ISO
2
-CMOS
MT8870D-1 AC Electrical Characteristics
-
Characteristics
1
Valid input signal levels (each
tone of composite signal)
Input Signal Level Reject
Negative twist accept
Positive twist accept
Frequency deviation accept
Frequency deviation reject
Third zone tolerance
Noise tolerance
Dial tone tolerance
±1.5%± 2 Hz
±3.5%
-18.5
-12
+22
Sym
MT8870D/MT8870D-1
V
DD
=5.0V±5%, V
SS
=0V, -40°C
≤
T
O
≤
+85°C , using Test Circuit shown in
Figure 10.
Min
-31
21.8
-37
10.9
Typ
‡
Max
+1
869
Units
dBm
mV
RMS
dBm
mV
RMS
Notes*
Tested at V
DD
=5.0V
1,2,3,5,6,9
Tested at V
DD
=5.0V
1,2,3,5,6,9
2,3,6,9,13
2,3,6,9,13
2,3,5,9
2,3,5,9
2
3
4
5
6
7
8
9
8
8
dB
dB
dB
dB
dB
2,3,4,5,9,12
2,3,4,5,7,9,10
2,3,4,5,8,9,11
‡ Typical figures are at 25 °C and are for design aid only: not guaranteed and not subject to production testing.
*
NOTES
1. dBm= decibels above or below a reference power of 1 mW into a 600 ohm load.
2. Digit sequence consists of all DTMF tones.
3. Tone duration= 40 ms, tone pause= 40 ms.
4. Signal condition consists of nominal DTMF frequencies.
5. Both tones in composite signal have an equal amplitude.
6. Tone pair is deviated by ±1.5 %± 2 Hz.
7. Bandwidth limited (3 kHz ) Gaussian noise.
8. The precise dial tone frequencies are (350 Hz and 440 Hz) ± 2 %.
9. For an error rate of better than 1 in 10,000.
10. Referenced to lowest level frequency component in DTMF signal.
11. Referenced to the minimum valid accept level.
12. Referenced to Fig. 10 input DTMF tone level at -25dBm (-28dBm at GS Pin) interference frequency range between 480-3400Hz.
13. Guaranteed by design and characterization.
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