My Inquiry
My Account
onsemi SZMMQA18VT1G
- Part No.:
- SZMMQA18VT1G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SC-74, SOT-457
- Datasheet:
-
SZMMQA18VT1G.pdf
- Description:
- SURGE PROTECTOR, COMMON ANODE, S
- Quantity:
- Payment:
- Shipping:
Inventory:5,506
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SZMMQA18VT1G from onsemi is a quad monolithic common-anode ESD protection diode in SC-74 package, designed for transient overvoltage suppression on four independent signal lines. It features 18 V nominal Zener voltage (17.1–18.9 V), 26 V clamping voltage at 1 A peak pulse current, and 150 W peak power dissipation (20 µs waveform), targeting space-constrained I/O protection in microprocessor interfaces and communication ports.
For engineers reviewing the SZMMQA18VT1G datasheet, pinout, applications, or equivalent options, this device is evaluated for high-density PCB-level ESD hardening where low leakage (<75 nA), tight voltage tolerance, and multi-line common-anode topology are critical selection criteria.
Technical Context
The SZMMQA18VT1G integrates four unidirectional Zener junctions sharing a common anode (pins 2 and 5), enabling simultaneous protection of four signal paths with single-package footprint. Its design supports both 1.0 ms (24 W) and 20 µs (150 W) transient waveforms per IEC 61000-4-2 and ISO 10605 standards.
Thermal performance is characterized by 556 °C/W junction-to-ambient resistance on FR-5 board and −55 °C to +150 °C operating temperature range. The device meets AEC-Q101 qualification and Class 3B HBM ESD rating (>16 kV), confirming suitability for automotive and industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZT) | 17.1–18.9 V @ 1 mA - defines precise clamping threshold for 18 V rail protection |
| Clamping Voltage (VRSM) | 26 V @ 1 A peak pulse - limits transient-induced stress on downstream ICs |
| Peak Pulse Power | 150 W @ 20 µs - handles high-energy ESD events without failure |
| Reverse Leakage (IR) | <75 nA @ 14 V - ensures minimal signal loading and power loss in standby |
| ESD Rating (HBM) | Class 3B (>16 kV) - exceeds IEC 61000-4-2 Level 4 immunity requirements |
| Junction Temp Range | −55 °C to +150 °C - supports operation in under-hood automotive and industrial enclosures |
| Package | SC-74 (Case 318F) - 6-pin surface-mount footprint occupying 2.9 mm × 1.6 mm area |
Pinout & Package
SC-74 package (Case 318F, Style 1) is a 6-pin small-outline surface-mount package with void-free thermosetting plastic body and Pb-free finish. Pin 1 and Pin 3–4–6 are cathodes; Pins 2 and 5 are common anodes - enabling four independent unidirectional protection paths (e.g., pins 1–2–5, 2–3–5, 2–4–5, 2–5–6).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Cathode (Channel A) | Output node for first protected line; connects to I/O trace before clamp |
| Pin 2 | Common Anode | Shared return path to ground or supply rail for all four channels |
| Pin 3 | Cathode (Channel B) | Output node for second protected line; electrically isolated from other cathodes |
| Pin 4 | Cathode (Channel C) | Output node for third protected line; enables compact routing of parallel signals |
| Pin 5 | Common Anode | Redundant anode terminal for improved current sharing and thermal distribution |
| Pin 6 | Cathode (Channel D) | Output node for fourth protected line; completes quad-channel configuration |
Key Features
| Feature | Design Value |
|---|---|
| Quad Common-Anode Topology | Four independent unidirectional clamps share two anode terminals - reduces component count and PCB real estate by 75% vs discrete diodes |
| Low Clamping Ratio | VRSM/VZT ≈ 1.44 - delivers tighter voltage control during transients than standard TVS arrays |
| AEC-Q101 Qualified | Validated for automotive-grade reliability including temperature cycling, HTOL, and ESD stress - supports Tier-1 module designs |
| Pb-Free & RoHS Compliant | Meets JEDEC J-STD-020 reflow profile (260 °C peak) - compatible with lead-free SMT assembly without derating |
| High Surge Robustness | Withstands ≥125 A surge current (calculated from 26 V × 150 W / 26 V) - exceeds USB 2.0 and RS-485 surge test requirements |
Applications
| Microprocessor I/O Protection | USB 2.0 Port Protection |
|---|---|
|
Use Scenario: Protecting address/data/control buses between CPU and peripheral ICs against ESD and coupling transients. IC Role / Device Role / Timing Role: Unidirectional voltage clamp placed directly at connector or IC pad to limit overshoot/undershoot on bidirectional signals. Use Value: Prevents latch-up and gate oxide damage in 3.3 V/5 V logic interfaces while maintaining <75 nA leakage for low-power sleep modes. |
Use Scenario: Hardening D+ and D− lines of USB 2.0 upstream/downstream ports against contact discharge. IC Role / Device Role / Timing Role: Quad-channel ESD suppressor with shared anode tied to system ground - provides matched clamping for differential pair. Use Value: Achieves <26 V clamping at 1 A while preserving signal integrity up to 480 Mbps due to low 19 pF capacitance at 0 V bias. |
| Automotive Infotainment Display Interface | Industrial Serial Communication Line |
|
Use Scenario: Safeguarding LVDS or RGB parallel video lines from ESD events in center-stack displays. IC Role / Device Role / Timing Role: Common-anode array protecting four independent video data lanes with single-ground reference. Use Value: Enables compact layout near display connector; AEC-Q101 qualification ensures robustness across −40 °C to +105 °C ambient. |
Use Scenario: Protecting RS-485/RS-422 driver/receiver pairs in factory automation controllers. IC Role / Device Role / Timing Role: Four-channel clamp applied to A/B/Y/Z differential lines - common anode connected to local ground plane. Use Value: Handles 150 W surges per line without degradation; 26 V clamping prevents receiver input saturation during 4 kV contact discharge. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZMMQA15VT1G | 15 V nominal Zener voltage (14.3–15.8 V), 21.7 V clamping at 1 A | Better suited for 3.3 V or 5 V logic rails; lower clamping margin than SZMMQA18VT1G | Select when protecting lower-voltage interfaces where tighter VZ tolerance is required |
| SZMMQA24VT1G | 24 V nominal Zener voltage (22.8–25.2 V), 34.6 V clamping at 1 A | Higher clamping threshold; intended for 12 V or 24 V systems with larger voltage margins | Choose for industrial sensors or CAN transceivers requiring higher standoff voltage |
Compared with SZMMQA15VT1G and SZMMQA24VT1G, the SZMMQA18VT1G offers optimal clamping headroom for 12 V supply domains - balancing protection margin against false triggering in mixed-signal embedded systems.
