onsemi SZSM24T1G

Overview

SZSM24T1G from onsemi is a dual common-anode ESD protection diode array in SOT-23 package, rated for 24 V working peak reverse voltage, 43 V clamping voltage at 1 A peak pulse current, and 300 W peak pulse power (8/20 µs). It delivers low leakage (≤1.0 µA), 60 pF typical capacitance at 0 V, and AEC-Q101 qualification for automotive interface protection.

For engineers reviewing the SZSM24T1G datasheet, pinout, applications, or equivalent options, key selection criteria include unidirectional dual-line surge clamping capability, SOT-23 footprint efficiency, automotive-grade reliability, and IEC 61000-4-2 ±26 kV contact ESD performance.

Technical Context

This device implements a monolithic dual-junction silicon transient voltage suppressor with shared anode (Pin 3) and separate cathodes (Pins 1 & 2), enabling independent protection of two signal lines. Its design supports both unidirectional configurations (e.g., data line to ground) and complies with IEC 61000-4-2, -4-4, and -4-5 immunity standards.

The SZSM24T1G operates across −55 °C to +150 °C junction temperature range, exhibits 556 °C/W thermal resistance on FR-5 board, and maintains stable breakdown voltage (26.7–31.35 V at 1 mA) with ≤0.1 %/°C temperature coefficient - critical for robustness in automotive infotainment and body control modules.

Key Specifications

Pinout & Package

SOT-23 (Case 318, Style 12) - 2.90 mm × 1.30 mm × 1.00 mm surface-mount package with void-free thermosetting plastic case, UL 94 V-0 flammability rating, and Pb-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SM24T1G and TPD2E001DRYR, the SZSM24T1G uniquely combines automotive qualification, 24 V operating margin, and dual-line SOT-23 integration - making it the only option qualified for safety-critical 12 V/24 V vehicle networks requiring zero-layout rework.

Availability

SZSM24T1G is available at Aetrix Electronics and suitable for automotive body electronics, industrial HMI systems, medical sensor interfaces, and USB 2.0 peripheral protection requiring stable component supply and long-term lifecycle support.

Supply support for SZSM24T1G 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 (Semiconductor Components Industries, LLC) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The SZSM24T1G belongs to the SM05T1G Series of ESD protection arrays, engineered specifically for space-constrained, high-reliability interfaces in automotive and industrial environments where dual-line transient suppression is required.

FAQ

What is the primary function of the SZSM24T1G in circuit protection?

The SZSM24T1G functions as a dual-channel unidirectional transient voltage suppressor, clamping voltage spikes on two independent signal lines to a common anode reference. It protects sensitive ICs from ESD, EFT, and lightning-induced surges by diverting transient current away from downstream circuitry - with verified 300 W peak power handling and ±26 kV IEC 61000-4-2 contact rating. The SZSM24T1G achieves this in a compact SOT-23 package without compromising leakage or capacitance.

Does the SZSM24T1G support bidirectional signal protection?

No, the SZSM24T1G is configured as a dual common-anode unidirectional device - meaning each cathode (Pins 1 and 2) conducts only when its associated signal line goes positive relative to the shared anode (Pin 3). It does not provide symmetrical clamping for AC or bidirectional buses like RS-485. For bidirectional protection, a separate dual-common-cathode device or back-to-back configuration would be required - the SZSM24T1G itself is not rated for reverse conduction beyond its specified VRWM of 24 V.

What is the maximum operating temperature range for the SZSM24T1G?

The SZSM24T1G is rated for a junction and storage temperature range of −55 °C to +150 °C, fully supporting under-hood automotive environments and industrial enclosures with minimal derating. At ambient temperatures above 25 °C, its power dissipation must be linearly derated by 1.8 mW/°C on FR-5 board - allowing sustained operation up to +125 °C ambient with appropriate thermal design. This wide range is validated per AEC-Q101 stress testing protocols.

How does the SZSM24T1G differ from the standard SM24T1G part number?

The SZSM24T1G differs from SM24T1G solely in its manufacturing traceability and qualification status: the "SZ" prefix denotes automotive-specific process controls, AEC-Q101 qualification, and PPAP capability - required for Tier 1 automotive supply chains. Electrically and physically, both share identical SOT-23 package, pinout, VRWM (24 V), VC (43 V), and 300 W surge rating. The SZSM24T1G is not a higher-performance variant - it is the same device with documented automotive compliance.

Can the SZSM24T1G be used to protect CAN bus lines?

Yes, the SZSM24T1G can protect CAN High and CAN Low lines in 12 V automotive networks, provided the common anode (Pin 3) is connected to ground and each cathode (Pins 1 & 2) ties to respective bus lines. Its 24 V VRWM exceeds typical CAN common-mode range (±36 V), and 43 V clamping ensures transceivers remain within safe operating area during ISO 7637-2 pulses. However, dedicated CAN TVS devices may offer tighter clamping or integrated filtering - the SZSM24T1G serves as a general-purpose, dual-line solution compatible with CAN FD physical layer requirements.