W91570DN SERIES
- 4 -
Pin Description, continued
SYMBOL
PIN NO.
I/O
FUNCTION
HFI
, HFO
37, 17
I,
O
Handfree control pins. A low pulse on the
HFI
input pin toggles
the handfree control state.
Status of the handfree control is listed in the following table:
CURRENT STATE
Input
HFO
Dialing
High
Yes
On Hook
High
Low
No
Off Hook
High
Low
Yes
On Hook
Off Hook
Low
Yes
Off Hook
Low
On Hook
Low
No
Off Hook
High
On Hook
High
Yes
Low
Hook SW.
HFO
NEXT STATE
HFI
HFI
HFI
The
HFI
pin is pulled to V
DD
by internal resistor.
Detailed timing diagrams are shown in Figure 4(a), 4(b).
DP
/
C10
18
O
This pin is a CMOS N-channel open drain output. The flash key
will cause
DP
/
C10
to go active in either pulse mode or tone
mode. In lock mode, the
DP
/
C10
keeps low for 300 mS during
off-hook delay time (If first off-hook occured after power-on
reset, the
DP
/
C10
will keep high for 100ms then go low 200
mS. It will be recovered when first key-in was accepted). The
timing diagram is shown as Figure 1(a), 1(b), 1(c), 1(d).
DTMF
12
O
In pulse mode, this pin remains in low state at all times.
In tone mode, it will output a dual or single tone. Detailed timing
diagram for tone mode is shown in Figure 2(a), 2(b), 2(c), 2(d).
Specified
Actual
Error %
OUTPUT FREQUENCY
R1
R2
R3
R4
C1
C2
C3
697
770
852
941
1209
1336
1477
699
766
848
948
1216
1332
1472
+0.28
-0.52
-0.47
+0.74
+0.57
-0.30
-0.34
MODE
19
I
Pulling the mode pin to V
SS
places the dialer in tone mode.
Pulling the mode pin to V
DD
places the dialer in pulse mode
and the dialing rate is 10 ppS.
Floating the mode pin places the dialer in pulse mode and the
dialing rate is 20 ppS.
electronic components distributor
