PI6C9911 Datasheet, PDF (1/9 Pages) Pericom Semiconductor Corporation – 5V High-Speed Programmable Skew Clock Buffers

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5V High-Speed Programmable Skew
Clock Buffers - SuperClock^®
Product Features
• Four pairs of programmable skew outputs
• User-selectable output functions:
− Selectable skews
− Inverted and noninverted
− Operation at ½ and ¼ input frequency
− Operation at 2X and 4X input frequency
• Low skew <100ps typical same pair, 250ps max.
• Allow REF clock input to have Spread Spectrum
modulation for EMI reduction
• 2X, 4X, ½ and ¼ outputs
• 3-level inputs for skew and output frequency control
• External feedback, internal loop filter
• Low cycle-to-cycle Jitter: <25ps RMS
• Duty cycle of output clock signals: 45% min. 55% max.
• Same pinout as Cypress CY7B9911
• Available in 32-pin PLCC Package (J)
• Output Operation
3.75 to 100 MHz for PI6C9911
3.75 to 125 MHz for PI6C9911E
Description
The PI6C9911 and PI6C9911E are low-skew, low jitter, 5V phase-
lock-loop (PLL) programmable skew clock drivers, for
high-performance computing and networking applications. These
parts offer user-selectable skew-control of 4 output pairs, provid-
ing the timing delays necessary to optimize high-performance
clock-distribution circuits.
Each output can be hardwired to one of nine delay or function
configurations. Delay increments are determined by the input clock
frequency and the configurations selected by the user.
The PI6C9911 and PI6C9911E allow the REF clock input to have
Spread Spectrum modulation for EMI reduction.
Both buffers are pin-compatable with Cypress’s RoboClock
CY7B9911, but with improved AC/DC characteristics.
The PI6C9911 and PI6C9911E also have the same pinout as
Cypress’s CY7B9911and with balanced output drive.
Logic Block Diagram
TEST
FB ^Phase
REF
Freq
Det
Filter
FS
4F0
4F1
3F0
3F1
Three Level
Select Inputs
2F0
2F1
1F0
1F1
Vco and
Time Unit
Generator
SKEW
SELECT
MATRIX
Pin Configuration
4 3 2 1 32 31 30
3F1 5
29 2F0
4F0 6
28 GND
4Q0
4F1 7
27 1F1
4Q1
VCCQ 8
32-Pin
26 1F0
J
3Q0
VCCN 9
25 VCCN
3Q1
4Q1 10
4Q0 11
2Q0
GND 12
24 1Q0
23 1Q1
22 GND
2Q1
GND 13
21 GND
14 15 16 17 18 19 20
1Q0
1Q1
1
PS8451B 03/28/01