GENERAL DESCRIPTION
The W91570DN series ICs are Si-gate CMOS ICs that provide the signals needed for either pulse or tone dialing. They feature 23 number memories and a 16-digit LCD driver for displaying telephone numbers and calling time. A real time clock is included to display the time of day. The W91570DN series is fabricated using CMOS technology providing good performance in low voltage, low power applications.

FEATURES
• Three by 32 digits for redial, save and mercury memory
• Twenty by 16 digits for one-touch direct or two-touch indirect repertory memory
• Uses 6 x 10 keyboard
• Pause, Pulse-to-tone (*/T) and flash can be stored as a digit in memory
• Minimum tone output duration: 87 mS
• Minimum intertone pause: 87 mS
• Tone/Pulse mode pin selectable
• Make/Break ratio pin selectable
• Dialing rate (10 or 20 ppS) pin selectable
• Pause time (2.0 or 3.6 Sec) selectable by keypad
• Flash break time (100, 300, or 600 mS) selectable by keypad
• Built-in 12 or 16-digit LCD driver (1/4 duty, 1/3 bias) selectable by mask option
• Built-in calling timer from [00:00] to [59:59]
• Uses 3.579545 MHz TV quartz crystal or ceramic resonator
• Uses 32768 Hz crystal as RTC frequency base
• Packaged in 80-pin plastic QFP with RTC
• Provides one-key-redial and auto-redial functions
• Switchable 24-hour clock or 12-hour clock with p.m. mode
• 0 or 9 dialing inhibition pin for PABX systems or long distance dialing lock out
• On-hook debounce: 150 msec in normal mode and 20 msec in lock mode
• Off-hook delay 300 mS in lock mode (i.e. DP will keep low for 300 mS while off hook)
• First key-in delay: 300 msec in lock mode
• MUTE key for speech mute
• Cascade and mixed dialing allowed