The BD 875, BD 877 and BD 879 are epitaxial NPN silicon planar Darlington transistors supplied in a TO‑126 plastic package. They are intended for relay drivers and general audio‑frequency applications and are offered as complementary pairs with the PNP series BD 876/878/880.
The document lists maximum voltage and current ratings, power dissipation limits, temperature ranges, and dynamic parameters such as transition frequency. It also provides ordering codes, mechanical dimensions, and recommended mounting torque for the M3 fixing screw.
| Collector‑emitter voltage (VCEO) | 45 V (BD 875), 60 V (BD 877), 80 V (BD 879) |
|---|---|
| Total power dissipation (Prot) | 1.25 W (BD 875/877), 4.28 W (BD 879) |
| Junction temperature (Tj) | 160 °C (BD 875/877), 150 °C (BD 879) |
| Storage temperature range (Tstg) | -65 °C to +150 °C |
| Transition frequency (fT) | 200 MHz (all three models) |
| Mounting torque | Maximum 0.8 Nm |
The BD 877 can withstand up to 60 V collector‑emitter voltage.
The transistors should be mounted with a starting torque not exceeding 0.8 Nm.
The devices can be stored from –65 °C up to +150 °C.
All three models have a transition frequency of about 200 MHz.