dialerf chip NTE1691

[lerameur]

Hello,

I would like to use a dialer chip the NTE1691. Can some tell me how to use the RC pin, There a three pins used as reference frequency, The datasheet does not say how to hook them up (RC), and also it do not talk about the output frequencies for dialing.
http://www.datasheetcatalog.com/datasheets_pdf/N/T/E/1/NTE1691.shtml
anyone has a circuit configuration.. a schematic or a better datasheet
This is the only chip I can get in the montreal region. To my surprise they(any dialer chip) are very rare

thank you
ken

[skimask]

To my surprise they(any dialer chip) are very rare
Don't know much about the nte1691, but, you know, the PIC and PBP can be very effectively used as a dialing tone generator, as well as an effective keypad scanner, all at the same time, all packed into an 18 pin PIC.
A quick look in the PBP manual shows that FREQOUT can easily produce 2 frequencies, and the BUTTON command can check individual switches, or there are more than a few keypad scanning routines here on the forums.

[mister_e]

Maybe why DTMFOUT exist in PBP :D


LR40992 seems to be one of the original equivalent
http://www.datasheetcatalog.com/datasheets_pdf/L/R/4/0/LR40992.shtml

Not something i would use myself.

[lerameur]

thanks, thats the datasheet, I needed. I will try using only a microcontroller at first. I just thought is might be safer to use a dialer chip. both for isolation and... I guess thats it :)
I found earlier this very simple circuit:
http://ourworld.compuserve.com/homepages/Bill_Bowden/autocall.htm

[mister_e]

KingGeorge and MasterVox should have a sh!t load of those telephone line transformer in stock... under their usual 10-15 feet of dust ;)

Not sure if i would use the schematic AS-IS for PBP. Worth a try.

Use 20MHz for better results in PBP.

[lerameur]

master Vox is the only that has dialers..
they also have those two cheaper dialers at 2$ T25089 MK50981N.
but there are no pictures and I have not seen any datasheet.
can you find any?
Google got me only 162 results without datasheet.
I learned that NTE chips are replacement chips wow!

[mister_e]

and in the good ol' day it was ECG :D

In montreal area you can also find NTE at Raybel Electronique and really few at Active Électronique.

MK50981 = ECG1693 = NTE1693 = LR40891

T25089 = S25089 = KS5808 = LR4089 = MK5089 = SBA5089 = T25089 = UM95089 = NTE1690
LR4089 http://www.datasheetarchive.com/pdf/2033097.pdf

To me NTE is more a last resort replacement part rather than a part... one reason why their documentation are a bit small....