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

onsemi SZMMSZ33T1G

Name: SZMMSZ33T1G
Brand: onsemi
SKU: SZMMSZ33T1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SZMMSZ33T1G

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: SOD-123

Datasheet:: SZMMSZ33T1G.pdf

Description:: DIODE ZENER 33V 500MW SOD123

Quantity:: RFQ Add To RFQ list

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Product details

Overview

SZMMSZ33T1G from onsemi is a 33 V ±5% Zener voltage regulator diode in SOD−123 surface-mount package, rated for 500 mW power dissipation at 75°C, with 80 Ω maximum dynamic impedance at 2 mA test current and 0.05 μA reverse leakage at 23.1 V. It serves as a precision voltage reference or overvoltage clamp in automotive power management circuits.

For engineers reviewing the SZMMSZ33T1G datasheet, pinout, applications, or equivalent options, key selection criteria include its AEC−Q101 qualification, ±5% Zener tolerance, 150°C junction temperature rating, and ESD robustness (>16 kV HBM), critical for under-hood automotive electronics and industrial sensor signal conditioning.

Technical Context

This device operates in reverse-biased Zener breakdown mode to maintain stable voltage regulation across load and line variations. Its 33 V nominal Zener voltage is specified at IZT = 2 mA with ±5% tolerance, and it exhibits a positive temperature coefficient above ~5.6 V-consistent with silicon Zener diodes in this voltage range.

The SOD−123 package enables high-density PCB layout while supporting automated assembly and delivering 150°C storage capability. Thermal resistance from junction-to-lead is 150°C/W, enabling reliable operation under transient surge conditions when mounted per JEDEC standards.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	31.35–34.65 V @ I_ZT = 2 mA - defines regulated output voltage window for reference or clamping
Power Dissipation (P_D)	500 mW @ T_L = 75°C - sets maximum continuous thermal load on FR-5 board
Zener Impedance (Z_ZT)	≤80 Ω @ I_ZT = 2 mA - determines regulation accuracy under varying load current
Reverse Leakage (I_R)	≤0.05 μA @ V_R = 23.1 V - ensures minimal standby current in voltage-sense circuits
Junction Temp Range	−55°C to +150°C - supports operation in automotive engine compartments and industrial enclosures
ESD Rating	Class 3 (>16 kV) HBM - protects against handling and assembly electrostatic discharge events
AEC-Q101 Qualified	Yes - validates reliability for automotive electronic control units and body electronics

Pinout & Package

SOD−123 plastic surface-mount package (1.60 × 2.69 × 1.16 mm), void-free thermosetting case with corrosion-resistant finish, cathode indicated by polarity band. Rated for 260°C soldering (10 s).

Pin/Terminal	Circuit Role	Design Meaning
1 (Cathode)	Zener anode connection point in reverse bias	Connected to regulated voltage node; polarity band identifies this terminal for correct orientation during placement
2 (Anode)	Zener cathode connection point in reverse bias	Connected to circuit ground or lower-potential rail; completes reverse-bias path for regulation

Key Features

Feature	Design Value
AEC−Q101 qualification	Validated for automotive-grade reliability including temperature cycling, humidity, and mechanical shock testing
±5% Zener voltage tolerance	Enables predictable clamping thresholds without post-production trimming in cost-sensitive designs
16 kV HBM ESD rating	Eliminates need for external ESD protection in low-energy interface nodes like sensor biasing or MCU reset lines
Pb−Free (RoHS-compliant) construction	Meets global environmental compliance requirements without sacrificing thermal or electrical performance
Small SOD−123 footprint	Supports >2× higher component density than legacy DO-35 or SMA packages in space-constrained modules

