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

onsemi MMSZ56T1

Name: MMSZ56T1
Brand: onsemi
SKU: MMSZ56T1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMSZ56T1

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: MMSZ56T1.pdf

Description:: DIODE ZENER 56V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Inventory:9,219

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Product details

Overview

MMSZ56T1 from onsemi is a 56 V, ±5% tolerance Zener diode in SOD−123 package, rated for 500 mW power dissipation at 75°C on FR−5 board, with 200 Ω maximum dynamic impedance at 2 mA test current and 0.05 μA reverse leakage at 39.2 V, used for precision voltage regulation and overvoltage protection in power supply feedback loops.

For engineers reviewing the MMSZ56T1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, AEC−Q101 qualification status, and direct alternatives for automotive and industrial voltage reference designs.

Technical Context

The MMSZ56T1 operates as a two-terminal voltage reference device, conducting in reverse breakdown at nominal 56 V with ±5% tolerance, specified under 1 ms pulse width and 2 mA Zener test current (IZT1). Its temperature coefficient is +6.7 mV/°C near 56 V, placing it in the positive TC region of the Zener family.

Thermal design relies on R_JA = 340 °C/W and R_JL = 150 °C/W, with junction-to-ambient derating beginning above 75°C at 6.7 mW/°C. It meets Class 3 ESD (>16 kV HBM) and is AEC−Q101 qualified for automotive use.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	53.2–58.8 V at I_ZT = 2 mA; defines stable regulation point for feedback networks
Power Dissipation (P_D)	500 mW @ T_L = 75°C; usable up to 150°C with linear derating
Zener Impedance (Z_ZT)	200 Ω max @ I_ZT = 2 mA; impacts regulation stability under load transients
Reverse Leakage (I_R)	0.05 μA @ V_R = 39.2 V; ensures low standby current in high-impedance bias circuits
Package	SOD−123 (1.60 × 2.69 × 1.16 mm); surface-mount compatible with automated assembly
ESD Rating	Class 3 (>16 kV HBM); supports handling in standard manufacturing environments
AEC−Q101 Qualified	Yes; validated for automotive electronics including engine control and body modules

Pinout & Package

SOD−123 package with cathode indicated by polarity band; 2-terminal construction optimized for compact PCB layouts and high-density power regulation circuits.

Pin/Terminal	Circuit Role	Design Meaning
1 (Banded End)	Cathode	Connected to regulated output node in shunt configuration; accepts reverse bias for breakdown conduction
2 (Unbanded End)	Anode	Connected to ground or low-impedance return path; completes current loop during regulation

Key Features

Feature	Design Value
500 mW Power Rating on FR−5 Board	Enables robust voltage clamping in space-constrained DC/DC feedback paths without heatsinking
±5% Zener Voltage Tolerance	Supports tight regulation in precision reference applications without post-production trimming
AEC−Q101 Qualification	Validates reliability for automotive under-hood and infotainment systems operating across −55°C to +150°C
ESD Class 3 (>16 kV HBM)	Reduces risk of field failure due to handling or system-level ESD events in end equipment
Pb−Free SOD−123 Package	Complies with RoHS and ELV directives; compatible with lead-free reflow profiles up to 260°C

Applications

Automotive Engine Control Unit (ECU)	Industrial PLC Analog Input Protection
Use Scenario: Clamping reference voltage in microcontroller ADC bias circuitry exposed to load dump transients. IC Role / Device Role / Timing Role: Shunt voltage regulator providing stable 56 V reference for overvoltage detection threshold. Use Value: Prevents ADC saturation during 12 V system surges up to 40 V while maintaining <0.05 μA leakage at normal operating voltage.	Use Scenario: Protecting 24 V analog input channels from transient overvoltage in factory automation sensors. IC Role / Device Role / Timing Role: Standby-mode Zener clamp absorbing surge energy before front-end op-amp input stage. Use Value: Limits input voltage to ≤58.8 V with 200 Ω dynamic impedance, reducing required series resistance and preserving signal integrity.
Telecom Power Supply Feedback Loop	Medical Diagnostic Equipment Reference
Use Scenario: Setting precise output voltage in isolated flyback converter secondary-side regulation. IC Role / Device Role / Timing Role: Zener reference for optocoupler feedback network controlling primary-side PWM duty cycle. Use Value: Delivers 56 V reference with ±5% tolerance and +6.7 mV/°C TC, enabling <±2% output regulation over full temperature range.	Use Scenario: Providing stable bias voltage for high-gain amplifier stages in portable ultrasound signal chains. IC Role / Device Role / Timing Role: Low-leakage voltage reference stabilizing gain-setting resistors in analog front-end. Use Value: Ensures <0.05 μA leakage at 39.2 V, minimizing offset drift and preserving SNR in battery-powered diagnostic devices.

Automotive Engine Control Unit (ECU)

Industrial PLC Analog Input Protection

Use Scenario: Clamping reference voltage in microcontroller ADC bias circuitry exposed to load dump transients.

IC Role / Device Role / Timing Role: Shunt voltage regulator providing stable 56 V reference for overvoltage detection threshold.

Use Value: Prevents ADC saturation during 12 V system surges up to 40 V while maintaining <0.05 μA leakage at normal operating voltage.

Use Scenario: Protecting 24 V analog input channels from transient overvoltage in factory automation sensors.

