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Manual Cypress FS781

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  • Cypress FS781 - page 1

    Low EMI S pectrum S pread Clock FS781/82/84 Cypress Semiconductor Corpora tion • 198 Champion Cou rt • San Jose , CA 95134-1 709 • 408-943-2 600 Document #: 38-07029 Rev . *F Revised January 2, 2005 Features • Spread S pectrum clock generator (SSCG) with 1×, 2× , and 4× outpu t s • 6- to 82-MHz operating freq u ency range • Modulates ...

  • Cypress FS781 - page 2

    FS781/82/84 Document #: 38-07029 Rev . *F Page 2 of 12 Output Frequency Selection Loop Filter Selection Chart The following table provides a list of recommended l oop filter values for the FS781/82/84. T he FS78X is divided into four ranges and operated at both 3. 3V and 5.5 VDC. The loop filter at the right is representative of the loop filter com ...

  • Cypress FS781 - page 3

    FS781/82/84 Document #: 38-07029 Rev . *F Page 3 of 12 T ab le 2. FS781/82/8 4 Recommended Loop Filter V alu es C7 (pF) @ +3.3 VDC ±5% (R6 = 3.3K) [1, 2, 3, 4] Input MHz S1 S0 BW = 1.0% [3] BW = 1.5% [3] BW = 2.0% [3] BW = 2. 5% [3] BW = 3. 0% [3] BW = 3.5% [3] BW = 4.0% [3] 6 0 0 10,000/1000 1550 910 780 700 6 40 560 8 0 0 10,000/330 990 820 640 ...

  • Cypress FS781 - page 4

    FS781/82/84 Document #: 38-07029 Rev . *F Page 4 of 12 T ab le 3. FS781/82/8 4 Recommended Loop Filter V alu es C7 (pF) @ +5.0 VDC ±5% (R6 = 3.3K) [1, 2, 3, 4] Input MHz S1 S0 BW = 1.0% [3] BW = 1.5% [3] BW = 2.0% [3] BW = 2.5% [3 ] BW = 3.0% [3] BW = 3.5% [3] BW = 4.0% [3] 6 0 0 1 140 1030 930 8 30 710 610 510 8 0 0 1 170 970 740 570 4 60 400 280 ...

  • Cypress FS781 - page 5

    FS781/82/84 Document #: 38-07029 Rev . *F Page 5 of 12 SSCG Modulation Profile The digital control inputs S0 and S1 determine th e modulation frequency of FS781/2/4 products. The input freque ncy is divided by a fixed number, depending on the operating range that is selected. The modulation frequency of the FS78x can be determined from Ta b l e 4 . ...

  • Cypress FS781 - page 6

    FS781/82/84 Document #: 38-07029 Rev . *F Page 6 of 12 From the above parameters, the output clock at FSOUT will be sweeping symmetrically around a center frequency of 20 MHz. The minimum and maximu m extremes of this clock will be +200 kHz and –200 kHz. So we have a clock that is sweeping from 19.8 MHz to 20.2 MHz and back again. If we were to l ...

  • Cypress FS781 - page 7

    FS781/82/84 Document #: 38-07029 Rev . *F Page 7 of 12 ** ** Occasionally , C8 is us ed to create a s econd pole fo r this l oop filter. Refer to Loop Filter Selec tion table. Mount l oop filter c ompo nents as close to LF pin as possible . . Crystal is 2 0 MHz is 1st Orde r with 18 pF l oad capa citance. If Crystal l oad capacita nce is differe nt ...

  • Cypress FS781 - page 8

    FS781/82/84 Document #: 38-07029 Rev . *F Page 8 of 12 Absolute Maximum Ratings [6] This device contains circuitry to protect the input against damage due to high static voltages or electric fields; however , precautions should b e taken to avoid application of any voltage higher than the absolute maxi mum rated voltages to this circuit. For proper ...

