To provide a drive control apparatus which can turn off an output transistor reliably when it is not necessary to operate it, in a configuration that a communication signal is transmitted by driving the output transistor based on a trapezoidal wave voltage signal.
In a transceiver IC 20, the base of the output transistor Q14 is connected on the side of a transistor Q13 of a current mirror circuit 33 which composes a drive circuit 34 and a trapezoidal wave voltage signal is supplied. A transistor Q11 which composes the current mirror circuit 33 is equipped with a constant current circuit 35 for supplying a base current, and when a high level signal is output on a communication line 3, the circuit 35 is turned off.
COPYRIGHT: (C)2007,JPO&INPIT
ASADA TADATOSHI
UEDA SUSUMU
TOYODA HIROICHI
| JP2005039543A | 2005-02-10 | |||
| JP2004289597A | 2004-10-14 | |||
| JP2004534423A | 2004-11-11 | |||
| JP2004228859A | 2004-08-12 |
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