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onsemi MMQA18VT1
- Part No.:
- MMQA18VT1
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SC-74, SOT-457
- Datasheet:
-
MMQA18VT1.pdf
- Description:
- TVS DIODE 14VWM 26VC SC74
- Quantity:
- Payment:
- Shipping:
Inventory:3,678
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Product details
Overview
MMQA18VT1 from ON Semiconductor is a quad monolithic common-anode ESD protection diode in SC−74 package, rated for 18 V nominal Zener voltage (17.1–18.9 V), 26 V clamping voltage at 1 A surge current, and 150 W peak pulse power (20 µs waveform). It delivers Class 3B ESD protection (>16 kV HBM) with <75 nA reverse leakage and 19 pF capacitance at 0 V - ideal for high-density I/O line protection in microprocessor interfaces.
For engineers reviewing the MMQA18VT1 datasheet, pinout, applications, or equivalent options, this device supports compact transient suppression across four independent unidirectional channels with verified thermal derating on FR-5 and alumina substrates, low-clamp performance under IEC 61000-4-2 surges, and automotive-grade AEC−Q101 qualification when ordered as SZMMQA18VT1.
Technical Context
This device implements a quad-junction common-anode silicon Zener structure optimized for unidirectional transient voltage suppression. Each of the four cathode-anode pairs operates independently with identical electrical specs, sharing only the anode terminals (pins 2 and 5) to minimize footprint.
It is characterized for two distinct surge waveforms: 10/1000 µs (24 W peak) and 8/20 µs (150 W peak), with clamping voltage defined at IRSM = 1 A per channel. Thermal resistance is 556 °C/W on FR-5 board and 417 °C/W on alumina substrate, enabling predictable power derating above 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 18 V (17.1–18.9 V range at 1 mA test current - sets precise overvoltage trip threshold) |
| Clamping Voltage | 26 V @ 1 A peak pulse (limits transient energy delivered to protected IC inputs) |
| Peak Pulse Power | 150 W @ 8/20 µs waveform (supports IEC 61000-4-5 Level 3 surge immunity) |
| ESD Rating | Class 3B (>16 kV HBM) - exceeds USB, HDMI, and RS-232 interface ESD requirements |
| Capacitance | 19 pF @ 0 V bias - preserves signal integrity on high-speed data lines up to ~200 MHz |
| Reverse Leakage | <75 nA @ 14 V - avoids DC loading on sensitive analog or reference nodes |
| Package | SC−74 (Case 318F) - 3.0 × 1.5 mm footprint with 6-pin leadframe for automated SMT assembly |
Pinout & Package
SC−74 package (Case 318F, Style 1) measures 3.0 × 1.5 × 1.0 mm with gull-wing leads. Anode terminals are shared (pins 2 and 5), enabling compact common-anode configuration across four independent cathode paths.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (Channel A) | Protected I/O line connection - clamps to common anode when voltage exceeds 18 V |
| 2 | Anode (Shared) | Common return path for all four channels - connects to system ground or supply rail |
| 3 | Cathode (Channel B) | Second independent protected line - electrically isolated but thermally coupled within die |
| 4 | Cathode (Channel C) | Third protected line - same Zener characteristics and clamping behavior as pins 1 and 3 |
| 5 | Anode (Shared) | Redundant anode terminal for improved current handling and layout flexibility |
| 6 | Cathode (Channel D) | Fourth protected line - enables full quad-line ESD protection in single 6-pin package |
Key Features
| Feature | Design Value |
|---|---|
| Quad common-anode architecture | Four independent unidirectional TVS paths share just two anode pins - reduces PCB area by >60% vs discrete diodes |
| 150 W 8/20 µs surge rating | Withstands repeated industrial-level transients without degradation - validated per IEC 61000-4-5 |
| 19 pF low capacitance | Minimizes signal distortion on USB 2.0, UART, and SPI lines - no need for series impedance tuning |
| AEC−Q101 qualified variant | SZMMQA18VT1 meets automotive temperature, reliability, and traceability requirements - suitable for infotainment I/O |
| Pb-free and RoHS compliant | Compatible with lead-free reflow profiles up to 260°C - supports modern manufacturing and environmental compliance |
Applications
| Microprocessor I/O Protection | USB Interface Protection |
|---|---|
Use Scenario: Protecting address/data/control buses between CPU and peripheral ICs in embedded controllers. IC Role / Device Role / Timing Role: Unidirectional transient suppressor on each bus line - clamps ESD events before they reach CMOS input stages. Use Value: Prevents latch-up and gate oxide damage during handling or cable hot-plug events while maintaining <19 pF loading on 10+ MHz signals. |
Use Scenario: Safeguarding D+ and D− lines of USB 2.0 ports against contact discharge in docking stations and peripherals. IC Role / Device Role / Timing Role: Low-capacitance TVS pair (pins 1&3 or 4&6) referenced to common ground - absorbs ±15 kV HBM without signal jitter. Use Value: Maintains USB eye diagram integrity and ensures full-speed (480 Mbps) compliance after repeated ESD stress. |
| Industrial Keypad Interface | Medical Sensor Front-End |
Use Scenario: Shielding matrix-scanned keypad lines in factory HMIs exposed to operator touch and static discharge. IC Role / Device Role / Timing Role: One MMQA18VT1 protects four row/column lines - common-anode tied to system ground, cathodes to each line. Use Value: Eliminates false keypresses and microcontroller resets caused by 8 kV air-gap discharges - validated per IEC 61000-4-2. |
Use Scenario: Guarding analog front-end inputs of patient-monitoring devices connected to ECG/SpO₂ sensors. IC Role / Device Role / Timing Role: Low-leakage (<75 nA) clamp on sensor signal paths - prevents DC offset shift while suppressing 15 kV ESD pulses. Use Value: Preserves sub-mV signal fidelity and avoids baseline drift during clinical use - critical for FDA 510(k) design validation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPD4E05U06DQAR | Lower clamping (12 V @ 1 A), lower capacitance (0.5 pF), dual-channel only - requires two devices for quad coverage | Better for high-speed USB 3.0/PCIe; insufficient surge margin for industrial 8/20 µs transients | Select when signal bandwidth >1 GHz and surge threat is limited to HBM only |
| SZMMQA15VT1G | 15 V nominal Zener (14.3–15.8 V), 21.7 V clamping - lower trip point but reduced headroom vs 3.3 V logic rails | Preferred for 3.3 V I/O systems where 18 V clamping risks overshoot into supply rail | Choose for tighter voltage margin on 3.3 V microcontrollers - verify VCC tolerance during clamping |
Compared with TPD4E05U06DQAR and SZMMQA15VT1G, MMQA18VT1 provides optimal balance of 18 V operating margin, 150 W surge capability, and quad integration for cost-sensitive 3.3 V/5 V embedded designs - especially where board space and BOM count are constrained.
