W91520N Datasheet, PDF (2/16 Pages) Winbond – TONE/PULSE DIALER WITH HANDFREE AND HOLD FUNCTION

PIN CONFIGURATIONS
W91520N SERIES
C1
1
C2
2
C3
3
C4
4
H/P MUTE
5
VSS
6
XT
7
XT
8
T/P MUTE
9
18
R4
17
R3
16
R2
15
R1
14
VDD
13
MODE
12
DTMF
11
DP/C5
10
HKS
W91520N/W91521N
C1
1
C2
2
C3
3
C4
4
H/P MUTE
5
VSS
6
XT
7
XT
8
T/P MUTE
9
HFI
10
20
R4
19
R3
18
R2
17
R1
16
VDD
15
MODE
14
DTMF
13
DP/C5
12
HKS
11
HFO
W91520AN/W91521AN
PIN DESCRIPTION
SYMBOL 18-PIN
Column-
Row
Inputs
1−4
&
15−18
XT, XT
7, 8
T/P MUTE
9
MODE
13
20-PIN I/O
FUNCTION
1−4
&
17−20
The keyboard inputs may be used with either a
I ^{standard 5 × 5 keyboard or an inexpensive single}
contact (Form A) keyboard. Electronic input from a µC
can also be used. A valid key-in is defined as a single
row being connected to a single column.
7, 8 I, O A built-in inverter provides oscillation with an
inexpensive 3.579545 MHz crystal or ceramic
resonator.
9
O _{The T/P MUTE is a conventional CMOS N-channel}
open drain output.
The output transistor is switched on during dialing
sequence, one-key redial break, and flash break time.
Otherwise, it is switched off.
15
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; 20 ppS for W91521N/521AN, M/B =
40:60).
Floating mode pin places the dialer in pulse mode
(10 ppS; 20 ppS for W91521N/521AN, M/B =
33.3:66.7).
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