MT8888CE1 Zarlink, MT8888CE1 Datasheet - Page 11

• Manufacturer Part Number: MT8888CE1
• Description: DTMF TXRX 3.58MHz CMOS 5V 20-Pin PDIP Tube
• Manufacturer: Zarlink

Specifications of MT8888CE1

• Package: 20PDIP
• Operating Frequency: 3.58 MHz
• Typical Supply Current: 7 mA
• Typical Operating Supply Voltage: 5 V
• Minimum Operating Supply Voltage: 4.75 V
• Maximum Operating Supply Voltage: 5.25 V

9.0
A single tone mode is available whereby individual tones from the low group or high group can be generated. This
mode can be used for DTMF test equipment applications, acknowledgment tone generation and distortion
measurements. Refer to Control Register B description for details.
10.0
The MT8888C is capable of producing precise tone bursts with minimal error in frequency (see Table 2). The
internal summing amplifier is followed by a first-order lowpass switched capacitor filter to minimize harmonic
components and intermodulation products. The total harmonic distortion for a single tone can be calculated using
Equation 1, which is the ratio of the total power of all the extraneous frequencies to the power of the fundamental
frequency expressed as a percentage.
The Fourier components of the tone output correspond to V
harmonic distortion for a dual tone can be calculated using Equation 2. V
amplitude and high group amplitude, respectively and V
internal switched-capacitor filter following the D/A converter keeps distortion products down to a very low level as
shown in Figure 10.
Single Tone Generation
Distortion Calculations
Table 2 - Actual Frequencies Versus Standard Requirements
ACTIVE
INPUT
H1
H2
H3
H4
L1
L2
L3
L4
Figure 11 - Equation 1. THD (%) For a Single Tone
THD (%) = 100
THD (%) = 100
Figure 12 - Equation 2. THD (%) For a Dual Tone
SPECIFIED
OUTPUT FREQUENCY (Hz)
1209
1336
1477
1633
697
770
852
941
Zarlink Semiconductor Inc.
MT8888C
V
2
2L
V
V
2
11
+ V
2
2
IMD
3H
2f
2
2f
V
+ V
+ .. V
3L
2
.... V
V
is the sum of all the intermodulation components. The
L
+ .... V
2
fundamental
ACTUAL
+ V
3f
2
1215.9
1331.7
1471.9
1645.0
699.1
766.2
847.4
948.0
nH
+ V
nf
2
H
+ V
2
2
as measured on the output waveform. The total
nL
4f
2
+ .... V
+ V
IMD
2
2H
2
L
+
nf
and V
%ERROR
+0.30
+0.74
+0.57
+0.73
-0.49
-0.54
-0.32
-0.35
H
correspond to the low group
Data Sheet