Microchip Technology SM8LC05E3/TR7

Overview

SM8LC05E3/TR7 from Microsemi (now Microchip) is a bidirectional transient voltage suppressor (TVS) array in SO-8 package, rated for 500 W peak pulse power (8/20 µs), 5.0 V standoff voltage (V_WM), and 9.8 V breakdown voltage (V_BR @ 1 mA), providing board-level ESD protection per IEC 61000-4-2 to I/O transceivers and microprocessor interfaces.

For engineers reviewing the SM8LC05E3/TR7 datasheet, SM8LC05E3/TR7 pinout, SM8LC05E3/TR7 application, or SM8LC05E3/TR7 equivalent, key selection criteria include clamping voltage at 1 A (9.8 V), low line-to-line capacitance (25 pF), operating temperature range (–55 °C to +150 °C), and SO-8 surface-mount compatibility with standard I/O signal routing.

Technical Context

This TVS array integrates two independent, electrically isolated bidirectional suppression channels in a single SO-8 package, each configured as a back-to-back Zener diode pair. It delivers symmetric clamping for both positive and negative transients without polarity dependence.

Designed specifically for board-level surge immunity, it meets IEC 61000-4-2 (±15 kV contact discharge) and IEC 61000-4-4 (4 kV EFT), with leakage current ≤40 µA at 5.0 V and temperature coefficient of V_BR = +1 mV/°C - enabling stable threshold behavior across automotive and industrial temperature extremes.

Key Specifications

Pinout & Package

SO-8 surface-mount package (JEDEC MS-012AC), 5.0 mm × 4.0 mm footprint, 1.27 mm pitch, 1.75 mm max height; pin #1 identified by dot marking on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ5.0A and SP1003-050, the SM8LC05E3/TR7 uniquely combines dual-line bidirectional protection, 500 W surge rating, and SO-8 thermal pad in a single component - enabling compact, robust, and thermally efficient board-level I/O hardening for demanding industrial and automotive applications.

Availability

SM8LC05E3/TR7 is available at Aetrix Electronics and suitable for industrial HMIs, automotive body electronics, medical diagnostic ports, and point-of-sale serial interfaces requiring stable component supply and long-lifecycle support.

Supply support for SM8LC05E3/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-tolerant components for aerospace, defense, and industrial markets.

The SM8LCXX TVS array product line was developed to deliver standardized, high-surge-capacity board-level ESD protection for 3.3 V to 24 V digital interfaces - targeting automotive infotainment, industrial PLCs, and medical equipment with stringent IEC/EN compliance needs.

FAQ

What is the clamping voltage of SM8LC05E3/TR7 at 5 A, and why does it matter?

The SM8LC05E3/TR7 has a clamping voltage of 11 V at 5 A (per Figure 2 in MSC0333A.PDF). This value defines the maximum voltage imposed on protected circuitry during high-current transients like lightning-induced surges. Keeping this below the absolute maximum rating of downstream ICs - such as 5 V microcontrollers with 6.5 V abs max - prevents destructive overvoltage stress during real-world surge events.

Does SM8LC05E3/TR7 support bidirectional signal lines like RS-485 or CAN?

Yes, SM8LC05E3/TR7 supports bidirectional data lines including RS-485 and CAN due to its symmetrical Zener pair architecture per channel. Each channel clamps equally for positive and negative transients, preserving signal polarity integrity without DC biasing. Its 25 pF capacitance also ensures minimal impact on CAN FD's 2 Mbps timing margins.

How is thermal performance managed in SM8LC05E3/TR7 during repeated surge events?

SM8LC05E3/TR7 uses an exposed thermal pad (pins 5–8) soldered to a PCB ground plane to dissipate heat from surge energy. The SO-8 package's 1.75 mm max height and copper pad allow ≥70% of 500 W pulse energy to transfer into the board within milliseconds, preventing silicon junction overheating during repetitive 8/20 µs pulses at <0.01% duty cycle.

Can SM8LC05E3/TR7 replace SM8LC03E3/TR7 in a 3.3 V system?

No - SM8LC05E3/TR7 has a 5.0 V standoff voltage (V_WM) and is not suitable for 3.3 V systems where continuous operating voltage may approach or exceed V_WM. Using it risks premature conduction and excessive leakage. For 3.3 V rails, SM8LC03E3/TR7 (V_WM = 3.3 V) is the correct variant; both share identical SO-8 packaging and pinout.

What is the meaning of "E3/TR7" in SM8LC05E3/TR7?

"E3" denotes tape-and-reel packaging per EIA-481-1-A standard, and "TR7" specifies a 7-inch reel containing 2,500 units. This packaging format ensures automated pick-and-place compatibility and moisture-sensitive level (MSL) 1 handling - eliminating bake requirements prior to reflow soldering for the SM8LC05E3/TR7.