PNP switching transistor in a compact SC-70 footprint
The Infineon BC 807-40W H6433 is a PNP epitaxial planar transistor designed for general-purpose switching and amplification in surface-mount assemblies. Key ratings include a 45 V collector-emitter breakdown voltage and a 500 mA continuous collector current, giving it headroom for driving relays, small solenoids, or LED arrays in low-to-moderate power rails.
Gain and switching performance at operating current
The DC current gain (hFE) is specified at a minimum of 250 when the collector current is 100 mA and Vce is 1 V. That is the point most designers will check for saturation margin in a switching application — a gain floor of 250 means the base drive can be relatively light, which simplifies the drive circuit. The transition frequency of 200 MHz indicates it can handle moderate-speed switching, well above audio or low-frequency PWM, though the SC-70 package's thermal limits will constrain continuous dissipation before the silicon's speed does.
Saturation voltage and leakage at temperature
Vce(sat) is a maximum of 700 mV at a base current of 50 mA and collector current of 500 mA — that is the worst-case drop when the transistor is fully on. For a 500 mA load, that 700 mV drop means the transistor dissipates about 350 mW under that condition, which exceeds the 250 mW maximum power rating of the package. In practice, a design should not hold the transistor at that saturation point continuously; it is sized for intermittent or pulsed loads. The collector cutoff current is a maximum of 100 nA (ICBO), which is low enough that it will not leak into the load in off-state at room temperature, though at 150°C junction temperature it will rise — the datasheet's typical curve should be checked if the ambient is hot.