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onsemi SZMMBZH18VALT1G
- Part No.:
- SZMMBZH18VALT1G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SZMMBZH18VALT1G.pdf
- Description:
- TVS DIODE 14.5VWM 25VC SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,960
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Product details
Overview
SZMMBZH18VALT1G from onsemi is a dual common-anode SOT-23 Zener diode designed for ESD and transient overvoltage protection of two independent signal lines. It features a nominal 18 V breakdown voltage (VBR = 17.1–18.9 V @ IT = 1.0 mA), 40 W peak pulse power (1.0 ms), clamping voltage of 25 V at 1.6 A, and IEC61000-4-2 Level 4 (±30 kV contact) ESD rating - deployed in USB, HDMI, and industrial I/O interfaces.
For engineers reviewing the SZMMBZH18VALT1G datasheet, pinout, applications, or equivalent options, key selection criteria include unidirectional dual-line clamping capability, 175 °C junction temperature rating, AEC-Q101 qualification, and SOT-23 footprint compatibility with space-constrained PCB layouts.
Technical Context
This device implements a monolithic dual-junction Zener structure with shared anode (Pin 3), enabling independent cathode-to-anode clamping on Pins 1 and 2. Its 40 W peak power rating applies per line under unidirectional 1.0 ms surge (Figure 6 waveform), with thermal derating above 25 °C per Figure 7.
It delivers ±30 kV contact ESD protection per IEC61000-4-2 Level 4 and meets Class 3B HBM (>16 kV) and Class C MM (>400 V). The 14.5 V working peak reverse voltage (VRWM) ensures reliable standoff before conduction, while low leakage (<50 nA @ VRWM) minimizes standby current draw.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 17.1–18.9 V @ IT = 1.0 mA - defines precise clamping onset threshold for 18 V nominal rail protection |
| Working Peak Reverse Voltage (VRWM) | 14.5 V - maximum continuous reverse voltage before significant leakage or conduction begins |
| Clamping Voltage (VC) | 25 V @ IPP = 1.6 A - limits transient voltage seen by downstream ICs during 40 W surge events |
| Peak Pulse Power (Ppk) | 40 W @ 1.0 ms - sustains high-energy transients without failure, critical for industrial surge immunity |
| ESD Rating (IEC61000-4-2) | ±30 kV contact discharge - exceeds Level 4 requirement for robust system-level ESD compliance |
| Junction Temperature Range | −55 to +175 °C - supports operation in under-hood automotive and high-temperature industrial environments |
| AEC-Q101 Qualified | Yes - validated for automotive applications requiring PPAP documentation and process control traceability |
Pinout & Package
SOT-23 package (Case 318, Style 12), void-free thermosetting plastic body with UL 94 V-0 flammability rating and 260 °C soldering tolerance (10 s).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode 1 | First protected line - connects to signal path requiring clamping to common anode (Pin 3) |
| Pin 2 | Cathode 2 | Second protected line - enables dual-line ESD protection in single SOT-23 footprint |
| Pin 3 | Common Anode | Shared return node - ties both cathodes to ground or reference rail for bidirectional or unidirectional configuration |
Key Features
| Feature | Design Value |
|---|---|
| Dual common-anode Zener topology | Protects two independent signal lines (e.g., D+ and D−) using one SOT-23 package - reduces board area by 50% vs. discrete diodes |
| 40 W peak pulse power (unidirectional) | Withstands high-energy transients (e.g., ISO 7637-2 pulses) without degradation in automotive and industrial I/O ports |
| IEC61000-4-2 Level 4 ESD | Guarantees ±30 kV contact discharge immunity - eliminates need for external ESD suppressors in USB/HDMI designs |
| 175 °C TJ(MAX) | Enables placement near heat sources (e.g., power regulators) without thermal derating concerns in compact enclosures |
| AEC-Q101 qualification | Validates reliability for automotive infotainment, ADAS sensor interfaces, and body electronics with full PPAP support |
Applications
| USB 2.0 Data Line Protection | HDMI Interface ESD Suppression |
|---|---|
Use Scenario: Protecting D+ and D− differential pairs in portable USB peripherals against ESD events during hot-plug insertion. IC Role / Device Role / Timing Role: Dual-line transient voltage suppressor - clamps fast-rising ESD pulses before they reach the USB transceiver IC. Use Value: Prevents latch-up or permanent damage to USB PHYs while maintaining signal integrity up to 480 Mbps via low capacitance (<30 pF typical). | Use Scenario: Safeguarding HDMI TMDS channels (Clock, Data0–Data2) in set-top boxes and displays from user-handling ESD. IC Role / Device Role / Timing Role: Common-anode dual Zener array - provides matched clamping on parallel high-speed data lanes with shared ground reference. Use Value: Ensures HDMI compliance (CEC, HDCP handshaking) remains intact after ±30 kV contact discharge due to tight VBR tolerance (±5%). |
| Automotive CAN FD Transceiver Protection | Industrial RS-485 Port Surge Immunity |
Use Scenario: Shielding CAN_H and CAN_L lines in vehicle telematics modules from load-dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional dual Zener clamp - absorbs 40 W surges on each line independently while preserving CAN FD bit timing (up to 5 Mbps). Use Value: Maintains bus availability during 12 V/24 V system faults, meeting ISO 16750-2 pulse 5a requirements without adding series impedance. | Use Scenario: Hardening RS-485 transceivers in factory automation PLCs against lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: Dual-line TVS array - routes transient energy from A/B differential pair to chassis ground via common anode (Pin 3). Use Value: Enables 4 kV EFT (IEC61000-4-4) and 1 kV surge (IEC61000-4-5) immunity without degrading slew rate or common-mode rejection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-line Zener protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZMMBZH18VAT1G | Same electrical specs but non-AEC-Q101; lacks PPAP documentation and automotive change control | Restricted to commercial-grade systems without automotive qualification requirements | Select when cost sensitivity outweighs automotive compliance needs and no PPAP submission is required |
| TPD2E001DRYR | Lower Ppk (200 W total, 100 W per line); higher CJ (15 pF typical); integrated ESD-only design (no Zener regulation) | Optimized for ultra-low-capacitance high-speed data lines (e.g., USB 3.0), not power-rail clamping | Prefer for >1 Gbps interfaces where capacitance <0.5 pF per line is mandatory; avoid for 18 V rail protection |
Compared with SZMMBZH18VALT1G, SZMMBZH18VAT1G offers identical protection performance without automotive validation, while TPD2E001DRYR trades Zener regulation and surge handling for lower capacitance - making it suitable only for high-speed data, not power-supply or industrial surge scenarios.
