TO252-3 Transistor Adapter Board
author: Eric
2 layer board of 0.34 x 0.69 inches (8.6 x 17.6 mm)
Uploaded:
April 19, 2025
Shared:
April 19, 2025
Total Price:
$1.15
Board to adapt TO252-3 transistors to 0.1" pitch through-hole. I used them to replace transistors in a circa-1990 NAD 5000 CD player (Q101-Q109). The original transistors (Qodd: 2SB1237 PNP / Qeven: 2SD1858 NPN) are obsolete Rohm Semiconductor parts and I couldn’t find good replacements in a through-hole package. Instead, I replaced then with onsemi 2SB1215 PNP and 2SD1815 NPN which are parametrically similar, handle more power and are still active and available.
The centers of the three through-holes in this board are spaced 0.158" from the bottom edge of the board for this Sullins right-angle header (holes are purposely tight; wiggle the connector pins and they’ll go through). The large TO252-3 pad (collector) is surrounded by thermal vias and both sides of the board are copper floods connected to the collector. Suggest ordering 2oz copper to maximize heat transfer to the board.
Board to adapt TO252-3 transistors to 0.1" pitch through-hole. I used them to replace transistors in a circa-1990 NAD 5000 CD player (Q101-Q109). The original transistors (Qodd: 2SB1237 PNP / Qeven: 2SD1858 NPN) are obsolete Rohm Semiconductor parts and I couldn’t find good replacements in a through-hole package. Instead, I replaced then with onsemi 2SB1215 PNP and 2SD1815 NPN which are parametrically similar, handle more power and are still active and available.
The centers of the three through-holes in this board are spaced 0.158" from the bottom edge of the board for this Sullins right-angle header (holes are purposely tight; wiggle the connector pins and they’ll go through). The large TO252-3 pad (collector) is surrounded by thermal vias and both sides of the board are copper floods connected to the collector. Suggest ordering 2oz copper to maximize heat transfer to the board.
