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onsemi SZMMBZ18VALT3G
- Part No.:
- SZMMBZ18VALT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SZMMBZ18VALT3G.pdf
- Description:
- TVS DIODE 14.5VWM 25VC SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,900
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Product details
Overview
SZMMBZ18VALT3G from onsemi is a dual common-anode Zener diode array in SOT-23 package, designed for transient overvoltage and ESD protection of two independent signal lines. It features 18 V nominal Zener breakdown voltage (±5%), 40 W peak pulse power at 1.0 ms, clamping voltage of 25 V at 1.6 A peak pulse current, and AEC-Q101 qualification for automotive use - deployed in CAN/LIN bus interfaces and microcontroller I/O protection.
For engineers reviewing the SZMMBZ18VALT3G datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional/unidirectional configuration flexibility, IEC 61000-4-2 Level 4 ±30 kV contact ESD rating, low leakage (<50 nA @ 14.5 V), and dual-line protection in space-constrained PCBs.
Technical Context
This device integrates two monolithic Zener junctions sharing a common anode (Pin 3), enabling either two separate unidirectional clamps (Pins 1–3 and 2–3) or one bidirectional clamp (Pins 1–2). Its 40 W peak power rating applies to each unidirectional path per Figure 6 waveform, with thermal resistance of 417 °C/W on alumina substrate.
The 18 V nominal breakdown voltage is specified at 1.0 mA test current with ±5% tolerance, temperature coefficient of +1.6 mV/°C, and maximum clamping voltage of 25 V at 1.6 A IPP - ensuring predictable voltage limiting during fast transients in automotive infotainment and body control modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 18 V nominal, 17.1–18.9 V range @ 1.0 mA - defines precise clamping threshold for 12 V system rail protection |
| Peak Pulse Power | 40 W @ 1.0 ms (unidirectional) - sustains high-energy ESD strikes without failure in automotive-grade environments |
| Clamping Voltage (VC) | 25 V @ IPP = 1.6 A - limits transient voltage to safe level for downstream 3.3 V/5 V logic interfaces |
| ESD Rating | IEC 61000-4-2 Level 4: ±30 kV contact discharge - meets stringent automotive ESD immunity requirements |
| Leakage Current | <50 nA @ VRWM = 14.5 V - ensures minimal standby power loss and signal integrity in always-on circuits |
| Package | SOT-23 (Case 318, Style 12) - enables 2.9 × 1.3 mm footprint for high-density routing in compact ECUs |
| AEC-Q101 Qualified | Validated for automotive applications including engine control, ADAS sensors, and infotainment head units |
Pinout & Package
SOT-23 package (Case 318, Style 12) with gull-wing leads; void-free thermosetting plastic case rated UL 94 V-0, 260 °C soldering tolerance for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode 1 | First unidirectional Zener cathode - connects to protected line 1 (e.g., CAN_H) |
| Pin 2 | Cathode 2 | Second unidirectional Zener cathode - connects to protected line 2 (e.g., CAN_L) |
| Pin 3 | Anode (common) | Shared anode tied to ground or reference plane - enables dual-line clamping with single return path |
Key Features
| Feature | Design Value |
|---|---|
| Dual common-anode topology | Protects two independent signal lines (e.g., differential bus pairs) using one SOT-23 footprint - saves >50% board area vs. discrete diodes |
| Bidirectional configuration capability | Pins 1 and 2 used as opposing cathodes with Pin 3 anode - forms symmetrical ±18 V clamping for AC-coupled data lines |
| Automotive-grade reliability | AEC-Q101 qualified, PPAP capable, and SZ-prefix designated for controlled manufacturing - supports Tier 1 automotive BOMs |
| High ESD robustness | Class 3B (>16 kV HBM), Class C (>400 V MM), and IEC 61000-4-2 Level 4 (±30 kV contact) - exceeds ISO 10605 requirements |
| Low capacitance design | Typical 150 pF @ 0 V bias (per junction) - minimizes signal distortion on high-speed buses like LIN or SENT |
Applications
| Automotive CAN Bus Protection | Microcontroller I/O Clamp |
|---|---|
|
Use Scenario: Protecting CAN_H and CAN_L lines in 12 V vehicle networks against load dump, jump-start surges, and ESD events. IC Role / Device Role / Timing Role: Dual-line transient voltage suppressor placed at connector interface before CAN transceiver. Use Value: Clamps transients to ≤25 V while maintaining <50 nA leakage - prevents transceiver latch-up and ensures ISO 11898-2 compliance. |
Use Scenario: Safeguarding GPIO, UART, and SPI pins of automotive MCUs (e.g., S32K series) against ESD during assembly and field operation. IC Role / Device Role / Timing Role: Low-capacitance Zener clamp between I/O pin and ground, leveraging common-anode architecture for dual-pin coverage. Use Value: Enables single-device protection of two adjacent MCU pins - reduces component count and eliminates routing crosstalk in tight QFP packages. |
| Infotainment Display Interface | Body Control Module Sensor Inputs |
|
Use Scenario: Shielding LVDS or FPD-Link II video data lanes from ESD in center-stack displays and digital instrument clusters. IC Role / Device Role / Timing Role: Bidirectional clamp formed by Pins 1–2 across differential pair, with Pin 3 grounded - provides symmetrical surge suppression. Use Value: 150 pF capacitance per junction avoids signal integrity degradation at 1+ Gbps data rates - maintains eye diagram margin per MIPI D-PHY v2.1. |
Use Scenario: Protecting analog sensor inputs (e.g., temperature, pressure) in BCMs from induced transients in 12 V chassis environments. IC Role / Device Role / Timing Role: Unidirectional Zener clamp (Pin 1–3 and Pin 2–3) on each sensor line, referenced to local ground plane. Use Value: 18 V breakdown matches typical 5 V ADC input ranges - prevents overvoltage damage while preserving 12-bit measurement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-Zener transient protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZMMBZ18VTALT3G | 2% Zener voltage tolerance (17.64–18.36 V) vs. 5% (17.1–18.9 V); identical package, power, and ESD ratings | Preferred for precision voltage clamping where tighter regulation is required, e.g., reference voltage rail protection | Select when ±2% VZ stability is critical; otherwise SZMMBZ18VALT3G offers cost-effective 5% tolerance for general-purpose line protection |
| SMF18AT1G | Single-channel TVS (SOD-123), 18 V VBR, 200 W peak power, but no dual-junction or common-anode capability | Requires two devices for dual-line protection; larger footprint and higher BOM count than SZMMBZ18VALT3G | Choose only if higher single-line surge rating is needed; SZMMBZ18VALT3G remains superior for space-constrained dual-line designs |
Compared with SZMMBZ18VTALT3G, the SZMMBZ18VALT3G trades tighter voltage tolerance for broader availability and lower cost in automotive production; versus SMF18AT1G, it delivers integrated dual-line protection with 60% smaller PCB area and simplified layout - making it optimal for CAN, LIN, and sensor interface applications.
