W91824N
Description
The W91820N is a series of tone/pulse switchable telephone dialers with 13 memory, keytone, hold, lock, and handfree dialing control features.
Key Features
- In normal operation, any single button can be pushed to produce dual tone, pulses, or functions
- Activation of two or more buttons will result in no response except for a single tone
- XT 8 8 I A built-in inverter together with an inexpensive 3.579545 MHz crystal supplies the oscillator
- The oscillator stops when there is no keypad input
- The crystal frequency deviation is 0.02%
- Crystal oscillator output pin
- The T/P MUTE is a conventional CMOS N-channel open drain output
- The output transistor turns on with a low level during a dialing sequence (both pulse and tone mode)
- Otherwise, it is off
- Connecting the mode pin to VDD places the dialer in pulse mode with an M/B ratio of 40:60
