SC91415CK Datasheet, PDF (15/23 Pages) Silan Microelectronics Joint-stock – TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE AND DUAL-TONE MELODY

Silan
Semiconductors
SC91415 SERIES
J) Ring detector
The Ring detector is designed to prevent illegal dialing from pocket dialer. Following the procedures ( i,ii,iii ), this
dialer will detect DRING pin to control RMUTE output level. If DRING is detected a “Low” level, the
RMUTE stays “High impedance”. If DRING is detected a “High” level, the RMUTE will output “Low” until
keyboard entry. In actual application of the RMUTE pin is recommended connection to microphone of the phone
handset to prevent that the dialing signal (DTMF) is coupling by the Microphone of the phone handset. (such as
pocket dialer)
i. In idle state, HKS is from “High” to “Low” (pick up handset action).
ii. In idle state, turn on handfree function.
iii. The flash operation ( F key ).
TIMING DIAGRAMS
HKS
KEY IN
Tdb
KT
XMUTE
HDO
SDO
PO
DTMF
OSC.
2
3
Tkt
Tm
Tidp
TbTm Tb Tm
Tidp
Tdly
Pulse mode operating timing
Hi-impedance
HKS
KEY IN
KT
XMUTE
HDO
SDO
PO
DTMF
OSC.
2
3
Tdb
Td
Titp
DTMF mode operating timing
Titp
Hi-impedance
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 2.0
2001-11-13
15