reference networks where parasitic current must be minimized. The MMSZ5230B maintains this performance across its qualified operating temperature range.

Which package type does the MMSZ5230B use?

The MMSZ5230B uses the SOD-123 surface-mount package - a standardized 2-terminal plastic case measuring approximately 2.7 mm × 1.6 mm with cathode band marking. Its thermal design assumes a 3.5 × 1.5 inch FR-4 or FR-5 PCB with minimum recommended land pads, and the MMSZ5230B's 340 °C/W R_θJA is validated under those conditions.

MMSZ5230B Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 4.7 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 19 Ohms

Current - Reverse Leakage @ Vr:: 5 µA @ 2 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

MMSZ5230B FAQ

1.How can I place an order for MMSZ5230B through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ5230B 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 MMSZ5230B reliable?

The price and inventory of MMSZ5230B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ5230B is usually 5 days.

3.What payment methods are accepted for MMSZ5230B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ5230B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ5230B?

MMSZ5230B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ5230B 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 MMSZ5230B?

For technical support, including MMSZ5230B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ5230B requirements.

6.How does Aetrix verify that MMSZ5230B is sourced from the original manufacturer or authorized distributors?

All MMSZ5230B 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 MMSZ5230B meets industry standards.

7.What is the process for return or replacement of MMSZ5230B?

All MMSZ5230B units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ5230B, 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 MMSZ5230B part is unused and in its original packaging.

Return procedure for MMSZ5230B:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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