This part is a kind of semiconductor called BD438.

Function of this product has COMPLEMENTARY SILICON POWER TRANSISTORS.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

BD433/5/7 ® BD434/6/8 COMPLEMENTARY SILICON POWER TRANSISTORS s STMicroelectronics PREFERRED SALESTYPE s COMPLEMENTARY PNP - NPN DEVICES DESCRIPTION The BD433, BD435, and BD437 are silicon epitaxial-base NPN power transistors in Jedec SOT-32 plastic package, intented for use in medium power linear and switching applications. The BD433 is especially suitable for use in car-radio output stages. The complementary PNP types are BD434, BD436, and BD438 respectively. 1 2 3 SOT-32 INTERNAL SCHEMATIC DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol Parameter VCBO Collector-Base Voltage (IE = 0) VCES Collector-Emitter Voltage (VBE = 0) VCEO Collector-Emitter Voltage (IB = 0) VEBO Emitter-Base Voltage (IC = 0) IC Collector Current ICM Collector Peak Current (t ≤ 10 ms) IB Base Current Ptot Total D [ ... ]

BD438 PDF Datasheet Download