AC Electrical Characteristics at Ta = 25°C, VDD= 3 V, VSS= 0 V, f
OSC
= 4.194304 MHz
Note: 1. The dBm values are defined such that 0 dBm is the 1 mW power level for a 600 Ω load.
2. All 16 DTMF signals frequency
3. With a 40 ms DTMF signal period and a 40 ms pause period
4. Nominal DTMF signal frequencies
5. Low-group and high-group signal levels are the same.
6. DTMF signal frequency deviations within ±1.5% ± 2 Hz
7. Gaussian noise with a 0 to 3 kHz bandwidth
8. 350 and 440 Hz dial tone frequencies
9. Error rate of less than 1 error in 10,000 events
10.Referenced to the lowest component of the DTMF signal.
11.Twist =
Pin Assignment
High-frequency group tone level
Low-frequency group tone level
No. 5000-2/6
LC73881M
Parameter Symbol Conditions min typ max Unit
Input signal valid level — *1, 2, 3, 5, 6, 9 –45 –20 dBm
Positive twist accept — *2, 3, 6, 9, 11 ±10 dB
Frequency detection accept — *2, 3, 5, 9 ±1.5% ±2 Hz
Frequency rejection accept — *2, 3, 5 ±3.5 %
Third tone tolerance — *2, 3, 4, 5, 9, 10 –16 dB
Dial tone tolerance — *2, 3, 4, 5, 8, 9, 10 +22 dB
Noise tolerance — *2, 3, 4, 5, 7, 9, 10 –8 dB
Tone present detection time t
DP
See the timing chart. 3 20 ms
Tone absent detection time t
DA
See the timing chart. 0.5 20 ms
Tone duration accept t
REC
See the timing chart. 20 ms
Tone duration reject t
REC
See the timing chart. 45 ms
Inter-digit pause invalid time t
DO
See the timing chart. 20 ms
Inter-digit pause valid time t
ID
See the timing chart. 40 ms
Data shift speed — 1 MHz
Data output delay time t
PAD
See the ACK/SD timing chart 100 ns
Setup time delay t
DL
See the ACK/SD timing chart 4 µs
Data hold time t
DH
See the ACK/SD timing chart 30 ns
Oscillator frequency f
OSC
4.190109 4.194304 4.198498 MHz
Load capacitance C
XO
The OSCI and OSCO pins 30 pF