W91473 Datasheet, PDF (3/20 Pages) Winbond – 14-MEMORY TONE/PULSE SWITCHABLE DIALER WITH HANDFREE AND LOCK FUNCTION

W91473 SERIES
PIN DESCRIPTION
SYMBOL
Column-
Row
Inputs
22-PIN
1−7
&
18−22
24-PIN
1−7
&
20−24
XT, XT
9, 10
T/P
11
MUTE
9, 10
11
DP
13
15
MODE
15
17
HKS
12
14
28-PIN
1−8
&
24−28
11, 12
13
17
19
16
I/O
FUNCTION
I The keyboard input may be used with
either the standard 7 × 5 keyboard or an
inexpensive single contact (form A)
keyboard. Electronic input with µC can
also be used.
A valid key entry is defined by a single
row being connected to a single column.
I, O A built-in inverter provides oscillation with
an inexpensive 3.579545 MHz crystal or
ceramic resonator.
O _{The T/P MUTE is a conventional CMOS}
N-channel open drain output. The output
transistor is switched on during pulse and
tone mode dialing sequence and flash
break. Otherwise, it is switched off.
O N-channel open drain dialing pulse output
(Figure 1).
Flash key causes DP to go active when in
pulse mode and tone mode.
I Pulling mode pin to VSS places the dialer
in tone mode.
Pulling mode pin to VDD places the dialer
in pulse mode (10 ppS, M/B = 2:3).
Leaving mode pin floating places the
dialer in pulse mode (10 ppS, M/B = 1:2).
I Hook switch input.
HKS = 1: On-hook state. Chip in sleep
mode, no operation.
HKS = 0: Off-hook state. Chip enabled for
normal operation.
HKS pin is pulled to VDD by internal
resistor.
Publication Release Date: February 1995
-3-
Revision A3