Applications

Automotive Engine Control Unit (ECU) Power Monitoring	Industrial Sensor Signal Conditioning
Use Scenario: Monitoring 12 V battery rail voltage in engine control modules to detect overvoltage faults before damaging microcontrollers. IC Role / Device Role / Timing Role: Zener clamp protecting ADC input of automotive-grade MCU from transients exceeding 33 V. Use Value: Prevents latch-up or damage during load-dump events while maintaining <0.05 μA leakage to avoid measurement offset errors.	Use Scenario: Providing stable 33 V reference for analog front-end amplifiers in pressure or temperature transducers. IC Role / Device Role / Timing Role: Precision voltage reference source for ratiometric sensor excitation and ADC reference scaling. Use Value: Delivers ±5% regulation stability over −40°C to +125°C ambient, matching sensor calibration ranges.
Telecom Base Station DC-DC Feedback Loop	Medical Diagnostic Equipment Overvoltage Protection
Use Scenario: Secondary-side voltage sensing in isolated 48 V telecom power supplies to regulate output via optocoupler feedback. IC Role / Device Role / Timing Role: Zener reference in TL431-like shunt regulator configuration for tight output tolerance. Use Value: 80 Ω dynamic impedance ensures <1% output deviation under 10–90% load steps at 33 V setpoint.	Use Scenario: Safeguarding analog acquisition circuits in portable ultrasound or ECG devices against accidental 36 V supply misconnection. IC Role / Device Role / Timing Role: Fast-acting overvoltage clamp on analog signal chain inputs prior to instrumentation amplifier stage. Use Value: Responds within nanoseconds to clamp surges >34.65 V while adding <1 pF capacitance to preserve signal integrity up to 10 MHz.

Automotive Engine Control Unit (ECU) Power Monitoring

Industrial Sensor Signal Conditioning

Use Scenario: Monitoring 12 V battery rail voltage in engine control modules to detect overvoltage faults before damaging microcontrollers.

IC Role / Device Role / Timing Role: Zener clamp protecting ADC input of automotive-grade MCU from transients exceeding 33 V.

Use Value: Prevents latch-up or damage during load-dump events while maintaining <0.05 μA leakage to avoid measurement offset errors.

Use Scenario: Providing stable 33 V reference for analog front-end amplifiers in pressure or temperature transducers.

IC Role / Device Role / Timing Role: Precision voltage reference source for ratiometric sensor excitation and ADC reference scaling.

Use Value: Delivers ±5% regulation stability over −40°C to +125°C ambient, matching sensor calibration ranges.

Telecom Base Station DC-DC Feedback Loop

Medical Diagnostic Equipment Overvoltage Protection

Use Scenario: Secondary-side voltage sensing in isolated 48 V telecom power supplies to regulate output via optocoupler feedback.

IC Role / Device Role / Timing Role: Zener reference in TL431-like shunt regulator configuration for tight output tolerance.

Use Value: 80 Ω dynamic impedance ensures <1% output deviation under 10–90% load steps at 33 V setpoint.

Use Scenario: Safeguarding analog acquisition circuits in portable ultrasound or ECG devices against accidental 36 V supply misconnection.

IC Role / Device Role / Timing Role: Fast-acting overvoltage clamp on analog signal chain inputs prior to instrumentation amplifier stage.

Use Value: Responds within nanoseconds to clamp surges >34.65 V while adding <1 pF capacitance to preserve signal integrity up to 10 MHz.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMSZ33T1G	No SZ prefix; not AEC−Q101 qualified; identical electrical specs and SOD−123 package	Intended for commercial/industrial use only; lacks automotive PPAP documentation support	Select when automotive qualification is unnecessary and cost sensitivity is higher
BZX84-C33	Higher Z_ZT (100 Ω max @ 5 mA); SOT-23 package; no AEC−Q101 qualification	Lower power rating (300 mW); less suitable for sustained 33 V clamping in high-temp environments	Choose for non-automotive, low-power consumer applications where board space allows SOT-23

Compared with MMSZ33T1G and BZX84-C33, SZMMSZ33T1G uniquely combines AEC−Q101 qualification, 500 mW power handling, and 33 V ±5% regulation in the compact SOD−123 footprint-making it the only option validated for under-hood automotive voltage supervision.

