Operating and Storage Junction Temperature Range: -55 to +150 °C
Package: TO-3P
Pinout of 2SB1557-A
Here is an image showing the pin diagram of this transistor.
Classification of hFE
The 2SB1557-A transistor can have a current gain of 5000 to 12000. The gain of the 2SB1557 will be in the range from 5000 to 30000, for the 2SB1557-B it will be in the range from 9000 to 18000, for the 2SB1557-C it will be in the range from 15000 to 30000.
Equivalent circuit
Marking
Sometimes the "2S" prefix is not marked on the package - the 2SB1557-A might only be marked "B1557-A".
Replacement and Equivalent for 2SB1557-A transistor