M-959

M-959 Dial Pulse Counter and Hook Status Monitor Features Time-guarded dial pulse counting 10 or 20 PPS dialing speeds pin selectable Tri-state data outputs Valid data output strobe Data strobe control for use in interrupt-driven environments Independent hook status monitoring Low-power CMOS construction Description The M-959 is a low-power dial pulse counter and hook status monitor. Contained in a 14-pin package, the M-959 requires no external components except a single 3.579 MHz television color burst crystal. The M-959 is typically connected to a loop current sensing circuit, which is connected in series with the voice pair (Tip and Ring) of a telephone line. The M959 receives pulses from the loop current sense circuit and translates them into logic level outputs indicating hook status and decoded dialed digits. Logic inputs to the M-959 select dialed digit speeds and control Data and Strobe outputs supporting bus interrupt driven implementations. Pin Diagram Ordering Information Part # M-959 Description 14-pin plastic DIP Block Diagram DS-M959-R3 www.clare.com 1 M-959 Absolute Maximum Ratings are stress ratings. Stresses in excess of these ratings can cause permanent damage to the device. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this data sheet is not implied. Exposure of the device to the absolute maximum ratings for an extended period may degrade the device and effect i...