gbell@pnet12.cts.com (Greg Bell) (01/28/89)
Are there any available chips to do both encoding AND decoding of DTMF in
the same DIP? Would save some board space.
If anyone from Teletone is on here, I would appreciate hearing from you
guys about this! Chances are, Teletone makes such a creature...
Greg Bell_________________________________________________________
Hardware hacker |
Electronics hobbyist | UUCP: uunet!serene!pnet12!gbell
EE major at UC San Diego |byron@pyr.gatech.EDU (Byron A Jeff) (01/28/89)
In article <350@serene.UUCP> gbell@pnet12.cts.com (Greg Bell) writes: > > > > > Are there any available chips to do both encoding AND decoding of DTMF in >the same DIP? Would save some board space. Silicon Systems Inc. has such a beast. It's called the SSI 20C90 DTMF transceiver with call progress detection. It generates and receives all 16 DTMF digits, has a micro interface and an "imprecise" call progress detector. The only external components are a 3.57 Mhz "colorburst" crystal and a resistor. It's a low power CMOS part in a 22 pin DIP. The call progress detector simply activates a signal when the tone is in the 305-640 hz band. It's up to the microprocessor to figure out what the signal means. Never used one of these but it looks like a nice part. > Greg Bell_________________________________________________________ I'm in no way associated with SSI except for being a satisfied customer. BAJ -- Another random extraction from the mental bit stream of... Byron A. Jeff Georgia Tech, Atlanta GA 30332 Internet: byron@pyr.gatech.edu uucp: ...!gatech!pyr!byron
mlt@quintro.UUCP (Michael L. Tanner) (01/31/89)
In article <350@serene.UUCP> gbell@pnet12.cts.com (Greg Bell) writes: > Are there any available chips to do both encoding AND decoding of DTMF in >the same DIP? Would save some board space. > Mitel makes the type of IC that you are looking for. The part is MT8880, and comes in a 20 pin DIP. It has a microprocessor bus interface and is relatively easy to interface to. The chip uses a standared 3.58 Mhz crystal. The last price that I know of is about $7.50 each. This is a 2 year old price, and that was when the chip first came out. I assume that the prices have dropped since then.
larry@kitty.UUCP (Larry Lippman) (02/04/89)
In article <350@serene.UUCP>, gbell@pnet12.cts.com (Greg Bell) writes: > Are there any available chips to do both encoding AND decoding of DTMF in > the same DIP? Would save some board space. Yup - they are generally referred to as "DTMF transceiver" circuits. Try the Silicon Systems SSI-20C90, which performs the above function for all 16 DTMF tone pairs. <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {att|hplabs|mtune|utzoo|uunet}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"