onsemi SZSL24T1G

Overview

SZSL24T1G from onsemi is a unidirectional ESD protection diode in SOT-23 package, designed for high-speed I/O line protection with 5.0 pF typical junction capacitance at 0 V, 24 V working peak reverse voltage (VRWM), and 300 W peak pulse power rating per 8 × 20 µs waveform - deployed in USB 2.0, HDMI, and Ethernet PHY interfaces.

For engineers reviewing the SZSL24T1G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage under 55 V at 5 A IPP, low leakage (<1.0 µA at VRWM), AEC-Q101 qualification for automotive use, and UL 94 V-0 flammability rating.

Technical Context

The SZSL24T1G implements a series-compensated diode architecture to achieve sub-5 pF capacitance by leveraging capacitive cancellation between surge and compensating diodes - enabling signal integrity preservation on >100 Mbps data lines. It operates as a unidirectional transient voltage suppressor with cathode-anode polarity and NC terminal.

Clamping behavior follows standardized IEC 61000-4-2 Level 4 (±8 kV contact, ±16 kV air) and IEC 61000-4-5 (12 A lightning surge) compliance. Thermal resistance is 556 °C/W on FR-5 board, limiting continuous power dissipation to 225 mW at 25 °C ambient.

Key Specifications

Pinout & Package

SOT-23 (TO-236) package, case 318, style 26 - surface-mount, void-free thermosetting plastic case with corrosion-resistant finish; optimized for automated placement and reflow soldering at 260 °C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ESD protection applications.

Compared with ESD5Z24 and TPD2E001DRYR, SZSL24T1G delivers higher pulse power (300 W vs. ≤150 W), lower capacitance (5.0 pF vs. ≥3.5 pF), and full automotive qualification - making it the only choice for AEC-Q101-compliant, high-speed, high-energy transient protection.

Availability

SZSL24T1G is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial communication gateways, and high-speed consumer interface designs requiring stable component supply and long-term lifecycle support.

Supply support for SZSL24T1G 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 focused on energy-efficient electronics, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.

SZSL24T1G belongs to the SL05T1G Series - a family of low-capacitance ESD protection diodes engineered specifically for high-speed data interfaces in automotive and industrial environments where signal fidelity and AEC-Q101 reliability are mandatory.

FAQ

What is the maximum clamping voltage of SZSL24T1G at 5 A transient current?

The SZSL24T1G has a maximum clamping voltage (VC) of 55 V at 5 A peak pulse current per the 8 × 20 µs waveform. This value is measured under standardized surge conditions and ensures protected downstream components remain within their absolute maximum voltage ratings during IEC 61000-4-2 and IEC 61000-4-5 events. The SZSL24T1G maintains this clamping performance across its full operating temperature range.

Is SZSL24T1G suitable for bidirectional signal lines like USB D+ and D−?

SZSL24T1G is a unidirectional device and must be used in pairs for bidirectional protection - one oriented with cathode toward the line, another with anode toward the line. For true bidirectional protection in a single package, consider alternatives such as the NUP4201MR6T1G. The SZSL24T1G's unidirectional architecture enables lower capacitance (5.0 pF) than most bidirectional equivalents.

Does SZSL24T1G require a heatsink in standard PCB layouts?

No, SZSL24T1G does not require a heatsink. Its thermal resistance junction-to-ambient is 556 °C/W on FR-5 board, and maximum continuous power dissipation is limited to 225 mW at 25 °C ambient. In typical ESD protection applications, energy is delivered in short pulses (≤20 µs), so thermal accumulation is negligible - standard 1 oz copper pour around pin 2 (anode) provides sufficient heat spreading for the SZSL24T1G.

What is the meaning of "SZ" prefix in SZSL24T1G?

The "SZ" prefix in SZSL24T1G indicates automotive-grade qualification: the device meets AEC-Q101 stress testing requirements and supports PPAP documentation. It also denotes unique site and process controls for automotive production traceability. Standard SL24T1G parts lack this prefix and are intended for commercial applications only - the SZSL24T1G is the only version qualified for automotive use.

Can SZSL24T1G be used on 3.3 V or 5 V logic lines?

No - SZSL24T1G is not recommended for 3.3 V or 5 V logic lines due to its 24 V working peak reverse voltage (VRWM). Using it on low-voltage lines risks excessive leakage current and potential false triggering. For 3.3 V interfaces, use SZESD9101F2T5G (VRWM = 3.3 V); for 5 V, use SZESD9102F2T5G (VRWM = 5.0 V). The SZSL24T1G is optimized for 12–24 V bus systems such as automotive Ethernet or industrial RS-485.