Availability
SZMMBZ18VALT3G is available at Aetrix Electronics and suitable for automotive electronic control units, infotainment systems, and body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SZMMBZ18VALT3G 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications - focused on enabling safer, smarter, greener electronics.
The MMBZ/SZMMBZxxxALT1G series targets high-reliability transient suppression in space-constrained systems, with design emphasis on AEC-Q101 compliance, ultra-low leakage, and dual-line integration for modern vehicle architectures.
FAQ
What is the Zener breakdown voltage tolerance for SZMMBZ18VALT3G?
The SZMMBZ18VALT3G has a nominal Zener voltage of 18 V with a ±5% tolerance, meaning the actual breakdown voltage falls between 17.1 V and 18.9 V when measured at 1.0 mA test current. This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet, and applies to both unidirectional configurations (Pin 1–3 and Pin 2–3). The SZMMBZ18VALT3G is not rated for tighter tolerances - for ±2%, consider SZMMBZ18VTALT3G instead.
Can SZMMBZ18VALT3G be used in bidirectional ESD protection mode?
Yes, the SZMMBZ18VALT3G supports bidirectional operation by connecting Pins 1 and 2 to the differential signal pair (e.g., CAN_H and CAN_L) and grounding Pin 3 (common anode). This configuration creates symmetrical ±18 V clamping behavior, validated in onsemi's Typical Characteristics (Figure 1) and referenced in the "Typical Common Anode Applications" section (page 6). The SZMMBZ18VALT3G achieves this without external components, unlike discrete dual-diode solutions.
What is the maximum clamping voltage of SZMMBZ18VALT3G under surge conditions?
The maximum clamping voltage (VC) of SZMMBZ18VALT3G is 25 V at a peak pulse current (IPP) of 1.6 A, as specified in the 40 W electrical characteristics table on page 3 of the datasheet. This value is measured using the Figure 6 rectangular waveform and represents the upper limit of voltage seen by protected circuitry during a standardized 1.0 ms transient. The SZMMBZ18VALT3G maintains this clamping performance across −55 °C to +150 °C operating temperature.
Is SZMMBZ18VALT3G suitable for IEC 61000-4-2 Level 4 ESD testing?
Yes, the SZMMBZ18VALT3G is explicitly rated for IEC 61000-4-2 Level 4: ±30 kV contact discharge and ±20 kV air discharge, as stated in the Features section (page 1) and confirmed in the Electrical Characteristics summary. This rating exceeds standard automotive EMC requirements (e.g., ISO 10605) and makes the SZMMBZ18VALT3G appropriate for front-end protection in infotainment ports, diagnostic connectors, and sensor interfaces where direct user contact occurs.
What packaging option does SZMMBZ18VALT3G ship in?
The SZMMBZ18VALT3G ships in 13-inch tape-and-reel format containing 10,000 units per reel, as indicated in the Ordering Information table on page 2 of the datasheet (where "T3" suffix denotes the 10k reel). The device uses Pb-free (RoHS-compliant) SOT-23 packaging with corrosion-resistant, easily solderable finish and UL 94 V-0 flammability rating - compatible with standard automated pick-and-place and reflow processes.
SZMMBZ18VALT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 2
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 14.5V
- Voltage - Breakdown (Min):
- 17.1V
- Voltage - Clamping (Max) @ Ipp:
- 25V
- Current - Peak Pulse (10/1000µs):
- 1.6A
- Power - Peak Pulse:
- 40W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
SZMMBZ18VALT3G FAQ
1.How can I place an order for SZMMBZ18VALT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMBZ18VALT3G 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 SZMMBZ18VALT3G reliable?
The price and inventory of SZMMBZ18VALT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMBZ18VALT3G is usually 5 days.
3.What payment methods are accepted for SZMMBZ18VALT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMBZ18VALT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMBZ18VALT3G?
SZMMBZ18VALT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMBZ18VALT3G 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 SZMMBZ18VALT3G?
For technical support, including SZMMBZ18VALT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMBZ18VALT3G requirements.
6.How does Aetrix verify that SZMMBZ18VALT3G is sourced from the original manufacturer or authorized distributors?
All SZMMBZ18VALT3G 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 SZMMBZ18VALT3G meets industry standards.
7.What is the process for return or replacement of SZMMBZ18VALT3G?
All SZMMBZ18VALT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMBZ18VALT3G, 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 SZMMBZ18VALT3G part is unused and in its original packaging.
Return procedure for SZMMBZ18VALT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZMMBZ18VALT3G Tags
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