Microchip Technology SMDA15C-7/TR7

Overview

SMDA15C-7/TR7 from Microsemi (now Microchip Technology) is a bidirectional transient voltage suppressor (TVS) array in SO-8 package, designed for board-level ESD and surge protection of 7 I/O lines. It features 15 V standoff voltage (V_WM), 16.7 V minimum breakdown voltage (V_BR), 24 V clamping voltage at 1 A, 300 W peak pulse power (8/20 µs), and 70 pF line capacitance - ideal for protecting CMOS, TTL, and microprocessor I/O transceivers.

For engineers reviewing the SMDA15C-7/TR7 datasheet, SMDA15C-7/TR7 pinout, SMDA15C-7/TR7 application, or SMDA15C-7/TR7 equivalent, key selection criteria include V_WM ≥ circuit operating voltage, clamping performance under 1–5 A transients, IEC 61000-4-2/4-4 compliance, SO-8 footprint compatibility, and low-line capacitance for high-speed data interfaces.

Technical Context

This TVS array implements a monolithic silicon avalanche diode structure per channel, with all seven channels configured as bidirectional clamping devices sharing common cathode/anode reference nodes. Each line provides symmetrical clamping above ±16.7 V and holds below ±24 V at 1 A, enabling robust protection against ±15 kV contact ESD per IEC 61000-4-2.

Designed for surface-mount board-level integration, the device operates across –55°C to +150°C and maintains stable V_BR with +11 mV/°C temperature coefficient. Its 70 pF capacitance at 0 V and 1 MHz supports signal integrity on moderate-speed digital buses such as RS-232, RS-485, and parallel I/O without significant rise-time degradation.

Key Specifications

Pinout & Package

SO-8 surface-mount package (JEDEC MS-012AC), 4.9 mm × 6.0 mm body, 1.27 mm pitch, 1.75 mm max height. Pin #1 marked by dot on top surface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMDA12C-7/TR7, the SMDA15C-7/TR7 offers higher standoff for 12 V systems and lower clamping drift; versus SM712-TR, it delivers symmetrical protection with lower capacitance but less peak power - making it optimal for single-ended, space-constrained, 7-line I/O protection.

Availability

SMDA15C-7/TR7 is available at Aetrix Electronics and suitable for industrial serial interface protection, automotive body control module I/O, and embedded system parallel bus protection requiring stable component supply and long-term lifecycle support.

Supply support for SMDA15C-7/TR7 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

Microsemi (acquired by Microchip Technology in 2018) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.

The SMDAxxC-7 TVS array series was developed specifically for compact, multichannel board-level ESD and surge protection in space-constrained industrial and automotive electronics - emphasizing low capacitance, wide temperature range, and IEC-compliant transient handling.

FAQ

What is the standoff voltage (V_WM) of the SMDA15C-7/TR7, and why does it matter?

The SMDA15C-7/TR7 has a 15 V standoff voltage (V_WM), meaning it remains non-conductive up to this DC or continuous peak voltage. This value must exceed the maximum operating voltage of the protected line to prevent leakage or false triggering. For example, it's well-suited for 12 V automotive I/O or 5 V logic with margin, ensuring reliable clamping only during transients - a key design requirement confirmed in the MSC0888 datasheet for SMDA15C-7/TR7.

How many I/O lines does the SMDA15C-7/TR7 protect, and how are they arranged?

The SMDA15C-7/TR7 protects exactly seven bidirectional I/O lines using a single SO-8 package. Pins 1, 2, 3, 4, 6, 7, and 8 each serve as protected line terminals, while Pin 5 is the common cathode reference node. This configuration enables compact, coordinated protection of parallel buses or multi-signal interfaces without discrete part proliferation - a verified architecture shown in the MSC0888 circuit diagram for SMDA15C-7/TR7.

Does the SMDA15C-7/TR7 meet IEC 61000-4-2 and IEC 61000-4-4 standards?

Yes, the SMDA15C-7/TR7 is explicitly rated for compliance with IEC 61000-4-2 (ESD) and IEC 61000-4-4 (EFT) per its datasheet. It withstands ±15 kV contact discharge and 4 kV electrical fast transients - validated through standardized test waveforms. These ratings are intrinsic to the SMDA15C-7/TR7 device family and documented in the "Features" and "Application" sections of MSC0888.PDF.

What is the clamping voltage of the SMDA15C-7/TR7 at 5 A, and what does that imply for system protection?

The SMDA15C-7/TR7 clamps to a maximum of 30 V at 5 A (8/20 µs pulse), as specified in the Electrical Characteristics table. This defines the worst-case overvoltage imposed on downstream ICs during high-current transients - such as nearby lightning-induced surges. Since most 12 V-tolerant transceivers survive brief exposure to ≤30 V, this clamping level provides robust functional safety without requiring additional series impedance, a key performance parameter for SMDA15C-7/TR7 in industrial designs.

Is the SMDA15C-7/TR7 suitable for high-speed data lines like USB or HDMI?

No - the SMDA15C-7/TR7 is not recommended for USB 2.0, HDMI, or other >100 Mbps interfaces due to its 70 pF line capacitance, which causes unacceptable signal attenuation and jitter. It is optimized for moderate-speed applications (e.g., RS-232, RS-485, UART, parallel I/O) where capacitance <100 pF is acceptable. For high-speed lines, dedicated low-capacitance TVS arrays (e.g., <3 pF) should be used instead of SMDA15C-7/TR7.