Ring detection and snoop circuit

摘要

A ring detect circuit is shown that includes a regenerative latch configured to be coupled to a telephone line. The regenerative latch is configured to generate a fast transient signal in response to a ring signal on the telephone line. The latch is coupled to an isolation transformer through a capacitor. The fast transient passes across the capacitor and through the transformer. A comparator detects the fast transient and, responsive thereto, generates a ring detect signal.