IDT®

Programmable System Clock Chip for ATI RD790-K8TM Based Systems

1393—01/28/14

9LPRS477C

Programmable System Clock Chip for ATI RD790 - K8TM based Systems

21

Electrical Characteristics - USB - 48MHz

PARAMETER

SYMBOL

CONDITIONS*

MIN

TYP

MAX

UNITS NOTES

Long Accuracy

ppm

see Tperiod min-max values

-100

100

ppm

1,2

Clock period

T

period

48.00MHz output nominal

20.8229

20.8344

ns

2

Clock Low Time

T

low

Measure from< 0.6V

9.3750

11.4580

ns

2

Clock High Time

T

high

Measure from> 2.0V

9.3750

11.4580

ns

2

Output High Voltage

V

OH

I

OH = -1 mA

2.4

V

1

Output Low Voltage

V

OL

I

OL = 1 mA

0.55

V

1

V

OH @MIN = 1.0 V

-33

mA

1

V

OH@MAX = 3.135 V

-33

mA

1

V

OL @ MIN = 1.95 V

30

mA

1

V

OL @ MAX = 0.4 V

38

mA

1

Rise Time

t

rUSB

V

OL = 0.4 V, VOH = 2.4 V

0.5

1.5

ns

1

Fall Time

t

fUSB

V

OH = 2.4 V, VOL = 0.4 V

0.5

1.5

ns

1

Duty Cycle

d

t1

V

T = 1.5 V

45

55

%1

Group Skew

t

skew

V

T = 1.5 V

250

ps

1

Jitter, Cycle to cycle

t

jcyc-cyc

V

T = 1.5 V

130

ps

1,2

*TA = 0 - 70°C; Supply Voltage VDD = 3.3 V +/-5%, CL = 5pF w ith Rs = 33Ω (unless otherw ise specified)

1

Guaranteed by design and characterization, not 100% tested in production.

2

ICS recommended and/or chipset vendor layout guidelines must be follow ed to meet this specification

Output Low Current

I

OL

Output High Current

I

OH

Electrical Characteristics - REF-14.318MHz

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS Notes

Long Accuracy

ppm

see Tperiod min-max values

-300

300

ppm

1,2

Clock period

T

period

14.318MHz output nominal

69.8270

69.8550

ns

2

Clock Low Time

T

low

Measure from< 0.6V

30.9290

37.9130

ns

2

Clock High Time

T

high

Measure from> 2.0V

30.9290

37.9130

ns

2

Output High Voltage

V

OH

I

OH = -1 mA

2.4

V

1

Output Low Voltage

V

OL

I

OL = 1 mA

0.4

V

1

Output High Current

I

OH

V

OH @MIN = 1.0 V,

V

OH@MAX = 3.135 V

-29

-23

mA

1

Output Low Current

I

OL

V

OL @MIN = 1.95 V,

V

OL @MAX = 0.4 V

29

27

mA

1

Rise Time

t

r1

V

OL = 0.4 V, VOH = 2.4 V

1

1.5

ns

1

Fall Time

t

f1

V

OH = 2.4 V, VOL = 0.4 V

1

1.5

ns

1

Skew

t

sk1

V

T = 1.5 V

250

ps

1

Duty Cycle

d

t1

V

T = 1.5 V

45

55

%

1

Jitter

t

jcyc-cyc

V

T = 1.5 V

200

ps

1

*TA = 0 - 70°C; Supply Voltage VDD = 3.3 V +/-5%, CL = 5pF w ith Rs = 33Ω (unless otherw ise specified)

1

Guaranteed by design and characterization, not 100% tested in production.

2

All Long TermAccuracy and Clock Period specifications are guaranteed assuming that REFOUT is at 14.31818MHz