IC Role / Device Role / Timing Role: Standby-mode Zener clamp absorbing surge energy before front-end op-amp input stage.

Use Value: Limits input voltage to ≤58.8 V with 200 Ω dynamic impedance, reducing required series resistance and preserving signal integrity.

Telecom Power Supply Feedback Loop

Medical Diagnostic Equipment Reference

Use Scenario: Setting precise output voltage in isolated flyback converter secondary-side regulation.

IC Role / Device Role / Timing Role: Zener reference for optocoupler feedback network controlling primary-side PWM duty cycle.

Use Value: Delivers 56 V reference with ±5% tolerance and +6.7 mV/°C TC, enabling <±2% output regulation over full temperature range.

Use Scenario: Providing stable bias voltage for high-gain amplifier stages in portable ultrasound signal chains.

IC Role / Device Role / Timing Role: Low-leakage voltage reference stabilizing gain-setting resistors in analog front-end.

Use Value: Ensures <0.05 μA leakage at 39.2 V, minimizing offset drift and preserving SNR in battery-powered diagnostic devices.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BZX584-C56	56 V, ±5%, 500 mW, SOD-123, but higher Z_ZT = 300 Ω @ 5 mA	Less stable under fast load transients; requires higher I_ZT for spec compliance	Acceptable where lower cost outweighs tighter impedance requirements
SZMMSZ56T1G	Identical electrical specs, AEC−Q101 qualified, same SOD−123 package, but with SZ prefix indicating automotive-specific traceability and PPAP support	Required for Tier 1 automotive BOMs needing full change control documentation	Drop-in replacement when automotive PPAP compliance is mandatory

Compared with BZX584-C56, MMSZ56T1 offers lower dynamic impedance and tighter test-current alignment; compared with SZMMSZ56T1G, it shares all electrical and thermal performance but lacks automotive-specific process controls and documentation traceability.

Availability

MMSZ56T1 is available at Aetrix Electronics and suitable for automotive ECU designs, industrial PLC analog protection, telecom power supply feedback loops, and medical diagnostic reference circuits requiring stable component supply with consistent parametric performance across production lots.

Supply support for MMSZ56T1 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, and consumer markets.

The MMSZxxxT1G series was designed specifically for high-reliability, surface-mount voltage regulation in space-constrained automotive and industrial power systems, emphasizing AEC−Q101 qualification and automated assembly compatibility.

FAQ

What is the Zener voltage tolerance for MMSZ56T1?

The MMSZ56T1 has a nominal Zener voltage of 56 V with a standard tolerance of ±5%, meaning the actual measured V_Z falls between 53.2 V and 58.8 V when tested at I_ZT = 2 mA and T_A = 25°C. This tolerance is guaranteed per the onsemi datasheet revision 13 and applies across the full operating temperature range.

Is MMSZ56T1 suitable for automotive applications?

Yes, MMSZ56T1 is AEC−Q101 qualified and PPAP capable, making it suitable for automotive applications such as engine control units, body electronics, and infotainment systems. It operates reliably from −55°C to +150°C and meets Class 3 ESD requirements (>16 kV HBM), fulfilling key automotive reliability criteria.

What is the maximum power dissipation of MMSZ56T1 at 100°C ambient?

At 100°C ambient, MMSZ56T1's power dissipation must be derated from its 500 mW rating at 75°C. With a derating factor of 6.7 mW/°C, the allowable P_D is 500 mW − (100 − 75) × 6.7 mW = 332.5 mW. This value assumes FR−5 board mounting and accounts for thermal resistance R_JA = 340 °C/W.

Does MMSZ56T1 have Pb−free packaging?

Yes, MMSZ56T1 is supplied in a Pb−free SOD−123 package compliant with RoHS and ELV directives. The "G" suffix in the ordering part number (e.g., MMSZ56T1G) explicitly denotes Pb−free construction, and the device supports standard lead-free reflow profiles with a maximum soldering temperature of 260°C for 10 seconds.

What is the reverse leakage current specification for MMSZ56T1?

MMSZ56T1 specifies a maximum reverse leakage current (I_R) of 0.05 μA at V_R = 39.2 V and T_A = 25°C. This ultra-low leakage ensures minimal parasitic current draw in high-impedance reference and bias networks, supporting precision analog designs where standby power and offset stability are critical.

MMSZ56T1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 56 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 200 Ohms

Current - Reverse Leakage @ Vr:: 50 nA @ 39.2 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

MMSZ56T1 FAQ

1.How can I place an order for MMSZ56T1 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMSZ56T1 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 MMSZ56T1 reliable?

The price and inventory of MMSZ56T1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ56T1 is usually 5 days.

3.What payment methods are accepted for MMSZ56T1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ56T1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMSZ56T1?

MMSZ56T1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMSZ56T1 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 MMSZ56T1?

For technical support, including MMSZ56T1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ56T1 requirements.

6.How does Aetrix verify that MMSZ56T1 is sourced from the original manufacturer or authorized distributors?

All MMSZ56T1 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 MMSZ56T1 meets industry standards.

7.What is the process for return or replacement of MMSZ56T1?

All MMSZ56T1 units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ56T1, 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 MMSZ56T1 part is unused and in its original packaging.

Return procedure for MMSZ56T1:

1.Submit a request within 90 days.

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

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