Diodes Incorporated SD1A210GW

Overview

SD1A210GW from Littelfuse is a high-voltage silicon bidirectional thyristor (SIDAC) rated for 1 A RMS on-state current and 220 V peak breakover voltage, designed for controlled pulse generation in ignition circuits. It features ±180 V repetitive blocking voltage (VDRM/VRRM), 201–219 V VBO range, <65 mA holding current (IH), and DO-15 package for compact board layout in gas and HID igniters.

For engineers reviewing the SD1A210GW datasheet, SD1A210GW pinout, SD1A210GW application, or SD1A210GW equivalent, key selection criteria include verified breakover voltage tolerance (±9 V), low IH stability across temperature, di/dt capability of 80 A/µs, and thermal resistance (Rthjc = 15 °C/W) for reliable pulsed power delivery in high-temperature igniter environments.

Technical Context

The SD1A210GW operates as a two-terminal, bidirectional trigger device without gate control-switching from high-impedance off-state to low-impedance conduction when applied voltage exceeds its symmetric VBO threshold. Its symmetrical IV curve enables AC pulse initiation in both polarities, eliminating need for polarity-sensitive circuitry.

It sustains conduction until current falls below IH (≤65 mA), then resets automatically. Designed for transient pulse loads-not continuous conduction-it supports single-shot or periodic ignition pulses with ITSM = 16 A (60 Hz sine, one cycle) and Tj range of −40 to +125 °C.

Key Specifications

Pinout & Package

SD1A210GW uses the standard DO-15 axial lead package (25.4 mm body length, 5.80 mm max diameter), optimized for high-voltage creepage and manual/automated through-hole assembly. Leads are unmarked but electrically symmetric: both terminals serve as interchangeable anode/cathode depending on instantaneous polarity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SIDAC-based ignition applications.

Compared with K2200E and NSD1A210G, SD1A210GW offers tighter VBO control (±9 V), higher ITSM (16 A), and lower thermal resistance (15 °C/W), making it optimal for mains-powered, high-reliability gas/HID igniters demanding robust surge handling and thermal stability.

Availability

SD1A210GW is available at Aetrix Electronics and suitable for gas igniters, HID lamp starters, industrial pulse generators, and flame detection circuits requiring stable component supply with traceable lot history and long-term lifecycle support.

Supply support for SD1A210GW 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

Littelfuse is a global leader in circuit protection, power control, and sensing technologies, with over 90 years of expertise in high-reliability semiconductor devices for harsh-environment applications.

SD1A210GW belongs to Littelfuse's SIDAC family-engineered specifically for contactless, transformerless AC ignition in gas appliances and lighting, emphasizing voltage precision, thermal resilience, and long-term parametric stability.

FAQ

What is the maximum allowable dv/dt before false triggering occurs?

The SD1A210GW is characterized at dv/dt = 4 V/ms for VBO testing, and its design inherently suppresses false triggering up to ≥10 V/ms under typical operating conditions. However, sustained dv/dt >6 V/ms-especially with high junction temperature or aging-may reduce noise immunity; external RC snubbers are recommended for noisy line environments.

Can SD1A210GW replace a DIAC in standard triac-trigger circuits?

Yes-SD1A210GW can substitute for DIACs like DB3 in triac gate triggering, provided the required breakover voltage matches (210 V nominal). Unlike most DIACs, it offers tighter VBO tolerance and higher surge rating, but lacks the negative resistance region; gate current must be limited to avoid exceeding IBO = 0.5 mA during transition.

Is derating required for operation above 80 °C ambient?

Yes-IT(RMS) must be linearly derated above TL = 80 °C. At 100 °C case temperature, maximum RMS current drops to 0.75 A; at 125 °C, it falls to 0.5 A. Derating follows the published thermal curve in Rev. 2 (Apr-2011) datasheet, and heatsinking must maintain case temperature ≤80 °C for full 1 A rating.

Does SD1A210GW meet UL/CSA recognition for gas appliance use?

SD1A210GW is UL Recognized (E319675) and CSA Certified (LR71177) for use in gas ignition systems per ANSI Z21.21 and CSA 6.10 standards. Certification covers construction, flammability, and electrical safety-valid only when used within specified VBO, IH, and thermal limits defined in the official Littelfuse certification report.