2N3906 Pinout
2N3906 PNP Transistor · General-purpose PNP transistor; the PNP complement of the 2N3904, for small-signal switching / amplification.
TO-92 flat (printed) face toward you, pins down: left to right is E-B-C (Emitter, Base, Collector) — the same pin order as the 2N3904, but it is a PNP. Note this differs from the European BC557 (C-B-E).
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | E · Emitter | I/O | Emitter |
| 2 | B · Base | Input | Base (control) |
| 3 | C · Collector | Output | Collector |
How to read the 2N3906 pinout
- 01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
- 02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
- 03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.
Frequently asked questions
What is the 2N3906 pin order?
In the TO-92 package, flat face toward you and pins down, left to right is E-B-C (Emitter, Base, Collector) — the same as the 2N3904 NPN. Watch out: the BC557 PNP uses the opposite C-B-E order.
What is the 2N3906 used for?
It is the standard PNP partner to the 2N3904 NPN: small-signal switching and amplification up to about 200 mA. Put the emitter to the positive rail and pull the base low through a resistor to turn it on.
Pinout data comes from onsemi 2N3906 datasheet (standard TO-92 numbering). Refer to the actual device datasheet as authoritative for the pinout.