onsemi SL15T1

Overview

SL15T1 from onsemi is a unidirectional transient voltage suppression (TVS) diode in SOT-23 package, designed for ESD and surge protection of high-speed data lines. It delivers 300 W peak power (8 × 20 µs), clamps at 24 V @ 5 A, maintains ≤5 pF capacitance at 1 MHz, and supports IEC 61000-4-2 Level 4 (±16 kV air/±8 kV contact) compliance - deployed in USB 2.0, HDMI, and Ethernet PHY interfaces.

For engineers reviewing the SL15T1 datasheet, pinout, applications, or equivalent options, key selection criteria include working peak reverse voltage (15 V), low-junction-capacitance design (<5 pF), bi-directional protection capability via dual-device configuration, and Pb-free SOT-23 compatibility with automated assembly.

Technical Context

The SL15T1 implements a series-compensated TVS architecture: a primary avalanche diode is integrated with a forward-biased compensating diode to reduce effective junction capacitance below 5 pF. This topology enables signal integrity preservation on high-speed lines without sacrificing clamping performance.

It operates as a unidirectional device with cathode-anode-no-connect pinout (Pin 1 = cathode, Pin 2 = anode, Pin 3 = NC), requiring external inverse-parallel pairing for bidirectional protection. Thermal resistance is 556 °C/W on FR-5 board, supporting operation from –55 °C to +150 °C junction temperature.

Key Specifications

Pinout & Package

SOT-23 (TO-236, Case 318, Style 26) package with void-free thermosetting plastic body, UL 94 V-0 flammability rating, and Pb-free finish. Optimized for pick-and-place assembly and reflow soldering at 260 °C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TVS diode applications.

Compared with SMAJ15A and TPD2E001DRYR, the SL15T1 uniquely balances 15 V VRWM, ≤5 pF capacitance, and SOT-23 size - making it optimal for cost-sensitive, space-constrained 5 V high-speed interfaces requiring precise voltage clamping without signal degradation.

Availability

SL15T1 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, HDMI source port hardening, and industrial RS-485 transceiver safeguarding requiring stable component supply and RoHS-compliant sourcing.

Supply support for SL15T1 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The SL15T1 belongs to the SL05T1 Series of low-capacitance TVS diodes, engineered specifically to protect high-speed digital interfaces from ESD and transient surges while preserving signal fidelity.

FAQ

What is the working peak reverse voltage (VRWM) of the SL15T1?

The SL15T1 has a working peak reverse voltage (VRWM) of 15 V, meaning it remains in high-impedance state up to this DC or peak AC voltage level while leaking less than 1.0 µA. This rating ensures compatibility with standard 5 V and 3.3 V logic interfaces without false triggering during normal operation, and directly defines the maximum steady-state line voltage the SL15T1 can tolerate before entering breakdown.

How does the SL15T1 achieve its low 5 pF capacitance?

The SL15T1 achieves ≤5 pF junction capacitance by integrating a TVS diode in series with a compensating diode - exploiting the series capacitance formula (1/C_T = 1/C₁ + 1/C₂). This architecture reduces effective capacitance versus conventional single-diode TVS devices, enabling use on high-speed lines like USB 2.0 without degrading signal integrity. The SL15T1's measured capacitance is 3.5 pF typical at 0 V bias and 1 MHz.

Can the SL15T1 be used for bidirectional line protection?

The SL15T1 is a unidirectional TVS device and cannot provide bidirectional protection alone. To protect AC-coupled or truly bidirectional lines (e.g., HDMI TMDS), two SL15T1 units must be connected in inverse-parallel - one with anode-to-line/cathode-to-ground, the other with cathode-to-line/anode-to-ground. This configuration enables clamping for both positive and negative transients while retaining the SL15T1's low-capacitance advantage.

What is the maximum clamping voltage of the SL15T1 under surge conditions?

The SL15T1 clamps to a maximum of 24 V at 5 A peak pulse current (8 × 20 µs waveform), and 30 V at 10 A. This clamping voltage defines the upper voltage limit imposed on protected circuitry during transient events. For a 5 V system, this ensures downstream components experience no more than 24 V stress - well within safe margins for most 3.3 V or 5 V transceivers rated for 30 V absolute maximum.

Is the SL15T1 compatible with lead-free reflow soldering processes?

Yes, the SL15T1 is offered in Pb-free SOT-23 packaging and qualified for lead-free reflow soldering per JEDEC J-STD-020. Its maximum solder temperature rating is 260 °C for 10 seconds, matching standard Pb-free reflow profiles. The device marking "SL15T1G" explicitly denotes the Pb-free variant, and the thermosetting plastic case meets UL 94 V-0 flammability requirements for automated assembly environments.