onsemi MMQA6V2T1G

Overview

MMQA6V2T1G from onsemi is a quad monolithic common-anode ESD protection diode in SC-74 package, rated for 6.51 V nominal Zener voltage, 9.0 V clamping voltage at 2.66 A peak surge current, and 150 W peak power dissipation (20 µs waveform). It delivers Class 3B ESD protection (>16 kV HBM) with <700 nA reverse leakage at 4.0 V and 300 Ω max Zener impedance, used for I/O line protection in microprocessor interfaces and peripheral ports.

For engineers reviewing the MMQA6V2T1G datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, validated SC-74 terminal mapping, real-world use cases in bus-level transient suppression, and confirmed alternative parts for ESD-sensitive digital interface design.

Technical Context

This device implements four unidirectional Zener clamps sharing a common anode (pins 2 and 5), enabling independent protection of four signal lines with minimal PCB footprint. Its junction architecture supports simultaneous transient suppression across multiple I/O paths without cross-talk or shared cathode coupling.

Thermal performance is defined for FR-5 board (R_JA = 556 °C/W) and alumina substrate (R_JA = 417 °C/W), with steady-state power derating starting at 25 °C and pulse derating per Figure 4. The 24 W (1 ms) and 150 W (20 µs) peak power ratings reflect non-repetitive surge capability per standardized waveforms.

Key Specifications

Pinout & Package

SC-74 (Case 318F) surface-mount package with 6-pin leadframe, Pb-free finish, and void-free thermosetting plastic body optimized for automated assembly. Dimensions conform to standard SC-74 outline (2.2 mm × 2.2 mm × 1.0 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ESD protection applications.

Compared with ESDA6V1SC6 and TPD4E001DPYR, MMQA6V2T1G offers the lowest clamping voltage (9.0 V) among quad-package alternatives, tighter Zener tolerance (±4.5%), and proven compatibility with high-speed digital buses due to its sub-pF capacitance profile - making it optimal for noise-sensitive 3.3 V microcontroller interfaces.

Availability

MMQA6V2T1G is available at Aetrix Electronics and suitable for microprocessor bus protection, USB 2.0 interface hardening, industrial keypad shielding, and POS terminal serial port safeguarding requiring stable component supply across production lifecycles.

Supply support for MMQA6V2T1G 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

MMQA6V2T1G belongs to the MMQA Quad Common Anode Series - engineered specifically for space-constrained ESD protection of multi-line digital interfaces, balancing low clamping voltage, high surge robustness, and minimal parasitic capacitance.

FAQ

What is the exact Zener voltage tolerance for MMQA6V2T1G?

The MMQA6V2T1G has a specified Zener voltage range of 6.2 V (minimum) to 6.51 V (maximum) at 1.0 mA test current, corresponding to a ±4.5% tolerance around the nominal 6.51 V rating. This tight tolerance ensures consistent clamping behavior across production lots and temperature ranges from −55 °C to +150 °C, critical for reliable protection in precision 3.3 V logic systems.

Can MMQA6V2T1G be used for bidirectional transient suppression?

No, MMQA6V2T1G is strictly unidirectional - it conducts only when cathode voltage exceeds anode voltage by ≥6.2 V. For bidirectional protection (e.g., AC-coupled lines), two MMQA6V2T1G devices must be connected back-to-back, or a dedicated bidirectional TVS like SMAJ6.0A should be selected. The datasheet explicitly defines operation only for unidirectional configurations tied to pins 1/2/5, 2/3/5, 2/4/5, or 2/5/6.

What is the thermal resistance of MMQA6V2T1G on a standard FR-5 PCB?

When mounted on a standard FR-5 board (1.0 × 0.75 × 0.62 in.), MMQA6V2T1G exhibits a junction-to-ambient thermal resistance (R_JA) of 556 °C/W. This value assumes natural convection cooling and defines the steady-state power derating curve in Figure 3 - for example, at 75 °C ambient, maximum continuous power drops to approximately 125 mW based on the 225 mW rating at 25 °C.

How does the clamping voltage of MMQA6V2T1G compare to its Zener voltage?

MMQA6V2T1G clamps at 9.0 V when subjected to a 2.66 A peak pulse (20 µs waveform), which is 38% above its nominal Zener voltage of 6.51 V. This clamping ratio (V_RSM/V_ZT ≈ 1.38) is significantly tighter than many competing quad TVS diodes, minimizing overvoltage stress on downstream 3.3 V logic components during ESD events.

Is MMQA6V2T1G qualified for automotive applications?

While MMQA6V2T1G itself is not AEC-Q101 qualified, the SZMMQA6V2T1G variant (with SZ prefix) is fully AEC-Q101 qualified and PPAP capable. The base MMQA6V2T1G shares identical electrical and thermal specifications but lacks the automotive-specific process controls and traceability required for under-hood deployment. For automotive designs, engineers must specify SZMMQA6V2T1G instead.