Instruction/ maintenance manual of the product CY7B991 Cypress
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CY7B991 CY7B992 Programmable Skew Clock Buf fer Cypress Semiconductor Corpora tion • 198 Champion Court • San Jose , CA 95134-1709 • 408-943-2600 Document Number: 38-07138 Rev . *B Revised June 22, 2007 Features ■ All output pair skew <100 ps typical (250 maximum) ■ 3.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 2 of 19 Pin Configuration Pin Definitions Signal Name IO Description REF I Reference frequency input. Th is input supplies the freque ncy and timing against which all functional variations are measured.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 3 of 19 Block Diagram Description Phase Frequency Detect or an d Filter The Phase Frequency Detector and Filter blocks accept inputs from the r.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 4 of 19 T est Mode The TEST input is a three level inp ut. In normal system operation, this pin is connecte d to ground, enabling the CY7B991 or CY7B992 to operate as expl ained in “Skew Select Matrix” on page 3 .
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 5 of 19 Maximum Ratin gs Operating outside these boundaries affects the performance and life of the device. These user guidel ines are not tested. S torage T emperature .... ... ... ... ... ....
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 6 of 19 Electrical Characteristics Over the Operating Range [6] CY7B991 CY7B992 Parameter Description T est Conditions Min Max Min Max Unit V OH Output HIGH V oltage V CC = Min I OH = – 16 mA 2.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 7 of 19 Cap acita nce CMOS output buffer current and power d issipa tion specified at 50 MHz re ference frequency . Parameter Description T est Cond ition s Max Unit C IN Input Capacitance T A = 25 ° C, f = 1 MHz, V CC = 5.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 8 of 19 Switching Characteristics Over the Operating Range [2, 13] CY7B991–2 [14] CY7B992–2 [14] Parameter Description Min Ty p Max Min Ty .
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 9 of 19 Switching Characteristics Over the Operating Range [2, 13] (continued) CY7B991–5 CY7B992–5 Parameter Description Min Ty p Max Min T.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 10 of 19 Switching Characteristics Over the Operating Range [2, 13] (continued) CY7B991–7 CY7B992–7 Parameter Descr iption Min Ty p Ma x Mi.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 1 1 of 19 AC Timing Diagrams t ODCV t ODCV t REF REF FB Q OTHER Q INVERTED Q REF DIVIDED BY 2 REF DIVIDED BY 4 t RPWH t RPWL t PD t SKEWPR, t S.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 12 of 19 Operational M ode Descriptions Figure 2 shows the PSCB configure d as a zero skew clock buffer . In this mode the 7B991/992 is us ed as th e basis for a low-skew clock distribution tree.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 13 of 19 the FB and REF inputs and ali gns their rising edges to ensure that all outputs have precise phase alignment. Clock skews are advanced by ±6 time units (tU) when using an output selected for zero skew as the feedback.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 14 of 19 range since the highest frequency output i s running at 20 MHz. Figure 7 shows some of the fu nctions that are se lectable on the 3Qx and 4Qx outputs. These include inverted outputs and outputs that offer divide-by-2 and d ivide-by-4 timing.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 15 of 19 Figure 8 shows the CY7B991 and 992 connected in se ries to construct a zero skew clock distribution tree between boards.
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 16 of 19 Ordering Information Accuracy (p s) Ordering Co de Package T ype Operating Range 250 CY7B991–2JC 32-Pb Pl astic Leaded Chip Carrier .
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 17 of 19 Milit ary Specifications Group A Subgroup T esting DC Characteristics Parameter Subgroups V OH 1, 2, 3 V OL 1, 2, 3 V IH 1, 2, 3 V IL .
CY7B991 CY7B992 Document Number: 38-0713 8 Rev . *B Page 18 of 19 Figure 10. 32-Pin Rectang ular Leadless Chip Carrier Package Diagrams (continued) MIL-STD-1835 C-12 51-85002-*B [+] Feedback.
Document Number: 38-07138 Rev . *B Revise d June 22, 2007 Page 19 of 19 PSoC Designer™, Programmable System-on-Chip ™, an d PS oC Exp re ss™ are tra demarks a nd PSo C® is a registe red t rade mark of Cypress S emi con ductor Corp.
An important point after buying a device Cypress CY7B991 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Cypress CY7B991 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Cypress CY7B991 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Cypress CY7B991 you will learn all the available features of the product, as well as information on its operation. The information that you get Cypress CY7B991 will certainly help you make a decision on the purchase.
If you already are a holder of Cypress CY7B991, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Cypress CY7B991.
However, one of the most important roles played by the user manual is to help in solving problems with Cypress CY7B991. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Cypress CY7B991 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
