Semtech Corporation UCLAMP3612S.TCT

Overview

UCLAMP3612S.TCT from Semtech is a transient diverting suppressor (TDS) designed for high-energy EOS protection of 36V-rated power or I/O lines, featuring ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), 27.5V clamping at 24A, 20mΩ dynamic resistance, and DFN 1.6×1.6×0.55mm 6-lead package - deployed in USB PD input protection and industrial load switch front-end circuits.

For engineers reviewing the UCLAMP3612S.TCT datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage stability across temperature and current, low dynamic resistance for consistent surge handling, DFN footprint compatibility with high-density USB-C and IoT PCB layouts, and compliance with IEC 61000-4-2/4-4/4-5 standards.

Technical Context

The UCLAMP3612S.TCT 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 conventional TVS diodes, its clamping voltage remains nearly constant (27.5–28V) from 24A to 40A due to decreasing R_DS(on) under surge conditions.

It operates over −40°C to +125°C, maintains <600nA reverse leakage at 36V, exhibits 175pF junction capacitance at 22V bias, and delivers stable clamping independent of temperature - enabling reliable protection in thermally demanding industrial and mobile applications without derating.

Key Specifications

Pinout & Package

UCLAMP3612S.TCT is housed in a RoHS-compliant, halogen-free DFN package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no internal thermal pad required; energy dissipated in silicon). All six terminals are surface-mount; pins 1–3 are GND, pins 4–6 are IN - full parallel connection of each group is mandatory for rated 40A surge performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ36A and SP1003-36, UCLAMP3612S.TCT provides 30% lower clamping voltage at rated current, stable performance across temperature, and 2× higher surge current rating - making it the preferred choice for mission-critical 36V power rail protection where reliability and board space are constrained.

Availability

UCLAMP3612S.TCT is available at Aetrix Electronics and suitable for USB PD implementations, industrial load switch front-ends, and IoT edge node power rail protection requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for UCLAMP3612S.TCT 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 high-performance analog and mixed-signal ICs for precision protection, sensing, and signal integrity applications.

The UCLAMP series targets high-reliability transient suppression in next-generation power interfaces, emphasizing flat clamping, thermal stability, and ultra-small DFN packaging for space-constrained USB-C, industrial, and automotive subsystems.

FAQ

What is the maximum continuous operating voltage for UCLAMP3612S.TCT?

The UCLAMP3612S.TCT has a reverse stand-off voltage (V_RWM) of 36V, meaning it can reliably block up to 36V DC or RMS AC continuously without entering conduction. This makes UCLAMP3612S.TCT appropriate for 36V nominal power rails such as USB PD Extended Power Range (EPR) and industrial 24–36V systems, provided transient events remain within its 40A/1120W rating.

How does UCLAMP3612S.TCT achieve stable clamping voltage across temperature?

UCLAMP3612S.TCT achieves stable clamping by using a surge-rated FET as the conduction element, triggered by a precision circuit. As surge current increases, the FET's R_DS(on) decreases, counteracting voltage rise - resulting in clamping voltage of 27.5–28V from −40°C to +125°C. This behavior is confirmed in Figure 3 of the official Semtech datasheet for UCLAMP3612S.TCT.

Can UCLAMP3612S.TCT replace standard TVS diodes in existing 36V designs?

UCLAMP3612S.TCT can replace standard TVS diodes in 36V designs where improved clamping consistency, higher surge rating, or smaller footprint is needed - but layout changes are required: all three GND pins (1–3) and all three IN pins (4–6) must be shorted in parallel on PCB, unlike single-pin TVS devices. UCLAMP3612S.TCT is not a drop-in replacement; its DFN-6 layout and dual-group pinning demand updated land pattern and routing.

What is the junction capacitance of UCLAMP3612S.TCT and how does it affect circuit performance?

UCLAMP3612S.TCT exhibits 175pF junction capacitance at 22V reverse bias and 1MHz - verified in the Electrical Characteristics table of its datasheet. This value is low enough to avoid loading 36V power rails or slow analog signals, but too high for high-speed data lines (e.g., USB SS, PCIe). For those, UCLAMP3612S.TCT should be paired with sub-0.3pF devices like RClamp3371ZC on differential pairs.

Does UCLAMP3612S.TCT require a thermal pad or heatsink for 40A surge handling?

No, UCLAMP3612S.TCT does not require an external thermal pad or heatsink. Its energy dissipation occurs within the silicon die during transient events, and the DFN package is designed for short-duration, high-power pulses (e.g., 8/20μs). The datasheet explicitly states "no thermal pad is needed," and thermal performance is validated up to 40A under IEC 61000-4-5 conditions without derating.