Thyristors & TRIACs
Products (6)
BTA16-600B - 16A 600V Standard TRIAC | STMicroelectronics
The STMicroelectronics BTA16-600B is a 16 A standard TRIAC rated at 600 V repetitive peak off-state voltage, supplied in an insulated TO-220AB (BTA) package for general-purpose AC power switching. As part of the ST BTA/BTB16 glass-passivated PNPN family, it is engineered for applications where high surge current capability is required. A TRIAC (triode for alternating current) is a three-terminal bidirectional thyristor that conducts current in both directions once triggered by a gate pulse, making it the foundational switching device of the thyristor family for AC phase control. In the power-control hierarchy, the TRIAC sits alongside the SCR and AC switch, enabling direct switching of AC mains loads with a single semiconductor rather than back-to-back SCRs. Key features include a 16 A RMS on-state current rating, 600 V blocking capability suitable for 230 VAC and 120 VAC mains, and the fully insulated TO-220AB package, which allows mounting directly to a grounded heatsink without an external isolation pad, improving thermal performance and safety. The glass-passivated die construction provides robust surge immunity. The BTA16-600B is a standard (not snubberless) TRIAC with a gate sensitivity class denoted by the B suffix. Designers trigger it via negative or positive gate current relative to A1 using optocouplers or direct drive circuits. Four-quadrant triggering supports conventional phase-control topologies. Typical applications include static relays, heating regulation, AC motor control, light dimmers, and general ON/OFF mains switching in appliances and industrial equipment. A key design consideration: standard TRIACs require RC snubber networks when driving inductive loads such as motors, because the snubberless W variants (e.g., BTA16-600BW) trade commutation capability for noise immunity; verify gate sensitivity against your drive circuit. This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet, as of 2026-09-10.
BTA16-600BWRG - 600V 16A Snubberless TRIAC | STMicroelectronics
The STMicroelectronics BTA16-600BWRG is a Snubberless TRIAC (alternistor) rated for 600 V repetitive peak off-state voltage (VDRM) and 16 A RMS on-state current, housed in an insulated through-hole TO-220AB package. It is designed for general purpose mains power AC switching and ON/OFF control functions. A TRIAC is a three-terminal bidirectional thyristor that conducts current in either direction once triggered by a small gate current, making it the core switching element in AC power control. Within the power semiconductor hierarchy, the TRIAC sits alongside SCRs and AC switches as a member of the thyristor family, and the BTA16-600BWRG targets medium-current AC switching in the 16 A class. Key features include the Snubberless (3Q) commutation capability, which provides very high dI/dt commutation performance without requiring an external RC snubber network, and low thermal resistance achieved through clip bonding technology. The insulated BTA construction uses a low thermal resistance ceramic pad to electrically isolate the tab from the silicon, allowing direct mounting to a grounded heatsink. The BTA series is UL1557 certified. Architecturally, the Snubberless BWRG grade is engineered for applications with demanding commutation conditions, such as inductive loads and motor control, where standard 4Q TRIACs would require snubber networks to prevent false re-triggering. Clip bonding reduces thermal resistance between the die and the package, improving current handling and junction temperature margins compared to wire-bonded alternatives. Typical applications include AC motor speed control, resistive and inductive heater regulation, solid-state relays, light dimmers for inductive loads, and home appliance power switching on 110/230 VAC mains. The 600 V rating provides ample margin for 230 VAC lines with transient excursions. Design-wise, choose an adequate heatsink based on on-state power dissipation (approximately 1.55 V x IT average), and respect the 50 mA gate trigger current requirement when sizing the gate drive. Estimate junction temperature using the TO-220 thermal resistance with the ceramic isolation accounted for. This page synthesizes distributor pricing, drop-in alternatives within the BTA16 family, and practical design notes not consolidated in the manufacturer datasheet.
