Z9973

Pin Description [2]

Pin Number

Pin Name

PWR

I/O

Type

Pin Description

 

 

 

 

 

 

11

PECL_CLK

 

I

PU

PECL Clock Input.

 

 

 

 

 

 

12

PECL_CLK#

 

I

PD

PECL Clock Input.

 

 

 

 

 

 

9

TCLK0

 

I

PU

External Reference/Test Clock Input.

 

 

 

 

 

 

10

TCLK1

 

I

PU

External Reference/Test Clock Input.

 

 

 

 

 

 

44, 46, 48, 50

QA(3:0)

VDDC

O

 

Clock Outputs. See Table 2 for frequency selections.

 

 

 

 

 

 

32, 34, 36, 38

QB(3:0)

VDDC

O

 

Clock Outputs. See Table 2 for frequency selections.

 

 

 

 

 

 

16, 18, 21, 23

QC(3:0)

VDDC

O

 

Clock Outputs. See Table 2 for frequency selections.

 

 

 

 

 

 

29

FB_OUT

VDDC

O

 

Feedback Clock Output. Connect to FB_IN for normal operation. The

 

 

 

 

 

divider ratio for this output is set by FB_SEL(0:2). See Table 1. A bypass

 

 

 

 

 

delay capacitor at this output will control Input Reference/ Output Banks

 

 

 

 

 

phase relationships.

 

 

 

 

 

 

25

SYNC

VDDC

O

 

Synchronous Pulse Output. This output is used for system synchroni-

 

 

 

 

 

zation. The rising edge of the output pulse is in sync with both the rising

 

 

 

 

 

edges of QA (0:3) and QC(0:3) output clocks regardless of the divider ratios

 

 

 

 

 

selected.

 

 

 

 

 

 

42, 43

SELA(1,0)

 

I

PU

Frequency Select Inputs. These inputs select the divider ratio at QA(0:3)

 

 

 

 

 

outputs. See Table 2.

 

 

 

 

 

 

40, 41

SELB(1,0)

 

I

PU

Frequency Select Inputs. These inputs select the divider ratio at QB(0:3)

 

 

 

 

 

outputs. See Table 2.

 

 

 

 

 

 

19, 20

SELC(1,0)

 

I

PU

Frequency Select Inputs. These inputs select the divider ratio at QC(0:3)

 

 

 

 

 

outputs. See Table 2.

 

 

 

 

 

 

5, 26, 27

FB_SEL(2:0)

 

I

PU

Feedback Select Inputs. These inputs select the divide ratio at FB_OUT

 

 

 

 

 

output. See Table 1.

 

 

 

 

 

 

52

VCO_SEL

 

I

PU

VCO Divider Select Input. When set LOW, the VCO output is divided by

 

 

 

 

 

2. When set HIGH, the divider is bypassed. See Table 1.

 

 

 

 

 

 

31

FB_IN

 

I

PU

Feedback Clock Input. Connect to FB_OUT for accessing the

 

 

 

 

 

phase-locked loop (PLL).

 

 

 

 

 

 

6

PLL_EN

 

I

PU

PLL Enable Input. When asserted HIGH, PLL is enabled. And when LOW,

 

 

 

 

 

PLL is bypassed.

 

 

 

 

 

 

7

REF_SEL

 

I

PU

Reference Select Input. When HIGH, the crystal oscillator is selected. And

 

 

 

 

 

when LOW, TCLK (0,1) is the reference clock.

 

 

 

 

 

 

8

TCLK_SEL

 

I

PU

TCLK Select Input. When LOW, TCLK0 is selected and when HIGH TCLK1

 

 

 

 

 

is selected.

 

 

 

 

 

 

2

MR#/OE

 

I

PU

Master Reset/Output Enable Input. When asserted LOW, resets all of the

 

 

 

 

 

internal flip-flops and also disables all of the outputs. When pulled HIGH,

 

 

 

 

 

releases the internal flip-flops from reset and enables all of the outputs.

 

 

 

 

 

 

14

INV_CLK

 

I

PU

Inverted Clock Input. When set HIGH, QC(2,3) outputs are inverted. When

 

 

 

 

 

set LOW, the inverter is bypassed.

 

 

 

 

 

 

3

SCLK

 

I

PU

Serial Clock Input. Clocks data at SDATA into the internal register.

 

 

 

 

 

 

4

SDATA

 

I

PU

Serial Data Input. Input data is clocked to the internal register to

 

 

 

 

 

enable/disable individual outputs. This provides flexibility in power

 

 

 

 

 

management.

 

 

 

 

 

 

17, 22, 28,

VDDC

 

 

 

3.3V Power Supply for Output Clock Buffers.

33,37, 45, 49

 

 

 

 

 

 

 

 

 

 

 

13

VDD

 

 

 

3.3V Supply for PLL.

 

 

 

 

 

 

1, 15, 24, 30,

VSS

 

 

 

Common Ground.

35, 39, 47, 51

 

 

 

 

 

 

 

 

 

 

 

Note:

2.A bypass capacitor (0.1 F) should be placed as close as possible to each positive power (< 0.2”). If these bypass capacitors are not close to the pins, their high-frequency filtering characteristics will be cancelled by the lead inductance of the traces.

Document #: 38-07089 Rev. *D

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Cypress Z9973 manual Pin Description