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STMicroelectronics TS420-400B-TR
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- Part No.:
- TS420-400B-TR
- Manufacturer:
- STMicroelectronics
- Category:
- SCRs
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
TS420-400B-TR.pdf
- Description:
- SCR 400V 4A DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:9,020
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Product details
Overview
TS420-400B-TR from STMicroelectronics is a sensitive-gate 4 A, 600 V RMS SCR designed for low-gate-current triggering in constrained drive circuits. It delivers 4 A RMS on-state current, 600 V repetitive peak off-state voltage (VDRM/VRRM), and ultra-low 200 µA max gate trigger current (IGT) at 25 °C - enabling direct microcontroller GPIO or optocoupler-driven control in motor control and crowbar protection.
For engineers reviewing the TS420-400B-TR datasheet, TS420-400B-TR pinout, TS420-400B-TR application, or TS420-400B-TR equivalent, key selection criteria include gate sensitivity (≤200 µA IGT), dV/dt immunity (≥5 V/µs at 125 °C), holding current (≤5 mA IH), thermal resistance (3.0 °C/W j-c), and DPAK surface-mount compatibility for high-density PCB layouts.
Technical Context
This SCR operates as a latching unidirectional power switch triggered by a brief gate pulse. Its sensitive gate enables reliable turn-on with sub-milliampere gate drive, eliminating external amplification in battery-powered or low-power control stages. The device sustains 600 V blocking in both forward and reverse directions and maintains stable turn-off behavior up to 125 °C junction temperature.
Turn-on is governed by gate-controlled dynamics (tGT = 0.5 µs typ.), while commutation relies on natural current zero-crossing or forced circuit interruption. Critical design parameters include minimum dV/dt immunity (5 V/µs), maximum I²t rating (4.5 A²s), and dynamic on-state resistance (90 mΩ max), all validated across -40 to +125 °C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| IT(RMS) | 4 A - Sustains continuous 4 A RMS load current at TC = 115 °C without derating beyond thermal limits. |
| VDRM / VRRM | 600 V - Blocks up to 600 V peak in both forward and reverse directions under repetitive conditions. |
| IGT (max) | 200 µA - Triggers reliably with ≤200 µA gate current at 12 V, compatible with logic-level drivers. |
| dV/dt (min) | 5 V/µs - Immune to false turn-on from rapid voltage transients when RGK = 220 Ω at 125 °C. |
| Rth(j-c) | 3.0 °C/W - Enables efficient heat transfer from junction to case, supporting high-power density mounting. |
| VTM (max) | 1.6 V - On-state voltage drop ≤1.6 V at 8 A pulse, minimizing conduction loss and self-heating. |
| IH (max) | 5 mA - Holds conduction state until load current falls below 5 mA, ensuring stable latching. |
Pinout & Package
TS420-400B-TR uses the DPAK (TO-252) surface-mount package with three terminals: Anode (A), Cathode (K), and Gate (G). Thermal pad is electrically connected to the cathode and must be soldered to a copper pour for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Main current entry terminal | Carries full load current into the device; connects to positive side of AC line or DC bus. |
| Cathode (K) | Main current exit terminal & thermal reference | Carries full load current out; electrically tied to exposed thermal pad for heatsinking. |
| Gate (G) | Control input for turn-on initiation | Accepts low-energy pulse (≤200 µA) to initiate conduction; requires no sustained drive current. |
Key Features
| Feature | Design Value |
|---|---|
| Sensitive gate triggering | Max 200 µA IGT enables direct MCU or optocoupler drive without buffer transistors. |
| High dV/dt immunity | 5 V/µs minimum ensures robust operation in noisy AC line environments with fast transients. |
| Low on-state voltage | 1.6 V max VTM reduces power dissipation and thermal stress during conduction. |
| Thermal efficiency | 3.0 °C/W junction-to-case resistance supports compact designs with minimal heatsinking. |
| Lead-free & RoHS-compliant | ECOPACK®-qualified DPAK meets UL 94 V0 flammability and environmental compliance standards. |
Applications
| Power Tool Motor Control | Kitchen Appliance Speed Regulation |
|---|---|
Use Scenario: Variable-speed universal motor control in cordless drills and sanders using phase-angle AC triggering. IC Role / Device Role / Timing Role: Main power switching element triggered by zero-crossing synchronized gate pulses to regulate average motor torque. Use Value: Ultra-low IGT allows direct drive from low-power microcontrollers, reducing BOM count and PCB area. | Use Scenario: Fan speed and heating element duty control in blenders, coffee makers, and food processors. IC Role / Device Role / Timing Role: AC line-switching SCR providing precise half-cycle conduction control via microcontroller-timed gate pulses. Use Value: 600 V VDRM supports global 230 VAC mains operation; 4 A IT(RMS) handles typical appliance loads up to 900 W. |
| Low-Power Supply Crowbar Protection | Industrial Sensor Interface Protection |
