This post explains for the NPN Transistor.
Part Number: D1554, 2SD1554
Function: 600V, 3.5A, NPN Transistor
Package: TO-3P type
Manufacturer: Toshiba
See the preview image and the PDF file for more information.
Image:
Description
This is 600V, 3.5A, NPN Triple Diffused Planar Silicon Transistor
Features
1. High Collector-Base Voltage : Vcbo = 1500V
2. Vceo = 600V, Vebo = 5V
3. High Speed Switching
Pinout:
Absolute maximum ratings ( Ta=25°C )
1. Collector to Base Voltage: Vcbo = 1500 V
2. Collector to Emitter Voltage: Vceo = 600 V
3. Emitter to Base Voltage: Vebo = 5 V
4. Collector Current: Ic = 3.5 A
5. Total Dissipation : Pc = 40 W
6. Junction Temperature: Tj = 150°C
7. Storage Temperature: Tsg = -55 ~ +150°C
D1554 Datasheet
