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Z9975 Datasheet, PDF (1/8 Pages) Cypress Semiconductor – 3.3V, 150MHz, Multi-Output Zero Delay Buffer
Product Features
• Output Frequency up to 150MHz
• Supports Power PC TM, and Pentium TM Processors
• 15 Clock Output: Frequency Configurable
• Two Reference Clock Inputs for Dynamic Toggling
• Output Tri-State Control
• Spread Spectrum Compatible
• 3.3V Power Supply
• Industrial Temp. Range: -40°C to +85°C
• 52 Pin TQFP Package
Product Description
The Z9975 is a low cost 3.3V zero delay clock driver for
high speed signal buffering and redistribution.
It provides the designer with the flexibility of selecting
various Output/Input Frequency ratios selected by fsela,
fselb, fselc, fselFB(0:1), and VCO_sel input settings.
The Z9975 integrates PLL technology for Zero delay
propagation from Input to Output. The PLL feedback is
externally available for propagation delay tuning and
divide ratio alternatives as per table 1.
The Z9975 has three banks of outputs with independent
divider stages. These dividers allow the banks to have
different frequencies as per table 2.
TCLK0 and TCLK1 one are selectable input reference
clocks and may be toggled dynamically during operation
to provide modulation and phase shifting designs.
This device includes a Master Reset signal that disables
the outputs into Tristate (Hi-Z) mode, and reset all
internal digital circuitry (excluding the PLL).
An Output Enable, OE, input pin is available for shutting
Qa(0:4), Qb(0:4), and Qc(0:3) outputs in a low state. All
outputs are held low with input clock turned off.
Z9975
3.3V, 150MHz, Multi-Output Zero Delay Buffer
Feedback Ratio Selection Table
Inputs
VCO_Sel1 VCO_Sel0 fselFB0 fselFB1
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
Table 1
Outputs
QFB
VCO/8
VCO/12
VCO/16
VCO/24
VCO/16
VCO/24
VCO/32
VCO/48
VCO/4
VCO/6
VCO/8
VCO/12
VCO/8
VCO/12
VCO/16
VCO/24
Pin Configuration
VSSA
MR#
OE
fselb
fselc
PLL_EN
fsela
TClk_Sel
TClk0
TClk1
VCO_Sel1
VDDI
VDDA
52 51 50 49 48 47 46 45 44 43 42 41 40
1
39
2
38
3
37
4
36
5
35
6
7
Z9975
34
33
8
32
9
31
10
30
11
29
12
28
13
27
14 15 16 17 18 19 20 21 22 23 24 25 26
VSSb
QB1
VDDb
Qb2
VSSb
Qb3
VDDb
Qb4
FB_IN
VSSFB
QFB
VDDFB
NC
Cypress Semiconductor Corporation
http://www.cypress.com
Document#: 38-07091 Rev. *B
12/26/2002
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