Availability

SZMMSZ33T1G is available at Aetrix Electronics and suitable for automotive power monitoring, industrial sensor reference design, and medical equipment overvoltage protection requiring stable component supply and long-term lifecycle assurance.

Supply support for SZMMSZ33T1G 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 (Semiconductor Components Industries, LLC) is a global semiconductor supplier focused on energy-efficient electronics for automotive, industrial, cloud, and IoT applications.

The SZMMSZxxxT1G series targets automotive-grade Zener regulation, designed specifically to meet AEC−Q101 stress test requirements while delivering precise voltage references in compact SOD−123 packaging.

FAQ

What is the Zener voltage tolerance for SZMMSZ33T1G?

The SZMMSZ33T1G has a nominal Zener voltage of 33 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 31.35 V and 34.65 V when tested at I_ZT = 2 mA and T_A = 25°C. This tolerance is guaranteed across the full operating temperature range and is part of the AEC−Q101 qualification scope for SZMMSZ33T1G.

Is SZMMSZ33T1G suitable for automotive applications?

Yes, SZMMSZ33T1G is AEC−Q101 qualified and PPAP capable, making it suitable for automotive applications including engine control units, body electronics, and ADAS power supervision. The "SZ" prefix denotes compliance with automotive-specific site and process controls, and its 150°C junction rating supports under-hood deployment where SZMMSZ33T1G operates reliably.

What is the maximum power dissipation of SZMMSZ33T1G?

SZMMSZ33T1G is rated for 500 mW total power dissipation on FR−5 board at lead temperature (T_L) = 75°C, derating linearly at 6.7 mW/°C above that temperature. Its thermal resistance junction-to-lead is 150°C/W, allowing SZMMSZ33T1G to sustain short-duration surges while maintaining safe junction temperatures in properly designed layouts.

Does SZMMSZ33T1G have ESD protection?

Yes, SZMMSZ33T1G features Class 3 ESD robustness (>16 kV) per Human Body Model, verified during AEC−Q101 qualification. This level of ESD immunity eliminates the need for additional protection components in many low-energy signal paths, enhancing system-level reliability without increasing bill-of-materials cost for SZMMSZ33T1G implementations.

What package type does SZMMSZ33T1G use?

SZMMSZ33T1G uses the SOD−123 surface-mount package (Case 425, Style 1), measuring 1.60 × 2.69 × 1.16 mm. It features a cathode polarity band and Pb−free construction, optimized for automated assembly and high-density PCB layouts. The SOD−123 footprint is standardized and compatible with common pick-and-place equipment used for SZMMSZ33T1G placement.

SZMMSZ33T1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SOD-123

Packaging:: Tape & Reel (TR)

Product Status:: Active

Voltage - Zener (Nom) (Vz):: 33 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 80 Ohms

Current - Reverse Leakage @ Vr:: 50 nA @ 23.1 V

Voltage - Forward (Vf) (Max) @ If:: 900 mV @ 10 mA

Operating Temperature:: -55°C ~ 150°C

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOD-123

SZMMSZ33T1G FAQ

1.How can I place an order for SZMMSZ33T1G through Aetrix?

Please submit a Request for Quotation (RFQ) for SZMMSZ33T1G 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 SZMMSZ33T1G reliable?

The price and inventory of SZMMSZ33T1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMSZ33T1G is usually 5 days.

3.What payment methods are accepted for SZMMSZ33T1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMSZ33T1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SZMMSZ33T1G?

SZMMSZ33T1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SZMMSZ33T1G 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 SZMMSZ33T1G?

For technical support, including SZMMSZ33T1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMSZ33T1G requirements.

6.How does Aetrix verify that SZMMSZ33T1G is sourced from the original manufacturer or authorized distributors?

All SZMMSZ33T1G 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 SZMMSZ33T1G meets industry standards.

7.What is the process for return or replacement of SZMMSZ33T1G?

All SZMMSZ33T1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMSZ33T1G, 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 SZMMSZ33T1G part is unused and in its original packaging.

Return procedure for SZMMSZ33T1G:

1.Submit a request within 90 days.

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

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