8

3sOE

ILVTTL

Synchronous Output Enable.

The sOE input is used to synchronously enable/

disable the output clocks. Each clock output that is controlled by the sOE pin is

disables all clocks except 2Q0 and 2Q1. When disabled, 1Q0, 1Q1, 3Q0, and 3Q1

The disabled state of 4Q0 and 4Q1 is dependent upon the state of PE/HD and 4F[1:0].

The following table illustrates the disabled state of bank 4 outputs as they are

controlled by the state of PE/HD and 4F[1:0].

PE/HD

4F[1:0]*

4Q0

4Q1

LOW

HH

LOW

LOW

MID

HH

HIGH

HIGH

HIGH

HH

HIGH

HIGH

*All other combinations of 4F[1:0] will result in 4Q0 and 4Q1 disabling into

HIGH

individual output enable/disable controls for each output bank, excluding bank 2.

operating modes.

1, 2, 24,

25, 26, 27,

47, 48

nF[1:0]

I

3-Level

Output divider and phase skew selection for each output bank.

Please see Tables 3, 4, 5, 6, and 9 for a complete explanation of the nF[1:0] control

functions and their effects on output frequency and skew.

46

FS

I

3-Level

VCO operating frequency range selection.

Please see Tables 7 and 8.

8, 9, 17,

18, 31, 32,

41, 42

nQ[1:0]

O

LVTTL

Four clock banks of two outputs each.

Please see Table 6 for frequency settings and Table 9 for skew settings.

22, 23

DS[1:0]

I

3-Level

Feedback input divider selection.

Please see Table 1 for a summary of the feedback input divider settings.

5

PE/HD

I

3-Level

Positive/negative edge control and high/low output drive strength selection.

The

PE portion of this pin controls which edge of the reference input synchronizes the

clock outputs. The HD portion of this pin controls the drive strength of the output

clock buffers. The following table summarizes the effects of the PE/HD pin during

normal operation.

PE/HD

Synchronization

Output Drive Strength

LOW

Negative Edge

Low Drive

MID

Positive Edge

High Drive

HIGH

Positive Edge

Low Drive

Low drive strength outputs provide 12mA of drive strength while the high drive

condition results in 24mA of current drive. Output banks operating from a 2.5V

power supply guarantee a high drive of 20mA.

Flatpack

Pin No.

Name

I/O

Type

Description