My Inquiry
My Account
onsemi MMSZ18ET1G
- Part No.:
- MMSZ18ET1G
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- SOD-123
- Datasheet:
-
MMSZ18ET1G.pdf
- Description:
- DIODE ZENER 18V 500MW SOD123
- Quantity:
- Payment:
- Shipping:
Inventory:22,558
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MMSZ18ET1G from onsemi is a 18 V, ±5% tolerance Zener diode in SOD-123 package, rated for 500 mW power dissipation at 75 °C on FR-5 board, with 45 Ω dynamic impedance at 5 mA test current and 0.05 µA reverse leakage at 12.6 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the MMSZ18ET1G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, AEC-Q101 qualification status, ESD robustness (Class 3, >16 kV HBM), and real-world substitution guidance for automotive and industrial power rail stabilization.
Technical Context
The MMSZ18ET1G operates as a two-terminal voltage reference device, conducting in reverse breakdown to clamp voltage across its terminals when reverse-biased above 17.1 V (min) and below 18.9 V (max) at IZT = 5 mA. Its junction-to-ambient thermal resistance is 340 °C/W, enabling stable operation up to +150 °C junction temperature.
It exhibits a positive temperature coefficient near 18 V nominal Zener voltage, with typical TC ≈ +3.5 mV/°C - confirmed by onsemi's published TC vs. VZ curve - and supports non-repetitive surge pulses up to 225 W (8 × 20 µs waveform), making it suitable for transient suppression in compact DC rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 17.1–18.9 V @ IZT = 5 mA; ensures ±5% regulation accuracy for 18 V reference design |
| Power Dissipation (PD) | 500 mW @ TL = 75 °C on FR-5; derates linearly to zero at 175 °C ambient (6.7 mW/°C) |
| Zener Impedance (ZZT) | 45 Ω max @ IZT = 5 mA; defines output impedance under regulation, critical for ripple rejection |
| Reverse Leakage (IR) | 0.05 µA max @ VR = 12.6 V; guarantees minimal standby current in battery-powered sensing nodes |
| ESD Rating | Class 3 (>16 kV) per HBM; eliminates need for external ESD protection in front-end voltage monitor inputs |
| AEC-Q101 Qualified | Validated for automotive-grade reliability; supports use in engine control modules and body electronics |
| Package | SOD-123 (1.60 × 2.69 × 1.16 mm); enables high-density placement on space-constrained PCBs |
Pinout & Package
SOD-123 surface-mount package with cathode indicated by polarity band; thermoset plastic case rated UL 94 V-0, Pb-free, and solderable at 260 °C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Banded End) | Cathode | Connected to regulated voltage rail; reverse-bias terminal where Zener breakdown occurs |
| 2 (Non-banded End) | Anode | Connected to ground or lower-potential node; completes current path during regulation |
Key Features
| Feature | Design Value |
|---|---|
| 500 mW Power Rating on FR-5 Board | Enables stable voltage clamping in 3.5 × 1.5 inch PCB layouts without forced air or heatsinking |
| Wide Zener Voltage Range (2.4–56 V) | Supports single-family sourcing across multiple rail voltages - e.g., MMSZ18ET1G for 18 V, MMSZ12ET1G for 12 V |
| ESD Robustness (Class 3, >16 kV HBM) | Eliminates need for discrete TVS in low-energy signal conditioning paths like sensor biasing |
| Automotive Qualification (AEC-Q101) | Validates performance across −55 °C to +150 °C operating range and lifetime stress testing for automotive ECUs |
| Small SOD-123 Footprint | Reduces board area by >40% vs. DO-35 through-hole Zeners, supporting miniaturized power management modules |
Applications
| Automotive Body Control Module | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Stabilizing 18 V supply rail for LIN transceiver ICs in door module electronics. IC Role / Device Role / Timing Role: Voltage reference and overvoltage clamp protecting LIN PHY input against load dump transients. Use Value: Maintains <18.9 V rail clamping during 225 W surge events while consuming only 0.05 µA quiescent leakage. |
Use Scenario: Providing precise 18 V bias to bridge amplifier stages in 4–20 mA loop-powered pressure sensors. IC Role / Device Role / Timing Role: Low-drift Zener reference ensuring <±0.5% output accuracy over −40 °C to +85 °C. Use Value: Delivers 45 Ω dynamic impedance to suppress ripple-induced gain error in analog front-end amplifiers. |
| Medical Portable Diagnostic Device | Consumer IoT Battery Management |
Use Scenario: Regulating auxiliary 18 V rail for optical sensor driver in handheld pulse oximeter. IC Role / Device Role / Timing Role: Low-leakage voltage clamp preventing overvoltage damage to CMOS image sensor interface. Use Value: Limits standby current to ≤0.05 µA, extending battery life in always-on monitoring mode. |
Use Scenario: Protecting USB-C PD negotiation circuitry from 18 V bus overvoltage in smart home hubs. IC Role / Device Role / Timing Role: Fast-response Zener shunt suppressing 8 × 20 µs surges before TVS activation. Use Value: Absorbs 225 W peak surge energy without degradation, preserving downstream USB controller integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BZX84-C18LT1G | Same 18 V nominal, but ±6% tolerance (vs. ±5%), higher ZZT = 50 Ω max, and 100 mW lower PD rating (400 mW) | Less precise regulation and reduced surge margin; suitable only for non-critical biasing | Select when cost sensitivity outweighs regulation accuracy and thermal headroom requirements |
| MMBZ5245BLT1G | 18 V nominal, ±5% tolerance, but TO-236 (SOT-23) package with 350 mW PD and 30 Ω ZZT; not AEC-Q101 qualified | Higher dynamic impedance stability but lacks automotive qualification and lower power handling | Prefer for commercial-grade designs needing tighter ZZT but no automotive compliance |
Compared with BZX84-C18LT1G and MMBZ5245BLT1G, the MMSZ18ET1G offers superior thermal capability (500 mW), tighter regulation (±5%), and AEC-Q101 validation - making it the optimal choice for automotive and industrial applications demanding long-term reliability under thermal stress.
