General Description
The NT91315XL series are single-chip silicon gate CMOS integrated circuits with on-chip oscillators to be used with a 3.58 MHz crystal or ceramic resonator. They provide dialing pulse (DP) or dual tone multi-frequency (DTMF) dialing. A 24-key (5x5-1) matrix keyboard is used for either DP or DTMF mode. In on-chip RAM, up to 32 digits can be saved for both redial and save functions, and up to 16 digits can be saved for 3 direct emergency and 10 indirect dialing memory banks. In DTMF mode, a small minimum tone duration and minimum inter-tone pause allows for rapid dialing. Maximum tone duration depends on the key depression time in manual dialing.

FEATUREs
■ Tone/Pulse switchable
■ 32-digit redial memory
■ 32-digit save memory (DL version)
■ 3 emergency memory banks (16 digits each)
■ 10 indirect memory banks (16 digits each)
■ Flash, Pause, P®T can be saved as a digit in memory
■ Chain dialing allowed
■ None or (0) or (0, 9) or (0, 168) or all digits dialing inhibition (diode option) for PABX system or long distance dialing lock out
■ Pause time 2.2/3.6 sec selectable (diode option)
■ 3 pulse dialing number systems N/N+1/10-N (diode option)
■ Dialing rate 10pps, M/B ratio 2/3 & 1/2 selectable/dialing rate 10pps & 20pps selectable, M/B ratio 1/2 (diode option)
■ Hands-Free control function with debouncing (BL, CL & DL version)
■ Hold function with debouncing (CL & DL version)
■ Key-tone output for dialing access (DL version)
■ One-key redial (DL version)
■ Flash time 600ms, 300ms, 100ms (DL version)
■ Power-up reset circuit provided
■ Key release debouncing
■ 32-step synthetic tone output for low DTMF output harmonic distortion
■ 16/18/20/22-pin packages