MV5089 Zarlink Semiconductor, MV5089 Datasheet - Page 3

• Manufacturer Part Number: MV5089
• Description: Dtmf Generator
• Manufacturer: Zarlink Semiconductor

OUTPUT FREQUENCY
standard DTMF frequencies when a 3.58MHz crystal is used
as the reference.
synthesised using R-2R D-to-A converters (see Fig.3),
resulting in staircase approximations to a sinewave. An opamp
mixes these tones to produce a dual-tone waveform. Single
tone distortion is typically better than 7% and all distortion
components of the mixed dual-tone should be 30dB relative to
the strongest fundamental (column tone).
DISTORTION MEASUREMENTS
Where V2f --- Vnf are the Fourier components of the waveform.
THD for the dual tone is defined by:
2
Table 1 shows the output frequency deviation from the
The row and column output waveforms are digitally
THD for the single tone is defined by:
where
V
V
V
V
V
ROW
COL
2R
2C
IMD
—V
—V
is the sum of all intermodulation components.
is the column fundamental amplitude
is the row fundamental amplitude
nR
nC
are the Fourier component amplitudes of the row frequencies
are the Fourier component amplitudes of the column frequencies
a)
b)
V
V
Figure 3: Typical sinewave output (a) Row tones (b) Column tones
OUT
OUT
100 (
100 (
V
V
2
2R
2
2f
+ V
+ V
V
3R
2
2
3f
fundamental
+ V
+ V
Column
2
nR
V
Row
2
4f
+ V
ROW
2
+ ---- V
2C
2
+ V
+ V
f
f
f
f
f
f
f
f
Standard
1
2
3
4
5
6
7
8
2
nf
3C
2
DTMF
Table 1: Output frequency deviation
) %
(Hz)
COL
2
--- V
697
770
852
941
1209
1336
1477
1633
nc
2
+ V
Frequency Using
IMD
2
3.5795545 MHz
Tone Output
)
Crystal
701.3
771.4
857.2
935.1
1215.9
1331.7
1471.9
1645.0
t
t
from Standard
% Deviation
+0.62
+0.19
+0.61
-0.63
+0.57
-0.32
-0.35
+0.73
High
Group
Low
Group