Availability
MMSZ18ET1G is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor signal conditioning, medical portable diagnostics, and consumer IoT battery management requiring stable component supply and full traceability.
Supply support for MMSZ18ET1G 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, medical, and IoT applications.
The MMSZxxxET1G series targets high-reliability, surface-mount Zener regulation in space-constrained environments - designed specifically for automotive ECUs, industrial sensors, and portable medical devices requiring AEC-Q101 compliance and low-leakage performance.
FAQ
What is the Zener voltage tolerance of the MMSZ18ET1G?
The MMSZ18ET1G has a nominal Zener voltage of 18 V with a standard tolerance of ±5%, meaning its actual breakdown voltage falls between 17.1 V and 18.9 V when tested at IZT = 5 mA and TA = 25 °C. This tolerance is confirmed in the Electrical Characteristics table on page 2 of the onsemi datasheet revision 8.
Is the MMSZ18ET1G suitable for automotive applications?
Yes, the MMSZ18ET1G is AEC-Q101 qualified and PPAP capable, with validated operation across −55 °C to +150 °C junction temperature. Its SOD-123 package, 500 mW power rating, and Class 3 ESD rating make it appropriate for engine control units, body electronics, and ADAS subsystems where reliability under thermal and electrical stress is critical.
What is the maximum reverse leakage current for the MMSZ18ET1G?
The MMSZ18ET1G specifies a maximum reverse leakage current of 0.05 µA at VR = 12.6 V and TA = 25 °C. This ultra-low leakage supports battery-powered applications such as portable medical devices and wireless sensors where standby current must be minimized to extend operational life.
Does the MMSZ18ET1G have a defined thermal derating curve?
Yes, the MMSZ18ET1G derates linearly from 500 mW at TL = 75 °C to zero at approximately 175 °C ambient, with a slope of 6.7 mW/°C. This derating behavior is specified in the Maximum Ratings table and illustrated in Figure 3 ("Steady State Power Derating") of the onsemi datasheet.
What is the Zener impedance of the MMSZ18ET1G at 5 mA test current?
The MMSZ18ET1G has a maximum Zener impedance (ZZT) of 45 Ω at IZT = 5 mA and TA = 25 °C. This value reflects the device's small-signal AC resistance in regulation mode and directly impacts ripple rejection in voltage reference circuits - lower ZZT yields better noise suppression.
MMSZ18ET1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SOD-123
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 18 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 45 Ohms
- Current - Reverse Leakage @ Vr:
- 50 nA @ 12.6 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
MMSZ18ET1G FAQ
1.How can I place an order for MMSZ18ET1G through Aetrix?
Please submit a Request for Quotation (RFQ) for MMSZ18ET1G 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 MMSZ18ET1G reliable?
The price and inventory of MMSZ18ET1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMSZ18ET1G is usually 5 days.
3.What payment methods are accepted for MMSZ18ET1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMSZ18ET1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMSZ18ET1G?
MMSZ18ET1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMSZ18ET1G 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 MMSZ18ET1G?
For technical support, including MMSZ18ET1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMSZ18ET1G requirements.
6.How does Aetrix verify that MMSZ18ET1G is sourced from the original manufacturer or authorized distributors?
All MMSZ18ET1G 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 MMSZ18ET1G meets industry standards.
7.What is the process for return or replacement of MMSZ18ET1G?
All MMSZ18ET1G units undergo pre-shipment inspection (PSI). If there is an issue with MMSZ18ET1G, 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 MMSZ18ET1G part is unused and in its original packaging.
Return procedure for MMSZ18ET1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMSZ18ET1G Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