CMPP6027R - 40V 150mA Programmable UJT SOT-23 | Central Semiconductor
The Central Semiconductor CMPP6027R is a surface mount silicon programmable unijunction transistor (PUT) rated for 40V anode-to-cathode voltage and 150mA peak output current, housed in a SOT-23 (TO-236-3 / SC-59 / SOT-23-3) package with 167 mW power dissipation. Its trip parameters - peak current (IP), valley current (IV), and intrinsic standoff ratio (eta) - are programmable through an external resistor divider on the gate. A programmable unijunction transistor (PUT) is a four-layer PNPN threshold switching device whose anode-gate-cathode terminals resemble a small thyristor. Unlike a fixed-ratio UJT, a PUT fires when the anode voltage exceeds the gate voltage plus one PN junction drop, and because the gate is externally accessible, designers set the trigger threshold, peak current, valley current, and standoff ratio with two resistors. PUTs therefore occupy the same functional niche as neon lamps and Schmitt triggers in low-frequency relaxation oscillators, timing circuits, and voltage-detection latches within the broader thyristor and semiconductor family. Key differentiating features of the CMPP6027R include its 40V anode-cathode rating for headroom on industrial rails, 150mA pulse output capability sufficient to drive optocoupler LEDs or thyristor gates directly, fully adjustable IP and IV characteristics, and the compact SOT-23 surface mount footprint that lets designers retrofit through-hole PUT designs such as the 2N6027 into modern PCBs. The device complements Central Semiconductor's CMPP6028R, which offers a different intrinsic standoff ratio binning within the same package. Architecturally, the CMPP6027R is an anode-gate thyristor: forward biasing the anode-gate junction injects gate current, regeneratively turns on the PNPN structure, and latches the anode-cathode path into conduction until the anode current falls below the programmable valley current. This negative-resistance switching behavior is the basis of its use in relaxation oscillators and level-sensitive triggers. Typical applications include sawtooth and pulse relaxation oscillators, time-delay timers, thyristor and triac gate triggering, overvoltage crowbar sensing, and voltage-monitoring alarm circuits where a precise, adjustable threshold is required at minimal BOM cost. Design consideration: because IP, IV, and eta are set by the external R1-R2 gate divider, resistor tolerance directly shifts the trip point; use 1% resistors and confirm the divider current comfortably exceeds the datasheet peak current at the lowest operating temperature. This page adds value beyond the datasheet by consolidating distributor availability, drop-in alternative analysis, application guidance, and pricing context for the CMPP6027R in one reference.
CMPP6028R - 40V, 150mA Programmable UJT, SOT-23 | Central Semiconductor
The Central Semiconductor CMPP6028R is a silicon programmable unijunction transistor (PUT) rated at 40 V and 150 mA, housed in a surface-mount SOT-23 package. Unlike a conventional unijunction transistor, a PUT allows designers to program key characteristics - valley current (IV), peak current (IP), and the intrinsic standoff ratio (eta) - through two external resistors. A programmable unijunction transistor is a four-layer PNPN device belonging to the thyristor family. It behaves as a voltage-triggered switch: when the anode voltage exceeds a threshold set by the gate divider network, the device fires and conducts from anode to cathode. PUTs are widely used as relaxation oscillators, timing circuits, voltage detectors, and SCR trigger devices, occupying the low-power end of the power-management and discrete-semiconductor hierarchy. Key features of the CMPP6028R include a 40 V anode-to-cathode voltage rating, a 150 mA maximum current capability, and a compact SOT-23 surface-mount package suitable for automated assembly. The programmability of IP, IV, and eta gives it flexibility that fixed-parameter UJTs cannot offer, allowing one part number to serve many oscillator and timing designs. Architecturally, the CMPP6028R implements the anode-gate-cathode structure of a PUT with the gate accessible on a package pin. The intrinsic standoff ratio and peak/valley currents are set externally: increasing the gate divider resistance raises the standoff ratio and reduces peak current, tuning oscillator frequency and triggering thresholds. Maximum power dissipation for this family is 167 mW per the manufacturer data. Typical applications include relaxation oscillators, long-duration timers, overvoltage detectors, lamp flashers, and gate-trigger circuits for SCRs and triacs in low-power industrial and consumer designs. Design consideration: keep total dissipation within the 167 mW package limit and ensure the external divider current substantially exceeds the valley current so oscillation does not stall. This page synthesizes distributor availability data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
