onsemi SM36T1G

Overview

SM36T1G from onsemi is a dual common-anode ESD protection diode array in SOT-23 package, designed for transient overvoltage and electrostatic discharge protection of two signal lines. It features 36 V working peak reverse voltage, 60 V clamping voltage at 1 A peak pulse current, 4.0 pF typical capacitance at 0 V, and 300 W peak pulse power (8/20 µs). It is used in USB, HDMI, and industrial I/O interfaces where board space and low capacitance are critical.

For engineers reviewing the SM36T1G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage under 1 A surge, sub-5 pF line-to-ground capacitance, dual-line common-anode topology, SOT-23 footprint compatibility, and AEC-Q101 qualification status for automotive-grade reliability.

Technical Context

The SM36T1G integrates two monolithic silicon avalanche diodes sharing a common anode (Pin 3), enabling bidirectional or dual unidirectional protection configurations. Its junction design provides fast response to ESD events per IEC 61000-4-2 (±26 kV contact) and lightning surges per IEC 61000-4-5 (12 A).

It operates with 1.0 µA maximum reverse leakage at 36 V VRWM and exhibits a breakdown voltage range of 40.0–46.95 V at 1 mA test current. Thermal resistance is 417 °C/W on alumina substrate and 556 °C/W on FR-5 board, supporting stable operation up to +150 °C junction temperature.

Key Specifications

Pinout & Package

SOT-23 package (2.90 × 1.30 × 1.00 mm, 1.90 mm pitch), void-free thermosetting plastic case with corrosion-resistant, solderable finish. Maximum solder temperature: 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 SM24T1G and TPD2E001DRYR, the SM36T1G offers the highest VRWM and lowest capacitance among SOT-23 dual-channel TVS diodes, making it optimal for 24–36 V industrial buses and high-speed data lines needing robust lightning-level surge immunity.

Availability

SM36T1G is available at Aetrix Electronics and suitable for industrial communication interfaces, automotive infotainment ports, and high-reliability USB/HDMI subsystems requiring stable component supply and long-term lifecycle support.

Supply support for SM36T1G 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 SM36T1G belongs to the SM05T1G Series of ESD protection diode arrays, engineered specifically for space-constrained, high-surge-immunity applications in computing, communications, and automotive electronics.

FAQ

What is the maximum clamping voltage of the SM36T1G under a 1 A 8/20 µs surge?

The SM36T1G has a maximum clamping voltage (V_C) of 60 V when subjected to a 1 A 8/20 µs transient pulse. This value is measured across the cathode-to-anode terminals and ensures downstream components-such as 3.3 V or 5 V interface ICs-are not exposed to damaging overvoltages during ESD or surge events. The clamping performance is guaranteed per the onsemi datasheet revision 11 (September 2024) and applies to both Pin 1–3 and Pin 2–3 configurations of the SM36T1G.

Is the SM36T1G suitable for protecting high-speed USB 2.0 data lines?

Yes, the SM36T1G is suitable for USB 2.0 data line protection due to its 4.0 pF typical capacitance at 0 V bias, which minimizes signal attenuation and jitter. Its dual-cathode configuration allows independent protection of D+ and D− while sharing a common anode ground connection. When placed within 2 mm of the USB connector and with proper ground plane design, the SM36T1G maintains signal integrity up to 480 Mbps without violating USB 2.0 eye diagram masks.

Does the SM36T1G meet automotive qualification standards?

The base SM36T1G is not AEC-Q101 qualified; however, its automotive-grade variant SZSM36T1G is fully AEC-Q101 qualified and PPAP capable. Both share identical electrical specifications and SOT-23 packaging, but the SZ-prefix version undergoes additional stress testing-including temperature cycling, HTRB, and ESD validation-to meet automotive reliability requirements. For automotive designs, specify SZSM36T1G to ensure compliance with ISO/TS 16949 and vehicle-level ESD immunity standards.

What is the thermal resistance of the SM36T1G on a standard FR-5 PCB?

The SM36T1G has a junction-to-ambient thermal resistance (R_JA) of 556 °C/W when mounted on a standard FR-5 board (1.0 × 0.75 × 0.62 in.). This value assumes no copper pour or thermal vias. With a 1 cm² 2-oz copper pad and four thermal vias, R_JA improves to approximately 200–250 °C/W. The device's 300 W peak pulse power rating is non-repetitive; sustained power dissipation must remain below 225 mW at 25°C ambient, derating linearly above that temperature.

Can the SM36T1G be used in a bidirectional protection configuration?

Yes, the SM36T1G supports bidirectional protection by connecting Pin 3 (anode) to ground and using Pins 1 and 2 as protected signal lines-each forming a unidirectional clamp to ground. While inherently dual unidirectional, the common-anode architecture allows effective bidirectional surge suppression when paired with appropriate grounding and layout. This configuration is validated in onsemi's application examples for keyboard terminal and microprocessor I/O protection, and is widely implemented in USB, HDMI, and RS-485 reference designs using the SM36T1G.