M-959
Overview
- 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
