onsemi SZNUP3105LT1G

Overview

SZNUP3105LT1G from onsemi is a dual-line bidirectional ESD protection diode in SOT-23 package, designed specifically for CAN bus transceiver protection in 24 V automotive and industrial systems. It delivers 350 W peak power dissipation per line (8/20 µs), clamps at ≤59 V @ 5 A, and exhibits ≤30 pF line-to-ground capacitance to preserve high-speed CAN signal integrity.

For engineers reviewing the SZNUP3105LT1G datasheet, pinout, applications, or equivalent options, key selection criteria include IEC 61000-4-2 Level 4 ESD immunity (±30 kV contact), AEC-Q101 qualification, low leakage (<100 nA @ 32 V), and compact SOT-23 footprint for space-constrained CAN nodes.

Technical Context

The SZNUP3105LT1G integrates two identical bidirectional Zener-based surge protection elements in a single SOT-23 package, enabling simultaneous protection of CAN_H and CAN_L lines without external components. Its clamping behavior relies on reverse-biased breakdown (V_BR = 35.6 V) plus forward diode drop, achieving VC ≤ 59 V at IPP = 5 A.

It meets stringent transient immunity standards: IEC 61000-4-4 (50 A EFT), IEC 61000-4-5 (8.0 A lightning surge), and supports operation across −55 °C to +150 °C junction temperature range - essential for under-hood automotive CAN networks and industrial control environments.

Key Specifications

Pinout & Package

SZNUP3105LT1G uses the SOT-23 (TO-236) package (2.90 × 1.30 × 1.00 mm, 1.90 mm pitch), case 318, style 27 - confirmed as dual-cathode configuration per marking diagram and mechanical outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPD2E001DRYR and SM712-TP, the SZNUP3105LT1G uniquely balances CAN-optimized 30 pF capacitance, 350 W surge capability, AEC-Q101 qualification, and SOT-23 footprint - making it the only drop-in solution for production automotive and industrial CAN nodes requiring all four attributes.

Availability

SZNUP3105LT1G is available at Aetrix Electronics and suitable for automotive ECU design, industrial CAN gateway development, and heavy-duty vehicle telematics requiring stable component supply and long-term lifecycle support.

Supply support for SZNUP3105LT1G 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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The SZNUP3105LT1G belongs to onsemi's transient voltage suppression portfolio, engineered specifically for CAN bus protection in harsh 24 V environments - emphasizing reliability, AEC-Q101 compliance, and minimal signal degradation.

FAQ

What is the primary function of the SZNUP3105LT1G in a CAN network?

The SZNUP3105LT1G serves as a dual-line bidirectional ESD and transient voltage suppressor for CAN_H and CAN_L signals. It clamps voltage spikes - such as those from ESD events, EFT bursts, or lightning-induced surges - to protect downstream CAN transceivers. Its design ensures signal integrity is preserved via low 30 pF capacitance while meeting IEC 61000-4-2 Level 4 and AEC-Q101 requirements. The SZNUP3105LT1G is not a transceiver or controller but a dedicated protection device placed at the physical interface.

Is the SZNUP3105LT1G pin-compatible with other dual-line CAN protectors like the NUP2105L?

No, the SZNUP3105LT1G is not pin-compatible with the NUP2105L. While both are dual-line CAN protectors in SOT-23 packages, the SZNUP3105LT1G uses Style 27 (dual cathode, common cathode on Pin 3), whereas the NUP2105L follows Style 12 (dual anode, common anode on Pin 3). This reversal changes the required PCB layout and grounding scheme. The SZNUP3105LT1G must be used with its specified pinout - Pin 1 and Pin 2 as cathodes for CAN_H and CAN_L, Pin 3 as shared cathode to ground - to ensure correct clamping polarity.

Does the SZNUP3105LT1G support both high-speed and fault-tolerant CAN protocols?

Yes, the SZNUP3105LT1G supports both high-speed CAN (ISO 11898-2, up to 1 Mbps) and fault-tolerant CAN (ISO 11898-3) due to its 30 pF line-to-ground capacitance and fast clamping response. Its low capacitance prevents signal edge degradation, and its 350 W peak power rating handles transients common in both topologies. The SZNUP3105LT1G is explicitly referenced in onsemi's application diagrams for high-speed and fault-tolerant CAN protection, confirming functional suitability across these standards when correctly implemented with proper PCB layout and grounding.

What does the "SZ" prefix signify in SZNUP3105LT1G?

The "SZ" prefix in SZNUP3105LT1G indicates automotive-grade qualification: AEC-Q101 stress-tested, PPAP-capable, and manufactured under enhanced process controls for unique site and change management requirements. It distinguishes this variant from the standard NUP3105LT1G, which lacks automotive qualification. Both share identical electrical specs and package, but only the SZNUP3105LT1G is approved for production automotive applications - including engine control, chassis, and body electronics - where reliability and traceability are mandated.

Can the SZNUP3105LT1G be used in 12 V automotive systems?

Yes, the SZNUP3105LT1G is compatible with 12 V automotive systems despite being optimized for 24 V. Its 32 V reverse working voltage (V_RWM) provides sufficient margin above 12 V nominal rails, including load-dump transients up to ~40 V. All electrical parameters - including clamping voltage, leakage, and temperature range - remain valid. The SZNUP3105LT1G is commonly deployed in 12 V passenger car ECUs, especially where future platform scalability to 24 V or mixed-voltage architectures is planned. Its AEC-Q101 qualification applies equally across both voltage classes.