| 摘要 |
<p>The drivers of a bus are provided with an internal positive voltage clamp, which insures that large positive voltage waves will not be launched down the bus. By increasing the output conductance of the driver when larger than desired voltage is detected at its output, higher voltage waves are prevented from developing on the bus. The circuit comprises a first NPN bipolar transistor (T1SC) having its collector connected to said bus, its emitter connected through an impedance device to a low reference potential, and its base connected through a clamping device (D1, D2) to said collector thereof; and a second NPN bipolar transistor device (T2SC) having its collector connected through an impedance to a relatively high reference potential (VCC), its emitter connected to said base of said first NPN bipolar transistor (T1SC) and its emitter connected through an impedance to said low reference potential, and its base connected to an input signal source (IN). The voltage level on said bus being limited by active clamping of said driver circuit, to improve bus performance.</p> |
