Dual PNP pre-biased transistor in SOT-553
The RN2709JE(TE85L,F) from Toshiba Semiconductor integrates two PNP transistors with built-in bias resistors in a single SOT-553 package — a space-saving option for switching and interface circuits where external resistor networks would otherwise consume board area. Each transistor is rated for 50 V collector-emitter breakdown and 100 mA continuous collector current, with a maximum power dissipation of 100 mW for the dual device.
Built-in bias resistors set the switching threshold
The base resistor (R1) is 47 kΩ and the base-emitter resistor (R2) is 22 kΩ — this divider network sets the turn-on threshold and provides a leakage path to ground, keeping the transistor off when the drive signal is absent. The 200 MHz transition frequency means the transistor can handle switching applications well into the low-MHz range, though the bias resistor network will limit the practical switching speed more than the fT itself.