AC Characteristics

DESCRIPTION

NAME

SYMBOL

MIN

TYP

MAX

UNITS

Reference oscillator value (Note 1)

Reference

frequency

1

14.31818

60

MHz

Reference period

16.6

1000

ns

Duty cycle for the input oscillator

Input duty cycle

25%

75%

Output oscillator values

Output clock

periods

8.33

(120 MHz)

2564

(390 kHz)

ns

Duty cycle for the output oscillators

(Note 2)

Output duty cycle

45%

55%

Rise time for the output oscillators

into a 25pF load

Rise times

3

ns

Fall time for the output oscillators

into a 25pF load

Fall times

3

ns

Old frequency output

freq1 output

New frequency output

freq2 output

Time clock output remains high while

output muxes to reference frequency

0.5

1.5

ns

Interval for serial programming and

for VCO changes to settle (Note 3)

Time-out interval

25

10

ms

Time clock output remains high while

output muxes to new frequency value

0.5

1.5

ns

Time for the output oscillators to go

into tristate mode after OUTDIS-

signal assertion

Tristate

12

ns

Time for the output oscillators to

recover from tristate mode after

OUTDIS-signal goes high

CLK valid

12

ns

Time for power-down mode of

operation to take effect

Power-Down

12

ns

Time for recovery from power-down

mode to a valid CLK

Power-Up

12

ns

Time for MCLK to go high after

PWRDWN is asserted high

MCLKOUT high

ns

signal at output

MCLKOUT delay

0.5

1.5

ns

Clock period of serial clock

2

2ms

Set-up time

20

ns

Hold time

10

ns

Load command

ns

Notes:

1.

For reference frequencies other than 14.81818 MHz, the pre-loaded ROM frequencies will shift proportionally.

2.

3.

If the interval is too short, see the time-out interval section in the control register definition.

ICS82C404

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