W91590 Datasheet, PDF (3/20 Pages) Winbond – 24-MEMORY TONE/PULSE SWITCHABLE DIALER WITH HANDFREE, HOLD AND LOCK FUNCTIONS

W91590 SERIES
PIN DESCRIPTION
SYMBOL 22-PIN 24-PIN
28-PIN I/O
FUNCTION
Column-
Row
Inputs
1−7
&
18−22
1−7
&
20−24
1−8
&
24−28
I The keyboard input may be from either the
standard 9 × 5 keyboard or an inexpensive
single contact (form A) keyboard. Electronic
input from a µC can also be used.
A valid key entry is defined by a single row
being connected to a single column.
XT, XT ^{9, 10}
9, 10
11, 12
I, O A built-in inverter provides oscillation with an
inexpensive 3.579545 MHz crystal or
ceramic resonator.
T/P
11
11
MUTE
13
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.
HPM
-
-
MUTE
23
O The HPM MUTE is a conventional inverter
output. During pulse dialing, flash, hold, and
mercury mute functions, this pin will output
an active high. It remains in a low state at all
other times.
MODE
15
17
19
I Pulling mode pin to VSS places the dialer in
tone mode.
Pulling mode pin to VDD places the dialer in
pulse mode (M/B = 2:3).
Leaving mode pin floating places the dialer
in pulse mode (M/B = 1:2).
HKS
12
14
16
I Hook switch input.
HKS = 1: On-hook state. Chip in sleeping
mode, no operation.
HKS = 0: Off-hook state. Chip enabled for
normal operation.
HKS pin is pulled to VDD by internal resistor.
DP /C9
13
15
17
O N-channel open drain dialing pulse output
(Figure 1).
Flash key causes DP to go active when in
pulse mode and tone mode.
NC
17
19
22
- No connection.
(W91590) (W91590A) (W91590B/C)
Publication Release Date: July 1995
-3-
Revision A3