Semtech Corporation UCLAMP1871P.TNT

Overview

UCLAMP1871P.TNT from Semtech is a transient diverting suppressor designed to protect 18V-rated I/O or power lines against EOS, ESD, and EFT events using a surge-rated FET shunt architecture. It delivers ±30kV IEC 61000-4-2 contact/air ESD protection, clamps at 25.5V (IPP = 24A), maintains <20mΩ dynamic resistance, and operates from –40°C to +125°C in a 1.6mm × 1.6mm DFN-6 package. It is deployed in USB Type-C PD input protection where stable clamping below controller damage thresholds is critical.

For engineers reviewing the UCLAMP1871P.TNT datasheet, pinout, applications, or equivalent options, key selection criteria include its constant clamping voltage across 24–40A surge currents, low 175pF junction capacitance at 22V, 22V working voltage compliance, thermal stability up to +125°C, and DFN-6 footprint compatibility with high-density USB PD and industrial load switch layouts.

Technical Context

The UCLAMP1871P.TNT uses a precision-triggered, surge-rated MOSFET as its primary protection element-unlike conventional TVS diodes-enabling near-constant clamping voltage independent of peak pulse current magnitude or temperature. Its trigger circuit activates the shunt FET when transient voltage exceeds breakdown, leveraging ultra-low R_DS(on) to limit V_C to ~25.5V across the full 24–40A I_PP range.

Electrical behavior is defined by three core parameters: 22V reverse stand-off voltage (V_RWM), 25–27.9V breakdown (V_BR at 1mA), and 27.5–28V clamping (V_C) under IEC 61000-4-5 combination waveforms. Dynamic resistance remains ≤20mΩ (measured 1–40A, 8/20μs), and leakage stays ≤600nA at V_RWM, ensuring minimal system loading during normal operation.

Key Specifications

Pinout & Package

UCLAMP1871P.TNT is housed in a RoHS-compliant, halogen-free DFN-6 package measuring 1.6mm × 1.6mm × 0.55mm with UL 94V-0 molding compound. All six terminals are surface-mount; no thermal pad required. Pin 1 is marked with a laser dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TDS2211P and SP1003-02HTG, UCLAMP1871P.TNT offers the optimal balance of 22V working voltage alignment, 28V clamping ceiling, and DFN-6 thermal/current robustness for USB PD and industrial 24V systems-without requiring PCB redesign or sacrificing surge margin.

Availability

UCLAMP1871P.TNT is available at Aetrix Electronics and suitable for USB Type-C power delivery interfaces, industrial load switch inputs, IoT device power rails, and storage device 12–24V bus protection requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for UCLAMP1871P.TNT 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 connectivity.

The UCLAMP series belongs to Semtech's transient protection product line, engineered specifically for high-reliability EOS suppression in power delivery, industrial automation, and high-speed interface applications where traditional TVS limitations in clamping stability and thermal drift are unacceptable.

FAQ

What is the maximum clamping voltage of UCLAMP1871P.TNT under a 40A IEC 61000-4-5 surge?

The UCLAMP1871P.TNT clamps at 27.5–28V when subjected to a 40A, 8/20μs peak pulse current per IEC 61000-4-5 with a 2Ω source impedance. This value is guaranteed across –40°C to +125°C and reflects its FET-based architecture's ability to maintain stable voltage limiting regardless of surge magnitude-unlike conventional TVS diodes whose clamping rises linearly with current.

Does UCLAMP1871P.TNT require a thermal pad on the PCB?

No, UCLAMP1871P.TNT does not require a thermal pad. Its DFN-6 package dissipates surge energy internally via the shunt FET, and the datasheet explicitly states "no thermal pad is needed." Instead, robust grounding through all three GND pins (1, 2, 3) with multiple vias to the ground plane is mandatory to minimize parasitic inductance and ensure full 40A surge capability.

Can UCLAMP1871P.TNT be used on USB-C superspeed differential pairs (TX/RX)?

No, UCLAMP1871P.TNT is not suitable for USB-C superspeed lanes. Its 175pF junction capacitance would severely degrade signal integrity at 10+ Gbps. Semtech recommends low-capacitance devices like RClamp3371ZC (<0.25pF) for SSTX/SSRX lines. UCLAMP1871P.TNT is intended for VBUS, CC, and SBU lines where capacitance tolerance is higher and voltage protection is primary.

How does UCLAMP1871P.TNT differ from standard TVS diodes in clamping behavior?

UCLAMP1871P.TNT uses a triggered FET shunt instead of a pn-junction, resulting in near-constant clamping voltage (27.5–28V) across 1–40A surge currents and –40°C to +125°C. Standard TVS diodes exhibit V_C = V_BR + I_PP × R_DYN, causing clamping to rise linearly with current and temperature-often exceeding safe limits for modern 24V-tolerant ICs.

Is UCLAMP1871P.TNT RoHS and halogen-free compliant?

Yes, UCLAMP1871P.TNT is fully RoHS/WEEE compliant and halogen-free, with lead-free terminal finish and UL 94V-0 flammability-rated molding compound. This compliance is confirmed in the mechanical characteristics section of the official Semtech datasheet and supports environmental requirements for industrial, medical, and consumer electronics deployments.