Pre-biased dual transistor — 22k/47k resistor network
The Toshiba RN4988,LXHF(CT integrates one NPN and one PNP pre-biased transistor in a single SOT-363 package, each with a 22 kΩ base resistor (R1) and 47 kΩ emitter-base resistor (R2). Rated for 50 V collector-emitter breakdown and 100 mA maximum collector current, with a 200 mW power dissipation ceiling — sized for low-current switching and interface duties in automotive and industrial control boards. The built-in bias network eliminates two external resistors per transistor channel, shrinking the BOM footprint and reducing placement cost on high-density SMT assemblies.
Switching performance and saturation
Minimum DC current gain of 80 at 10 mA, 5 V ensures consistent drive strength across the operating range; the NPN side transitions at 250 MHz, the PNP at 200 MHz. Vce saturation is 300 mV maximum at 250 µA base current and 5 mA collector current — low enough to keep conduction losses negligible in logic-level load switching. Collector cutoff current is 500 nA maximum; the pre-biased resistors hold the base at a defined potential, so the transistor stays off cleanly in high-impedance nodes.