CY27020 Spread Spectrum Clock Generator Spread Spectrum Clock Generator Features Functional Description ■ Supports clock requirements for printers ■ 48-MHz spread spectrum clock output ■ 48-MHz reference clock output The CY27020 clock generator provides a low EMI clock output for printers. It features spread spectrum technology, a modulation technique designed specifically for reducing EMI at the fundamental frequency and its harmonics. ■ Two selectable spread percentages: –1% and –3% For a complete list of related documentation, click here. ■ Integrated loop filter ■ 48-MHz crystal or external clock input ■ 3.3-V supply operation (2.5-V functional) ■ 8-pin small outline integrated circuit (SOIC) package Logic Block Diagram XIN Oscillator REFOUT XOUT PLL SSON# SSSEL CLKOUT SSCG Frequency Table XIN SSON# SSSEL REFOUT CLKOUT 48.00 MHz 0 0 48.00 MHz 48.00 MHz at –1% 48.00 MHz 0 1 48.00 MHz 48.00 MHz at –3% 48.00 MHz 1 0 48.00 MHz 48.00 MHz (No Spread) 48.00 MHz 1 1 48.00 MHz 48.00 MHz (No Spread) Cypress Semiconductor Corporation Document Number: 38-07273 Rev. *G • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600 Revised December 5, 2014 CY27020 Pin Configuration Figure 1. 8-pin SOIC pinout 1 VDD 2 VSS 3 XIN 4 CY27020 CLKOUT 8 SSON# 7 REFOUT 6 SSSEL 5 XOUT Pin Description Type [1] Pin Name I/o Description 1 CLKOUT O 2 VDD PWR 3.3-V power supply 3 VSS PWR Ground 4 XIN I Oscillator buffer input. Connect to an external parallel resonant crystal (nominally 48.00 MHz) or externally generated 48 MHz reference clock. 5 XOUT O Oscillator buffer output. Connect to an external parallel resonant crystal. Do not connect when an externally generated reference clock is applied at XIN. Fixed frequency 48.00 MHz spread spectrum clock output. See Table on page 1 for frequency selections 6 SSSEL I PU 7 REFOUT O – 8 SSON# I PD Spread spectrum percentage select input. See Table on page 1 for details. Buffered output of XIN. Spread spectrum enable input. When asserted LOW, spread spectrum is enabled. Spread Spectrum Clock Generation (SSCG) Figure 2. No Spread vs Down Spread Example Spread spectrum clock generation (SSCG) is a frequency modulation technique used to reduce electromagnetic interference radiation generated by repetitive digital signals, mainly clocks. A clock accumulates electromagnetic energy at its center frequency and its harmonics. Spread spectrum distributes this energy over a small frequency band and decreases the peak value of radiated energy over the spectrum. This technique is achieved by modulating the clock around or below the center of its nominal frequency by a certain percentage (which also determines the energy distribution band). The SSCG function is enabled when SSON# pin is asserted low, resulting in a spread bandwidth that is down spread by either –1% or –3%, selected by SSSEL (see Table on page 1). Note 1. PU = Internal pull-up resistor, PD = Internal pull-down resistor. Document Number: 38-07273 Rev. *G Page 2 of 9 CY27020 Absolute Maximum Conditions Exceeding maximum ratings may shorten the useful life of the device. User guidelines are not tested.[2] Minimum input voltage relative to VSS: ...............VSS – 0.3 V This device contains circuitry to protect the inputs against damage due to high static voltages or electric field; however, care should be taken to avoid application of any voltage higher than the maximum rated voltages to this circuit. For proper operation, the I/O pins should be constrained to the range: VSS < I/O < VDD Maximum input voltage relative to VDD: ............. VDD + 0.3 V Unused inputs must always be tied to an appropriate logic voltage level (either VSS or VDD). Storage temperature: ................................. –65 °C to 150 °C Operating temperature: .................................. 0 °C to 70 °C Maximum electrostatic discharge (ESD) protection: ...... 2 kV Maximum power supply: ............................................... 5.5 V Operating voltage: ..............................................2.5 V–3.6 V DC Electrical Specifications (VDD = 3.3 V ± 10%, TA = 0 °C to 70 °C) [3] Parameter Description VIL Input low voltage VIH Input high voltage VthXIN XIN threshold voltage Conditions SSON#, SSSEL Min Typ Max Unit – – 0.8 V 2.2 – – V 0.3 × VDD 0.5 × VDD 0.7 × VDD V IIL1 Input low current SSON# = VSS –5 0 5 A IIH1 Input high current SSON# = VDD 3 8 20 A IIL2 Input low current SSEL = VSS –36 –16.5 –7.4 A IIH2 Input high current SSEL = VDD –5 0 5 A IDD3.3V Dynamic supply current No output load – 20 25 mA VOL Output low voltage IOL = 4.0 mA – – 0.4 V VOH Output high voltage IOH = –4.0 mA Cin Input capacitance Pins 6 and 8 Cx XIN, XOUT capacitance Pins 4 and 5 PU/PD Pull-up/pull-down resistance SSON#, SSSEL 2.4 – – V – 3 5 pF – 3 5 pF 100 200 400 k Notes 2. Multiple Supplies: The Voltage on any input or I/O pin cannot exceed the power pin during power-up. Power supply sequencing is NOT required. 