  • Cypress FS781 - page 9

    FS781/82/84 Document #: 38-07029 Rev . *F Page 9 of 12 CCJ FSOUT , Cycle-to-Cycle Jitter , 48 MHz @ 3.30 VDC (Pin 6) – 320 370 ps CCJ FSOUT , Cycle-to-Cycle Jitter , 48 MHz @ 5.0 VDC (Pin 6) – 310 360 ps CCJ FSOUT , Cycle-to-Cycle Jitter , 72 MHz @ 3.30 VDC (Pin 6) – 270 325 ps CCJ FSOUT , Cycle-to-Cycle Jitter , 72 MHz @ 5.0 VDC (Pin 6) – ...

  • Cypress FS781 - page 10

    FS781/82/84 Document #: 38-07029 Rev . *F Page 10 of 12 Marking Example Package Drawing and Dimensions Cypress FS781BS Date Code, Lot # Cypress FS781BT Date Code, Lot # FS781 B S Cypress Device Driver Revision Package S = SOIC T = TSSOP SEATING PLANE P I N1I D 0.230[5.842] 0.244[6.197] 0.157[3.987] 0.150[3.810] 0.189[4.800] 0.196[4.978] 0.050[1.270 ...

  • Cypress FS781 - page 11

    FS781/82/84 Document #: 38-07029 Rev . *F Page 1 1 of 12 © Cypress Semi con duct or C orpo ra ti on , 20 05 . The i nfo r mat ion con t ained herein is subject to ch an ge wi t hou t notice. Cypress Semic onductor Corporation assu mes no responsib ility f or the u se of any circuitr y other than circ uitry embodied in a Cypress pr oduct. Nor does ...

  • Cypress FS781 - page 12

    FS781/82/84 Document #: 38-07029 Rev . *F Page 12 of 12 Document History Page Document Title: FS781/82/84 Low EMI Spectrum Spread Clock Document Number: 38 -0702 9 REV . ECN NO. Issue Date Orig. of Change Description of Cha ng e ** 106948 06/07/01 IKA Convert from IMI to Cypress *A 1 1 1654 02/27/02 I KL Add new marking suffix for SOIC packages. Co ...

Manufacturer Cypress Category Clock

Documents that we receive from a manufacturer of a Cypress FS781 can be divided into several groups. They are, among others:
- Cypress technical drawings
- FS781 manuals
- Cypress product data sheets
- information booklets
- or energy labels Cypress FS781
All of them are important, but the most important information from the point of view of use of the device are in the user manual Cypress FS781.

A group of documents referred to as user manuals is also divided into more specific types, such as: Installation manuals Cypress FS781, service manual, brief instructions and user manuals Cypress FS781. Depending on your needs, you should look for the document you need. In our website you can view the most popular manual of the product Cypress FS781.

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A complete manual for the device Cypress FS781, how should it look like?
A manual, also referred to as a user manual, or simply "instructions" is a technical document designed to assist in the use Cypress FS781 by users. Manuals are usually written by a technical writer, but in a language understandable to all users of Cypress FS781.

A complete Cypress manual, should contain several basic components. Some of them are less important, such as: cover / title page or copyright page. However, the remaining part should provide us with information that is important from the point of view of the user.

1. Preface and tips on how to use the manual Cypress FS781 - At the beginning of each manual we should find clues about how to use the guidelines. It should include information about the location of the Contents of the Cypress FS781, FAQ or common problems, i.e. places that are most often searched by users in each manual
2. Contents - index of all tips concerning the Cypress FS781, that we can find in the current document
3. Tips how to use the basic functions of the device Cypress FS781 - which should help us in our first steps of using Cypress FS781
4. Troubleshooting - systematic sequence of activities that will help us diagnose and subsequently solve the most important problems with Cypress FS781
5. FAQ - Frequently Asked Questions
6. Contact detailsInformation about where to look for contact to the manufacturer/service of Cypress FS781 in a specific country, if it was not possible to solve the problem on our own.

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