MV5089
MV5089
DTMF GENERATOR
The MV5089 is fabricated using Plessey Semiconductors' ISO-
CMOS high density technology and offers low power and wide
voltage operation.
An inexpensive 3.
58MHz TV crystal completes the reference oscillator.
From this frequency are derived 8 different sinusoidal frequencies which, when appropriately mixed, provide Dual-Tone MultiFrequency (DTMF) tones.
Inputs are compatible with a standard 2-of-8 active-low keyboard and the keyboard entries determine the correct division of the reference frequency by the row and column counters.
D-to-A conversion, using R-2R ladder networks, results in a 'staircase' approximation of a sinewave with low total distortion.
Frequenc...