This part is a kind of semiconductor called BTB04.

Function of this product has SENSITIVE GATE TRIACS.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

BTA04 T/D/S/A BTB04 T/D/S/A SENSITIVE GATE TRIACS . . . FEATURES VERY LOW IGT = 10mA max LOW IH = 15mA max BTA Family : INSULATING VOLTAGE = 2500V(RMS) (UL RECOGNIZED : E81734) DESCRIPTION The BTA/BTB04 T/D/S/A triac family are high performance glass passivated PNPN devices. These parts are suitables for general purpose applications where gate high sensitivity is required. Application on 4Q such as phase control and static switching. ABSOLUTE RATINGS (limiting values) Symbol IT(RMS) RMS on-state current (360° conduction angle) Non repetitive surge peak on-state current ( Tj initial = 25°C ) I2t value Critical rate of rise of on-state current Gate supply : IG = 50mA diG/dt = 0.1A/µs Parameter BTA BTB A1 A2 G TO220AB (Plastic) Value Tc = 90°C Tc = 95°C tp = 8.3 ms tp = 10 ms tp = [ ... ]

BTB04 PDF Datasheet Download