3. In applications where a crystal is used for the input reference clock, refer to the crystal manufacturer’s specifications for the required crystal load capacitor value. Document Number: 38-07273 Rev. *G Page 3 of 9 CY27020 AC Electrical Specifications (VDD = 3.3 V ± 10%, TA = 0 °C to 70 °C) Parameter IFR tr tf Description Min Typ Max Unit Input frequency range 44 48 52 MHz Rise time [4, 5] – 1 2 ns Fall time Conditions [4, 5] – 1 2 ns – –1 – % SSON# = 0, SSSEL = 1 – –3 – % All output clocks – – 3 ms CL = 15 pF 45 50 55 % REFOUT cycle-to-cycle jitter [4, 6] CL = 15 pF – – 350 ps – 100 250 ps SS% Spread spectrum percentage SSON# = 0, SSSEL = 0 tPU Power-up to stable output[6] tDC Clock duty cycle [4, 6] tCCJ CLKOUT cycle-to-cycle jitter [4, 6] Application Schematic Example Figure 3. Application Schematic Example [7, 8] VDD 0 .1 u F VDD 2 X IN 7 4 CL1 1 48 M H z XOUT C Y27020 REFOUT 33 C LKO U T 33 5 CL2 6 SSSEL 8 3 VSS VSS SSON# VSS Notes 4. Parameters are guaranteed by design and characterization. Not 100% tested in production. All parameters specified with fully loaded outputs. All outputs loaded with 15 pF. 5. Measured between 0.1 x VDD and 0.9 x VDD volts. 6. Triggering is done at 1.5 V. 7. The circuit shows -1.0% spread. Refer to Frequency Table on page 1 for details. 8. Use the crystal manufacturer’s recommended values for CL1 and CL2 load capacitors. Document Number: 38-07273 Rev. *G Page 4 of 9 CY27020 Ordering Information Part Number Package Type Production Flow Pb-free CY27020SXC 8-pin SOIC Commercial, 0 °C to 70 °C CY27020SXCT 8-pin SOIC - Tape and Reel Commercial, 0 °C to 70 °C Ordering Code Definitions CY 27020 S X C X X = blank or T blank = Tube; T = Tape and Reel Temperature Range: C = Commercial = 0 C to +70 C X = Pb-free; X Absent = Leaded Package Type: S = 8-pin SOIC Base Part Number Company ID: CY = Cypress Document Number: 38-07273 Rev. *G Page 5 of 9 CY27020 Package Drawing and Dimension Figure 4. 8-pin SOIC (150 Mils) S0815/SZ815/SW815 Package Outline, 51-85066 51-85066 *F Document Number: 38-07273 Rev. *G Page 6 of 9 CY27020 Acronyms Document Conventions Table 1. Acronyms Used in this Document Acronym Description Units of Measure Table 2. Units of Measure CLKOUT Reference Clock Out EMI Electromagnetic Interference °C ESD Electrostatic Discharge k kilohm PD Power Down MHz megahertz PLL Phase Locked Loop µA microampere PPM Parts Per Million µs microsecond SS Spread Spectrum mA milliampere SSC Spread Spectrum Clock ms millisecond SSCG Spread Spectrum Clock Generation mW milliwatt SSON Spread Spectrum ON ns nanosecond ohm pF picofarad ps picosecond V volt W watt Document Number: 38-07273 Rev. *G Symbol Unit of Measure degree Celsius Page 7 of 9 CY27020 Document History Page Document Title: CY27020, Spread Spectrum Clock Generator Document Number: 38-07273 Rev. ECN No. Submission Date Orig. of Change ** 110661 02/19/02 XHT New data sheet. Description of Change *A 122868 12/21/02 RBI Add power up requirements to maximum rating information *B 279429 See ECN RGL Added Lead-free Devices *C 2759365 09/02/2009 TSAI Updated template. Post to external web. *D 2899304 03/25/2010 CXQ Removed inactive parts from Ordering Information Updated Package Drawing and Dimension. *E 3041840 09/29/2010 CXQ Removed “IC” from end of document title. Fixed various formatting and typographical errors. Change all SSON pin references to SSON#. Added row to Table 1 for explicit select pin functional explanation. Removed references to Cera-lock input. Removed redundant Note 3. *F 4162220 10/16/2013 CINM Updated Package Drawing and Dimension: spec 51-85066 – Changed revision from *D to *F. Updated in new template. Completing Sunset Review. *G 4587350 12/05/2014 Document Number: 38-07273 Rev. *G AJU Added related documentation hyperlink in page 1. Page 8 of 9 CY27020 Sales, Solutions, and Legal Information Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office closest to you, visit us at Cypress Locations. PSoC® Solutions Products Automotive Clocks & Buffers Interface Lighting & Power Control cypress.com/go/automotive cypress.com/go/clocks cypress.com/go/interface cypress.com/go/powerpsoc cypress.com/go/plc Memory cypress.com/go/memory PSoC cypress.com/go/psoc Touch Sensing PSoC 1 | PSoC 3 | PSoC 4 | PSoC 5LP Cypress Developer Community Community | Forums | Blogs | Video | Training Technical Support cypress.com/go/support cypress.com/go/touch USB Controllers Wireless/RF psoc.cypress.com/solutions cypress.com/go/USB cypress.com/go/wireless © Cypress Semiconductor Corporation, 2002-2014. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress product. Nor does it convey or imply any license under patent or other rights. Cypress products are not warranted nor intended to be used for medical, life support, life saving, critical control or safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Any Source Code (software and/or firmware) is owned by Cypress Semiconductor Corporation (Cypress) and is protected by and subject to worldwide patent protection (United States and foreign), United States copyright laws and international treaty provisions. Cypress hereby grants to licensee a personal, non-exclusive, non-transferable license to copy, use, modify, create derivative works of, and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress integrated circuit as specified in the applicable agreement. Any reproduction, modification, translation, compilation, or representation of this Source Code except as specified above is prohibited without the express written permission of Cypress. Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not assume any liability arising out of the application or use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Use may be limited by and subject to the applicable Cypress software license agreement. Document Number: 38-07273 Rev. *G Revised December 5, 2014 All products and company names mentioned in this document may be the trademarks of their respective holders. Page 9 of 9