System for switching between stand by and wake up for a data processing unit and an analog switch

摘要

A switching unit (21) lies between the processor (22) and an analogue switch (23). The processor has an output (27) controlling the state of the device via a semiconductor switch (28) between the output of the analogue switch and comparator (29) which compares this output with a reference to deliver a signal to the operational information input. The processor output equally controls a second semiconductor switch (30) between the analogue switch and an analogue information input (24) of the processor. The analogue switch has a fault detection resistor (31) between the output (26a) and the earth via a third semiconductor switch (32) controlled by the processor.