STMicroelectronics TS420-600B

Overview

TS420-600B from STMicroelectronics is a sensitive-gate silicon-controlled rectifier (SCR) rated for 4 A RMS on-state current and 600 V repetitive peak off-state voltage (V_DRM/V_RRM), with ultra-low 200 µA maximum gate trigger current (I_GT). It operates as a latching power switch in AC line-controlled circuits, enabling reliable turn-on with minimal drive-ideal for motor control in cordless hand tools and overvoltage crowbar protection in low-power SMPS.

For engineers reviewing the TS420-600B datasheet, TS420-600B pinout, TS420-600B application, or TS420-600B equivalent, key selection criteria include its 0.2 mA sensitivity threshold, 1.6 V max on-state voltage at 8 A, 5 V/µs minimum dV/dt immunity at 125 °C, thermal resistance of 3.0 °C/W (junction-to-case), and DPAK surface-mount package compatibility with standard PCB layout practices.

Technical Context

The TS420-600B employs a planar passivated junction structure optimized for high dV/dt immunity (≥5 V/µs at T_j = 125 °C) and stable triggering across temperature. Its gate sensitivity is achieved via tailored doping profiles that reduce I_GT to ≤200 µA while maintaining robust holding current (I_H ≤ 5 mA) and latching current (I_L ≤ 6 mA).

It supports phase-angle control and zero-crossing switching topologies, with gate-controlled turn-on time (t_GT) of 0.5 µs (typ.) and circuit-controlled turn-off time (t_Q) of 60 µs (typ.) under defined load and commutation conditions-enabling precise timing in compact AC power management designs.

Key Specifications

Pinout & Package

DPAK (TO-252) package: single-sided heat dissipation design with exposed drain tab (cathode-connected metal pad) for thermal enhancement; 3-terminal configuration compatible with automated SMT assembly and reflow profiles per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SCR-based AC switching applications.

Compared with BT169G-TR and TYN612, the TS420-600B uniquely balances 600 V rating, 200 µA sensitivity, and DPAK packaging-making it the only option among the three viable for 230 VAC SMT motor control without gate buffering or heatsinking.

Availability

TS420-600B is available at Aetrix Electronics and suitable for motor control in cordless power tools, overvoltage crowbar protection in low-power SMPS, and AC fan speed regulation requiring stable component supply, RoHS-compliant packaging, and consistent DPAK thermal performance.

Supply support for TS420-600B 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The TS420 belongs to ST's high-reliability SCR product line targeting compact, energy-efficient AC power control-designed specifically for SMT integration in space-constrained, thermally demanding applications like portable power tools and DIN-rail-mounted power supplies.

FAQ

What is the maximum junction temperature for continuous operation?

The TS420-600B has a maximum operating junction temperature of +125 °C, validated under DC or 180° conduction angle conditions. Derating is required above case temperatures of 115 °C, where RMS current must be reduced per Figure 2 in the datasheet to maintain reliability and prevent thermal runaway.

Can TS420-600B be used in zero-crossing switch applications?

Yes-it supports zero-crossing operation when paired with a zero-crossing detector and appropriate gate timing circuitry. Its 0.5 µs typical gate turn-on time and low I_GT allow precise synchronization; however, it does not integrate zero-crossing detection and requires external control logic to generate the gate pulse at the desired phase angle.

Is the DPAK package lead-free and RoHS compliant?

Yes-the TS420-600B is supplied in an ECOPACK®-compliant DPAK package with lead-free terminations and halogen-free epoxy meeting UL 94 V0 flammability rating. The "B" suffix in the order code explicitly denotes the RoHS-compliant version per ST's ECOPACK® grading system.

How does the gate-cathode resistance affect dV/dt immunity?

Increasing gate-cathode resistance (R_GK) improves dV/dt immunity-Figure 7 shows dV/dt increases by ~2× when R_GK rises from 100 Ω to 1 kΩ. However, excessive R_GK (>2.2 kΩ) risks unreliable turn-on due to increased sensitivity to noise; ST recommends 220 Ω for balanced performance per Table 4 test conditions.