45 V, 500 mA NPN — general-purpose switching and amplification
With a DC current gain (hFE) of 100 minimum at 100 mA collector current and 1 V Vce, it suits general-purpose switching, driver stages, and linear amplifier circuits in low-to-medium power applications. The 170 MHz transition frequency supports moderate-speed switching up to a few tens of megahertz.
Last-time-buy — plan the BOM transition
Buyers should secure final lifetime quantities or qualify a replacement before the last order window closes. The base product number is BC817; the suffix denotes the hFE grouping and the package variant.
Package and thermal — PG-SOT23 layout notes
The PG-SOT23 package (TO-236-3 / SC-59 / SOT-23-3) is a standard three-lead surface-mount footprint. Maximum power dissipation is 500 mW; at 150°C junction temperature, derating is necessary above 25°C ambient. For continuous operation near 500 mA, ensure adequate copper area on the collector pad to spread heat. The 100 nA maximum collector cutoff current (ICBO) confirms low leakage at room temperature, but expect an order-of-magnitude increase at 150°C junction.