Dual NPN pre-biased transistor in a compact SOT-563 package
The ROHM Semiconductor EMH9T2R integrates two NPN pre-biased transistors in a single SOT-563 / SOT-666 package, each with a 10 kΩ base resistor (R1) and a 47 kΩ base-emitter resistor (R2). This bias network eliminates the need for external resistors, saving board space and reducing component count in switching and interface circuits. Each transistor is rated for a collector-emitter breakdown voltage of 50 V and a maximum collector current of 100 mA, with a transition frequency of 250 MHz. The 150 mW power dissipation limit per package sets the thermal budget for both channels combined.
Sizing the load: 50 V and 100 mA limits
The 50 V VCEO breakdown and 100 mA continuous collector current define the switching envelope. For a 24 V relay or solenoid driver, the voltage margin is comfortable; the 100 mA limit means each channel can drive a small relay coil or an optocoupler LED directly. The 300 mV saturation voltage at 250 µA base drive and 5 mA collector current gives a low on-state drop for logic-level loads.
Package and footprint for dense layouts
The SOT-563 / SOT-666 package (EMT6 supplier device package) is an ultra-small, 6-lead surface-mount package. The 0.5 mm lead pitch and compact body suit space-constrained designs such as portable electronics, sensor modules, and multi-channel I/O blocks.