Semtech Corporation 1N6158

Overview

1N6158 from Semtech is a transient diverting suppressor (TDS) designed for high-energy EOS protection of 22V DC power or I/O lines, featuring ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), 27.5–28V clamping voltage at 40A, 20mΩ dynamic resistance, and 175pF junction capacitance - deployed in USB PD, USB Type-C, and industrial load switch input protection.

For engineers reviewing the 1N6158 datasheet, pinout, applications, or equivalent options, this device delivers stable clamping across temperature (−40°C to +125°C) and current (24A–40A), enabling robust overvoltage protection where conventional TVS diodes exhibit rising clamping voltage with surge magnitude or ambient heat.

Technical Context

The 1N6158 uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that turns on the shunt path when transient voltage exceeds breakdown. Unlike standard TVS diodes, its clamping voltage remains nearly constant due to decreasing R_DS(on) under surge, not fixed dynamic resistance.

It operates as a single-line protector with bidirectional capability, rated for 22V reverse stand-off (VRWM), 25–27.9V breakdown (VBR), and 1120W peak pulse power. Its DFN 1.6×1.6×0.55mm package integrates three parallel input terminals (Pins 4–6) and three ground terminals (Pins 1–3) to minimize parasitic inductance and maximize surge current handling.

Key Specifications

Pinout & Package

Package: DFN 1.6 mm × 1.6 mm × 0.55 mm, 6-lead, Pb-free, RoHS-compliant, UL 94V-0 molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ22A and TPD2E001DRYR, the 1N6158 uniquely combines 40A surge capability, flat 27.5–28V clamping across temperature and current, and integrated multi-terminal layout - making it the only option qualified for 22V industrial power rail and USB PD front-end protection without derating or secondary components.

Availability

1N6158 is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial load switch inputs, and IoT device DC power rails requiring stable component supply, long-term lifecycle support, and guaranteed RoHS/WEEE compliance.

Supply support for 1N6158 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

Semtech Corporation is a U.S.-based fabless semiconductor company specializing in analog and mixed-signal ICs for precision sensing, protection, and signal integrity.

The 1N6158 belongs to Semtech's Transient Diverting Suppressor (TDS) family, engineered to replace conventional TVS diodes in high-reliability 22V power rail protection where stable clamping and temperature insensitivity are mandatory.

FAQ

What is the primary protection function of the 1N6158?

The 1N6158 functions as a transient diverting suppressor that shunts high-energy electrical overstress (EOS) events-such as ESD, lightning surges, and inductive switching spikes-to ground using an active FET-based architecture. Unlike passive TVS diodes, the 1N6158 maintains a near-constant clamping voltage of 27.5–28V across its full 40A surge rating and operating temperature range, ensuring predictable protection for sensitive 22V-rated ICs like USB PD controllers.

Does the 1N6158 require external bias or control signals to operate?

No, the 1N6158 is fully autonomous and requires no external power, enable signals, or configuration. Its internal precision trigger circuit detects overvoltage conditions above its 25–27.9V breakdown threshold and activates the shunt FET within nanoseconds. The 1N6158 draws only 130–600nA reverse leakage at 22V VRWM in normal operation, making it suitable for always-on power rail protection without impacting system quiescent current.

Can the 1N6158 be used on high-speed data lines such as USB 3.2 or PCIe?

No, the 1N6158 is not suitable for high-speed data lines due to its 175pF junction capacitance, which would severely degrade signal integrity above ~100MHz. It is specifically designed for DC power rails and low-speed I/O protection (e.g., USB-C VBUS, load switch inputs). For superspeed lanes, Semtech recommends pairing the 1N6158 with low-capacitance devices like RClamp3371ZC (<0.25pF) on TX/RX pairs.

How does the 1N6158's clamping performance compare to standard TVS diodes at elevated temperatures?

At 125°C, the 1N6158 maintains its 27.5–28V clamping voltage across 24–40A, whereas standard TVS diodes (e.g., SMAJ22A) exhibit significant clamping rise-often exceeding 40V at same conditions-due to positive temperature coefficient of dynamic resistance. This stability eliminates thermal derating and simplifies design validation for industrial and automotive applications where ambient temperature exceeds 85°C.

What PCB layout practices are critical for optimal 1N6158 performance?

For optimal 1N6158 performance, place the device within 2mm of the protected connector; connect all three IN pins (4–6) and all three GND pins (1–3) with short, wide traces; use ≥4 vias per GND pad to a solid ground plane; and avoid thermal relief on GND pads. These practices minimize parasitic inductance, ensuring the 1N6158 achieves its rated 40A surge capability and sub-10ns response to ESD events.