Availability
MMQA18VT1 is available at Aetrix Electronics and suitable for microprocessor I/O protection, USB interface hardening, industrial keypad shielding, and medical sensor front-end designs requiring stable component supply and long-term lifecycle support.
Supply support for MMQA18VT1 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
ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensing, and protection solutions for automotive, industrial, and consumer markets.
The MMQA/SZMMQA series was engineered specifically for high-density, multi-line ESD suppression in space-constrained electronics - delivering quad-channel TVS performance in a single SC−74 package with AEC−Q101 readiness.
FAQ
What is the exact Zener voltage tolerance for MMQA18VT1?
The MMQA18VT1 has a guaranteed breakdown voltage range of 17.1 V to 18.9 V at 1.0 mA test current (IZT), with nominal value 18 V. This ±5% tolerance ensures reliable triggering above standard 3.3 V and 5 V logic rails while avoiding false trips during normal operation - confirmed per Table 1 of the October 2017 datasheet revision.
Does MMQA18VT1 support bidirectional transient suppression?
No, MMQA18VT1 is strictly unidirectional - it conducts only when cathode voltage exceeds anode voltage by ≥18 V. For bidirectional protection, two MMQA18VT1 devices must be used back-to-back, or a dedicated bidirectional array like SMBJ18A should be selected. The datasheet explicitly defines operation only for "unidirectional" configurations tied to pins 1/2/5, 2/3/5, etc.
How is thermal performance affected when using MMQA18VT1 on FR-5 versus alumina substrate?
On FR-5 board, MMQA18VT1 exhibits 556 °C/W junction-to-ambient thermal resistance and 225 mW steady-state power dissipation at 25°C; on alumina substrate, RJA drops to 417 °C/W with PD rising to 300 mW. Derating curves in Figures 3 and 4 show usable power falls to ~120 mW at 85°C ambient on FR-5, versus ~180 mW on alumina - critical for sustained surge duty cycles.
Can MMQA18VT1 replace discrete 18 V Zener diodes in existing designs?
Yes, MMQA18VT1 can replace four discrete 18 V Zeners with shared-cathode routing, provided the PCB layout accommodates its SC−74 pinout (anodes on pins 2 and 5, cathodes on 1/3/4/6). Its 19 pF capacitance and 26 V clamping match typical 1N5351A behavior, but layout must ensure low-inductance anode grounding to maintain specified surge response.
Is MMQA18VT1 suitable for automotive applications?
The base MMQA18VT1 is not automotive-qualified, but its SZMMQA18VT1 variant is AEC−Q101 certified and PPAP capable - featuring enhanced process controls, extended temperature screening (−55°C to +150°C), and traceable lot documentation. Use SZMMQA18VT1 for infotainment, body control, or ADAS I/O protection where automotive compliance is mandatory.
MMQA18VT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- SC-74, SOT-457
- Series:
- MMQA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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 (8/20µs)
- Power - Peak Pulse:
- 150W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-74
MMQA18VT1 FAQ
1.How can I place an order for MMQA18VT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for MMQA18VT1 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 MMQA18VT1 reliable?
The price and inventory of MMQA18VT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMQA18VT1 is usually 5 days.
3.What payment methods are accepted for MMQA18VT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMQA18VT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MMQA18VT1?
MMQA18VT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MMQA18VT1 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 MMQA18VT1?
For technical support, including MMQA18VT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMQA18VT1 requirements.
6.How does Aetrix verify that MMQA18VT1 is sourced from the original manufacturer or authorized distributors?
All MMQA18VT1 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 MMQA18VT1 meets industry standards.
7.What is the process for return or replacement of MMQA18VT1?
All MMQA18VT1 units undergo pre-shipment inspection (PSI). If there is an issue with MMQA18VT1, 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 MMQA18VT1 part is unused and in its original packaging.
Return procedure for MMQA18VT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MMQA18VT1 Tags
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