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Communication ICs
Pulse / tone dialer for telephone set
BU8307CS / BU8307CF
The BU8307CS and BU8307CF are large scale integrated circuits with a pulse dialer and tone dialer integrated on a
single chip. These products are capable of dialing in either pulse or tone mode, and can redial up to 32 digits.
Applications
Telephones and cordless telephones
Features
1) The chip includes both a pulse and tone dialer, mak-
ing it possible to dial in either pulse or tone mode.
2) A wide operating voltage range enables direct pow-
ering by line current. The voltage range guaranteed
for both pulse and tone dialing is 2.5V to 5.5V.
3) A built-in memory enables redialing of up to 32 digits.
Note: In tone mode, the memory itself uses one digit,
so please be aware that a maximum of 31 digits can
be redialed.
4) The chip conforms to the standards of Japan, Ameri-
ca, Canada, England, Korea, Taiwan, and Australia.
5) The VDD power supply voltage is independent of the
DTMF output level.
6) There is little deviation in the frequency dividing for
the DTMF output frequency. The maximum on the +
side is + 0.15%, and on the - side is – 0.08%.
Block diagram