Use Scenario: Overvoltage shutdown circuit clamping output of 12–24 V DC supplies during regulator failure. IC Role / Device Role / Timing Role: Fast-acting crowbar device shorting supply output to ground upon overvoltage detection signal. Use Value: 0.5 µs tGT ensures sub-microsecond response; 30 A non-repetitive surge rating absorbs transient energy safely. | Use Scenario: Transient suppression on analog sensor inputs exposed to ESD or inductive coupling in factory automation. IC Role / Device Role / Timing Role: Bidirectional voltage clamp activated by overvoltage exceeding VDRM/VRRM threshold. Use Value: Symmetrical 600 V blocking capability protects both polarities; 1 mA IRRM ensures minimal leakage during normal operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar SCR applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BT169G-TR | Lower IT(RMS) = 0.8 A; higher IGT = 500 µA; TO-92 package | Not suitable for >1 A loads; limited thermal capacity; through-hole only | Select only for low-power signal-level switching where gate drive margin exceeds 500 µA. |
| TYN612 | Higher IT(RMS) = 12 A; same VDRM = 600 V; TO-220AB package; IGT = 15 mA | Requires gate driver amplification; larger footprint; better for industrial motor starters | Choose when higher surge current (100 A) and thermal mass are required, accepting higher gate drive burden. |
Compared with BT169G-TR and TYN612, TS420-400B-TR uniquely balances ultra-sensitive triggering (200 µA), 4 A RMS rating, and DPAK surface-mount compatibility - making it optimal for space-constrained, microcontroller-driven AC control where gate drive power and PCB real estate are critical.
Availability
TS420-400B-TR is available at Aetrix Electronics and suitable for motor control in power tools, crowbar protection in low-power supplies, and AC load switching in kitchen appliances requiring stable component supply and long-term manufacturing continuity.
Supply support for TS420-400B-TR 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-sensitivity SCR product line, engineered specifically for applications where gate drive current is severely limited - such as battery-operated tools, energy-efficient appliances, and compact power protection circuits.
FAQ
What is the maximum gate trigger current (IGT) specification for TS420-400B-TR?
The maximum gate trigger current is 200 µA at VD = 12 V and RL = 33 Ω, measured at 25 °C. This value increases slightly with junction temperature but remains ≤500 µA up to 125 °C per Figure 5 in the datasheet. It defines the worst-case gate drive requirement for guaranteed turn-on.
Can TS420-400B-TR be used in DC circuits?
Yes, but only in forced-commutated configurations where load current can be actively interrupted (e.g., via MOSFET or relay). As a standard SCR, it cannot self-commutate in pure DC - conduction continues until anode current falls below the 5 mA holding current (IH) or is externally forced to zero.
Is the DPAK thermal pad electrically isolated?
No - the exposed thermal pad on the TS420-400B-TR DPAK package is internally connected to the cathode (K) terminal. PCB layout must ensure this pad is routed to the cathode net and not shorted to other potentials, while maintaining adequate copper area for thermal dissipation.
Does TS420-400B-TR support bidirectional AC switching?
No - it is a unidirectional SCR and conducts only from anode to cathode. For full-wave AC control, two SCRs must be connected in inverse-parallel, or a TRIAC (e.g., BTA16-600BRG) should be selected instead. Its VRRM = 600 V provides reverse blocking, not reverse conduction.
TS420-400B-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Voltage - Off State:
- 400 V
- Voltage - Gate Trigger (Vgt) (Max):
- 800 mV
- Current - Gate Trigger (Igt) (Max):
- 200 µA
- Voltage - On State (Vtm) (Max):
- 1.6 V
- Current - On State (It (AV)) (Max):
- 2.5 A
- Current - On State (It (RMS)) (Max):
- 4 A
- Current - Hold (Ih) (Max):
- 5 mA
- Current - Off State (Max):
- 5 µA
- Current - Non Rep. Surge 50, 60Hz (Itsm):
- 30A, 33A
- SCR Type:
- Sensitive Gate
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
TS420-400B-TR FAQ
1.How can I place an order for TS420-400B-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for TS420-400B-TR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TS420-400B-TR reliable?
The price and inventory of TS420-400B-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS420-400B-TR is usually 5 days.
3.What payment methods are accepted for TS420-400B-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS420-400B-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS420-400B-TR?
TS420-400B-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS420-400B-TR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TS420-400B-TR?
For technical support, including TS420-400B-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS420-400B-TR requirements.
6.How does Aetrix verify that TS420-400B-TR is sourced from the original manufacturer or authorized distributors?
All TS420-400B-TR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TS420-400B-TR meets industry standards.
7.What is the process for return or replacement of TS420-400B-TR?
All TS420-400B-TR units undergo pre-shipment inspection (PSI). If there is an issue with TS420-400B-TR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TS420-400B-TR part is unused and in its original packaging.
Return procedure for TS420-400B-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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