W91810N Datasheet, PDF (4/26 Pages) Winbond – 23-MEMORY TONE/PULSE DIALER WITH HANDFREE, LOCK AND HOLD FUNCTIONS

W91810N SERIES
Pin Description, continued
SYMBOL 22-PIN 24-PIN 28-PIN I/O
FUNCTION
KT
6
6
7
O The key tone output is a conventional CMOS
(W91810N/81
0AN/812N/812
inverter. The key tone is generated when any valid
key is pressed; the KT pin generates a 1.2 KHz
AN/811AN/813
AN only)
square wave at 35 mS. When no key is pressed,
the KT pin remains in low state.
LOCK
6
6
7
I The function of this terminal is to prevent "0"
(W91810LN/
810ALN/
dialing and "9" dialing under PABX system long
distance call control. When the first key input after
811ALN only)
reset is 0 or 9, all key inputs, including the 0 or 9
key, become invalid and the chip generates no
output. The telephone is reinitialized by a reset.
The function of the LOCK pin is shown below:
LOCK PIN
V_DD
Floating
V_SS
FUNCTION
"0", "9" dialing inhibited
Normal dialing Mode
"0" dialing inhibited
H/P MUTE
7
7
8
I The H/P MUTE is a conventional inverter output.
During pulse dialing, flash break or hold period,
this output is active high; otherwise, it remains in
low state.
DP
13
15
18 O N-channel open drain dialing pulse output.
Flash key will cause DP to be active in either tone
mode or pulse mode.
In lock mode, the DP remains low for 300 mS
during off-hook delay time.
The timing diagram for pulse mode is shown in
Figure 1(a, b).
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