mail us  |  mail this page

contact us
training  | 
tech stuff  | 

Tech Stuff - DTMF Tones

The following table defines the tones used in DTMF (see ANSI T1.401-1988 Section 7.2):

Each tone is composed of a low-high pair of frequencies as defined in the table:

DTMF Char Low (Hz) high (Hz)
1 697 1209
2 697 1336
3 697 1477
4 770 1209
5 770 1336
6 770 1477
7 852 1209
8 852 1336
9 852 1477
* (star) 941 1209
0 941 1336
# (num) 941 1477
A 697 1633
B 770 1633
C 852 1633
D 941 1633

DTMF Tone Power is given by the following table:

Power dBm
Max. Power per tone +1.0
Min. Power per Low freq. tone -10.5
Min. power per High freq. tone -8.5

Notes: frequency limit is +- 1.5%, difference in power between the low and high frequencies should not exceed 3dB and the power of the high frequency tone should equal or exceed the low frequency tone.



Problems, comments, suggestions, corrections (including broken links) or something to add? Please take the time from a busy life to 'mail us' (at top of screen), the webmaster (below) or info-support at zytrax. You will have a warm inner glow for the rest of the day.

Tech Stuff

RSS Feed Icon

If you are happy it's OK - but your browser is giving a less than optimal experience on our site. You could, at no charge, upgrade to a W3C standards compliant browser such as Firefox

Search

web zytrax.com

Share

Icons made by Icomoon from www.flaticon.com is licensed by CC 3.0 BY
share page via facebook tweet this page

Page

email us Send to a friend feature print this page Display full width page Decrease font size Increase font size

Standards

ISO (International)
IEC (International)
ANSI (US)
DIN (Germany)
ETSI (EU)
BSI (UK)
AFNOR (France)

Telecom

TIA (US)
ECIA (US)
ITU (International)
IEEE (US)
ETSI (EU)
OFCOM (UK)

Internet

IETF
IETF-RFCs
IANA
ICANN
W3C

Electronics

JEDEC
ECIA (US)

Site

CSS Technology SPF Record Conformant Domain
Copyright © 1994 - 2024 ZyTrax, Inc.
All rights reserved. Legal and Privacy
site by zytrax
hosted by javapipe.com
web-master at zytrax
Page modified: January 20 2022.