Availability
SZMMBZH18VALT1G is available at Aetrix Electronics and suitable for USB interface protection, automotive CAN FD transceivers, and industrial RS-485 port hardening requiring stable component supply across production lifecycles.
Supply support for SZMMBZH18VALT1G 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 MMBZH/SZMMBZHxxxALT1G series was developed specifically for space-constrained, high-reliability ESD and surge protection in dual-signal-path systems - emphasizing AEC-Q101 qualification, 175 °C operation, and SOT-23 footprint efficiency.
FAQ
What is the clamping voltage of SZMMBZH18VALT1G at its rated peak pulse current?
The clamping voltage (VC) of SZMMBZH18VALT1G is 25 V at a peak pulse current (IPP) of 1.6 A, measured under the 1.0 ms rectangular waveform defined in Figure 6 of the datasheet. This value ensures downstream ICs see no more than 25 V during a 40 W transient event. The SZMMBZH18VALT1G maintains this clamping performance across its specified junction temperature range (−55 °C to +175 °C), with minor variation tracked in Figure 7's derating curve.
Is SZMMBZH18VALT1G suitable for bidirectional signal line protection?
Yes, SZMMBZH18VALT1G supports bidirectional protection when configured with external series resistors and appropriate biasing, though its native dual common-anode structure is optimized for unidirectional clamping (cathode-to-anode). For true bidirectional operation, two devices may be back-to-back; however, the SZMMBZH18VALT1G datasheet confirms its use in bidirectional ESD applications per IEC61000-4-2 testing. Its 14.5 V VRWM and symmetric Zener characteristics enable effective protection on AC-coupled lines.
Does SZMMBZH18VALT1G require a heatsink in standard FR-5 PCB layouts?
No, SZMMBZH18VALT1G does not require an external heatsink on standard FR-5 boards. Its thermal resistance junction-to-ambient (RJA) is 540 °C/W, and total power dissipation is rated at 225 mW at 25 °C ambient, derating linearly above that temperature. In typical ESD-protection use cases - which involve short-duration, non-repetitive pulses - steady-state heating is negligible. The SZMMBZH18VALT1G relies on PCB copper pour for thermal management, consistent with SOT-23 package design guidelines.
How does the AEC-Q101 qualification impact the manufacturing and traceability of SZMMBZH18VALT1G?
The AEC-Q101 qualification for SZMMBZH18VALT1G mandates strict process controls, lot-level traceability, extended reliability testing (including HTGB, TCT, and AC-H3TRB), and PPAP documentation. Each batch carries unique date and lot codes per the marking "ACJ" on the device body, and all materials meet automotive-grade material declarations (IMDS, REACH, RoHS). This ensures consistent performance in automotive applications where field failure is unacceptable - a requirement explicitly enforced for the SZ-prefix variant of the SZMMBZH18VALT1G.
Can SZMMBZH18VALT1G replace single-Zener diodes like 1N4746A in 18 V regulator applications?
No, SZMMBZH18VALT1G is not intended for voltage regulation or shunt regulator applications. It is engineered as a transient voltage suppressor with 40 W peak pulse capability and ESD hardening - not for continuous DC power dissipation. Its 225 mW steady-state power rating and SOT-23 thermal limits make it unsuitable for replacing through-hole Zeners like 1N4746A in linear regulator feedback paths. The SZMMBZH18VALT1G functions exclusively as a protective device, not a precision voltage reference or power-handling regulator.
SZMMBZH18VALT1G 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 ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
SZMMBZH18VALT1G FAQ
1.How can I place an order for SZMMBZH18VALT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMBZH18VALT1G 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 SZMMBZH18VALT1G reliable?
The price and inventory of SZMMBZH18VALT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMBZH18VALT1G is usually 5 days.
3.What payment methods are accepted for SZMMBZH18VALT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMBZH18VALT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMBZH18VALT1G?
SZMMBZH18VALT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMBZH18VALT1G 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 SZMMBZH18VALT1G?
For technical support, including SZMMBZH18VALT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMBZH18VALT1G requirements.
6.How does Aetrix verify that SZMMBZH18VALT1G is sourced from the original manufacturer or authorized distributors?
All SZMMBZH18VALT1G 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 SZMMBZH18VALT1G meets industry standards.
7.What is the process for return or replacement of SZMMBZH18VALT1G?
All SZMMBZH18VALT1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMBZH18VALT1G, 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 SZMMBZH18VALT1G part is unused and in its original packaging.
Return procedure for SZMMBZH18VALT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZMMBZH18VALT1G Tags
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ESD9B5.0ST5G
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D12V0L1B2LP-7B
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PESD2V0Y1BSFYL
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