CS223-4M - 4A 600V Surface Mount SCR | Central Semiconductor
The Central Semiconductor CS223-4M is a 4 A surface mount silicon controlled rectifier (SCR) rated at 600 V blocking voltage, housed in the SOT-223 (TO-261AA) epoxy molded package. According to the manufacturer datasheet, the CS223 family covers 600 V through 800 V grades in a 4.0 A rating, and the CS223-4M is specifically the 600 V member of that family. An SCR, or silicon controlled rectifier, is a three-terminal thyristor that acts as a latching switch: once a small gate trigger current is applied between gate and cathode, the device conducts from anode to cathode and remains on until the anode current falls below the holding current. In the power-electronics hierarchy, the SCR sits among thyristors alongside TRIACs and DIACs, and is the workhorse of half-wave and full-wave controlled rectification, crowbar overvoltage protection, and phase-control circuits. Key features of the CS223-4M include a 4.0 A average on-state current rating, 600 V repetitive peak off-state voltage, a compact surface mount SOT-223 case with a thermally conductive tab, and epoxy molded construction designed for sensing circuit applications and control systems. The SOT-223 tab (which is electrically common to the anode) provides a low-resistance thermal path to the PCB copper, allowing several watts of dissipation without an external heatsink. The device uses standard-recovery silicon thyristor technology optimized for line-frequency (50/60 Hz) applications rather than high-frequency switching. Its latching behavior makes it well suited to crowbar circuits that dump fault energy into a shunt path, overvoltage sensing, and gating of loads driven from rectified AC mains. Typical applications include AC power control, overvoltage crowbar protection in linear power supplies, sensing and alarm latch circuits, and industrial control systems where a robust, low-cost latching switch is required. When designing with this SCR, ensure the gate trigger current is available under worst-case cold-temperature conditions, and verify that latching current is reached before the trigger pulse ends; a snubber across anode-cathode suppresses dv/dt false triggering. This page synthesizes distributor data, drop-in family alternatives, and practical design notes not found in the manufacturer datasheet.
CS223-4M-TR-PBFREE - 600V 4A SOT-223 SCR | Central Semiconductor
The Central Semiconductor CS223-4M-TR-PBFREE is a 600V, 4A (RMS) surface mount silicon controlled rectifier (SCR) rated for 30A surge current, housed in a 4-pin (3+tab) SOT-223 epoxy-molded package supplied on tape and reel. It is a lead-free, Pb-free device designed for sensing circuit applications and control systems. An SCR (silicon controlled rectifier), also called a thyristor, is a four-layer semiconductor device that acts as a latching switch: once triggered by a small gate current, it conducts from anode to cathode until the current falls below the holding level. Within the power-semiconductor hierarchy, the thyristor family sits alongside MOSFETs and IGBTs as a power switching device, and SCRs remain the preferred solution for AC line-controlled latching functions due to their ruggedness and low conduction loss. Key features of the CS223-4M include a 600V off-state voltage rating, a maximum gate trigger voltage (Vgt) of 800 mV, and a very sensitive maximum gate trigger current (Igt) of 200 uA. This high gate sensitivity allows direct driving from low-power sensing circuits, microcontroller ports, or optocoupler outputs without an external gate driver stage, reducing bill-of-material cost and board area. The epoxy-molded SOT-223 construction provides good thermal performance for a compact surface-mount footprint; the tab (pin 4) is electrically part of the anode path and solders to the PCB copper area for heat spreading. The device is a standard-recovery SCR, suited to 50/60 Hz line-frequency phase control and crowbar circuits rather than high-frequency switching. Typical applications include overvoltage crowbar protection in power supplies, AC line latching control, sensing and alarm trip circuits, and industrial control systems where a small signal must latch a larger load current. Design consideration: because the gate is highly sensitive (200 uA max Igt), keep the gate trace short and add a gate-to-cathode resistor (typically 1k ohm) to prevent false triggering from leakage or noise pickup. This page synthesizes distributor availability data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.