METHODS AND STRUCTURES TO GENERATE ON/OFF KEYED CARRIER SIGNALS FOR SIGNAL ISOLATORS

摘要

An oscillator for a signal isolator system includes a capacitor and an inductor connected in parallel, two pairs of cross-coupled switches and a control switch. The capacitor, the inductor and the cross-coupled switches form an oscillator. The control switch controls operation of the oscillator between an ON state and an OFF state in response to a data signal to be communicated across an isolation barrier. The inductor may be formed from a winding of an isolation transformer, which reduces component count as compared to a system that provides a separate inductor. Other embodiments may include a current-supplying kickstart circuit and a shorting transistor that can speed transition between the ON and OFF states.

主权项

1. A transmitter system for a signal isolator system, comprising:
an oscillator circuit coupled to an isolator device, a control switch, coupled between the oscillator circuit and a voltage supply having an input for an input signal to be transmitted by the system; and a means for accelerating transition of the oscillator circuit on a transition between an ON state and an OFF state as determined by the input signal.