MT8888C/MT8888C-1

4-105

† Characteristics are over recommended operating conditions unless otherwise stated

NOTES: 1) dBm=decibels above or below a reference power of 1 mW into a 600 ohm load.

2) Digit sequence consists of all 16 DTMF tones.

3) Tone duration=40 ms. Tone pause=40 ms.

4) Nominal DTMF frequencies are used.

5) Both tones in the composite signal have an equal amplitude.

6) The tone pair is deviated by ± 1.5%±2 Hz.

7) Bandwidth limited (3 kHz) Gaussian noise.

8) The precise dial tone frequencies are 350 and 440 Hz (±2%).

9) Guaranteed by design and characterization. Not subject to production testing.

10) Referenced to the lowest amplitude tone in the DTMF signal.

11) For guard time calculation purposes.

Characteristics

Sym

Min

Max

Units

Conditions

1RD/WR clock frequency

4.0

MHz

Figure 16

2RD/WR cycle period

250

ns

Figure 16

3RD/WR rise and fall time

20

ns

Figure 16

4

Address setup time

23

ns

Figures 17 & 18

5

Address hold time

26

ns

Figures 17 & 18

6

Data hold time (read)

22

ns

Figures 17 & 18

7RD to valid data delay (read)

100

ns

Figures 17 & 18

8RD, WR pulse width low

150

ns

Figures 16, 17 & 18

9RD, WR pulse width high

100

ns

Figures 16, 17 & 18

10

Data setup time (write)

45

ns

Figures 17 & 18

11

Data hold time (write)

10

ns

Figures 17 & 18

12

Input Capacitance (data bus)

5pF

13

Output Capacitance (IRQ/CP)

5pF