Availability
SZMMQA18VT1G is available at Aetrix Electronics and suitable for automotive infotainment modules, industrial serial communication nodes, and USB 2.0 peripheral designs requiring stable component supply and long-term lifecycle support.
Supply support for SZMMQA18VT1G 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 (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.
The SZMMQA series belongs to onsemi's ESD protection portfolio, engineered specifically for high-density, multi-line transient suppression in space-constrained PCBs with AEC-Q101 compliance.
FAQ
What is the exact Zener voltage tolerance for SZMMQA18VT1G?
The SZMMQA18VT1G has a guaranteed breakdown voltage range of 17.1 V to 18.9 V at 1 mA test current, with nominal value of 18 V. This ±5% tolerance is specified per the onsemi datasheet Rev. 13 and applies under TA = 25 °C conditions. The SZMMQA18VT1G maintains this specification across its qualified operating temperature range.
Is SZMMQA18VT1G pin-compatible with other devices in the MMQA/SZMMQA family?
Yes, all SC-74 packaged MMQA and SZMMQA devices - including SZMMQA18VT1G - share identical pinout (Style 1: cathodes on pins 1/3/4/6, common anodes on pins 2/5). Mechanical and electrical compatibility is maintained across the series, allowing direct substitution when voltage ratings align with system requirements.
Does SZMMQA18VT1G support bidirectional ESD protection?
No, SZMMQA18VT1G is strictly unidirectional. Its common-anode architecture requires the anode terminals (pins 2 and 5) to be connected to ground or a positive rail, with cathodes (pins 1/3/4/6) tied to protected signal lines. For bidirectional protection, separate back-to-back configurations or dedicated bidirectional arrays must be used.
What is the maximum allowable reverse leakage current for SZMMQA18VT1G at 14 V?
The maximum reverse leakage current for SZMMQA18VT1G is 75 nA at VR = 14 V and TA = 25 °C, as confirmed in the Electrical Characteristics table on page 2 of the datasheet. This low leakage ensures minimal impact on high-impedance sensor inputs or battery-powered circuits where quiescent current matters.
How does the thermal resistance of SZMMQA18VT1G compare between FR-5 and alumina substrates?
SZMMQA18VT1G exhibits RJA = 556 °C/W on FR-5 board and RJA = 417 °C/W on 99.5% alumina substrate (0.4 × 0.3 × 0.024 in.), per Thermal Characteristics table. This 25% improvement reflects superior heat spreading on ceramic, enabling higher sustained power handling in thermally demanding applications using the SZMMQA18VT1G.
SZMMQA18VT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- SC-74, SOT-457
- Series:
- SZMMQA
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 4
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 14V (Max)
- Voltage - Breakdown (Min):
- 17.1V
- Voltage - Clamping (Max) @ Ipp:
- 26V
- Current - Peak Pulse (10/1000µs):
- 923mA
- Power - Peak Pulse:
- 150W
- 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:
- SC-74
SZMMQA18VT1G FAQ
1.How can I place an order for SZMMQA18VT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZMMQA18VT1G 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 SZMMQA18VT1G reliable?
The price and inventory of SZMMQA18VT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZMMQA18VT1G is usually 5 days.
3.What payment methods are accepted for SZMMQA18VT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZMMQA18VT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZMMQA18VT1G?
SZMMQA18VT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZMMQA18VT1G 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 SZMMQA18VT1G?
For technical support, including SZMMQA18VT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZMMQA18VT1G requirements.
6.How does Aetrix verify that SZMMQA18VT1G is sourced from the original manufacturer or authorized distributors?
All SZMMQA18VT1G 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 SZMMQA18VT1G meets industry standards.
7.What is the process for return or replacement of SZMMQA18VT1G?
All SZMMQA18VT1G units undergo pre-shipment inspection (PSI). If there is an issue with SZMMQA18VT1G, 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 SZMMQA18VT1G part is unused and in its original packaging.
Return procedure for SZMMQA18VT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZMMQA18VT1G Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
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…
