3EQHM57 Group R Low EMI Oscillators 7 x 5 x 1.8mm SMD Spread Spectrum Clock Ocillator Page 1 of 2 Provides up to 15dB reduction in system EMI Drop-in replacement for standard clocks Choice of modulation rate and spread Miniature package: 7.0 mm x 5.0 mm x 1.8mm In electrical systems the principal cause of electro- magnetic interference (EMI) is the system clock DESCRIPTION oscillator. Traditional methods of patching-up systems EQHM57 series low EMI oscillators can reduce system EMI by 15dB. with too high a level of EMI is to use ferrite beads, The oscillators are a drop-in replacement for standard oscillators. filters, ground planes, metal shielding and similar costly EMI reduction is achieved by the use of Spread Spectrum Technology methods, However, the most efficient and economic whereby the mode energy is spread over a wider bandwidth. The method to reduce EMI is to reduce it at source: replace modulation carrier frequency, operating in the kHz region, makes the process transparent to the oscillator frequency. There is a choice of the system clock ocillator with a low EMI clock oscillator. modulation rates and spread to suit application requirements. Compared with conventional clock oscillators, Spread Spectrum (Dithered) Oscillators can reduce EMI by as much as 15dB. The part is a drop-in replacement for a SPREAD SPECTRUM TECHNOLOGY standard clock oscillator hence there is no requirement Unlike a conventional clock oscillator, in a Spread Spectrum Clock to re-design existing PCBs. Oscillator the mode energy is spread over a wider bandwidth. This is achieved by the frequency modulation technique. The controlled modulation process may be applied to the down side of the nominal frequency (known as DOWN SPREAD,) or spread equally either side APPLICATIONS of nominal (CENTRE SPREAD). Down Spread is preferred if over- Printers, Multiple Function Printers (MPCs) clocking would cause a problem to the system. Digital Copiers PDAs Networking: LAN/WAN Routers Storage Systems (CD-ROM, VCD, DVD, HDD) Scanners Modems Projectors Embedded Systems Musical Instruments Automotive: GPS car navigation systems LCD PC Monitors LSD TVs ADSL PCMCIA Still Digital Cameras (SDCs) MODULATION TYPES - EXAMPLES Output amplitude (dB) vs. frequency span (MHz) EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info euroquartz.co.uk www.euroquartz.co.uk3EQHM57 Group R Low EMI Oscillators 7 x 5 x 1.8mm SMD Spread Spectrum Clock Ocillator Page 2 of 2 SPECIFICATION Model No: 3EQHM57 (Group R) OUTLINE & DIMENSIONS Frequency Range: 3.5MHz to 165.0MHz Spread Types: See table below EMI Reduction*: -7dBc min. 100MHz at C0.25** -9dBc min. 100MHz at C0.5** -15dBc min. 100MHz at C1.5** With reference to dB level at no modulation. Modulation Carrier Frequency: 6.9kHz min, 55.5kHz max. Frequency dependent Call for details Output Logic: CMOS Input Voltage: Vdd = +3.3VDC 5% Frequency Stability*** Commercial (0~70C): 25ppm (Spec. code = A) 50ppm (Spec. code = B) 100ppm (Spec. code = C) Industrial (-40~+85C): 25ppm (Spec. code = D) 50ppm (Spec. code = E) 100ppm (Spec. code = F) Output Voltage HIGH 1: 2.0V min., 3.2V typ. (90%Vdd) Output Voltage LOW 0: 0.8V max., 0.2V typ. (10%Vdd) Rise/fall Times: 4ns max, (frequency dependant) Load: 15pF Start-up Time: 2ms typical, 5ms max. Storage Temperature: -65 to +150C Current Consumption: 10 ~ 50MHz: 10mA typical 50 ~ 125MHz: 18mA typical Duty Cycle: 50%5% (CL=15pF, 50%Vdd) Cyle to Cycle Jitter: 250ps typ. 300ps max. ENVIRONMENTAL SPECIFICATION Output Impedance: 40 Ohms typical Static Discharge Voltage: >2000V (per MIL STD 833) RoHS Compliance: RoHS compliant and Pb (lead) free Ageing: 5ppm /year max at Ta=25C Storage Temperature Range: -55 to +125C Packaging: EIA 16mm tape and reel, 1k per. Humidity: 85% RH, 85C for 48 hours Pad 1 Option: Output Enable/Disable. Output is -8 3 Hermetic Seal: Leak Rate 2x10 ATM-cm /s max. high impedance when taken low Solderability: MIL-STD-2002F method 208E Output enable time 100ms max. Reflow: 260 for 10 seconds Notes: Vibration: MIL-STD-202F method 204, * EMI reduction is applied to the entire frequency spectrum 35g 50Hz to 2000Hz ** dBc: with respect to no modulation. Frequency and total % Shock: MIL-STD-202F method 213B, test spread dependant. condition: E, 1000g sine wave *** Frequency Stability parameter excludes modulation. AVAILABILITY OF SPREAD TYPES AND MODULATION RATES SPREAD TYPES and % MODULATION PART NUMBER CONFIGURATION DOWN SPREAD T for Tristate Group R D1.0 -1% Series designation D3.0 -3% CENTRE SPREAD 3EQHM57-BT-32.768R-C0.5 C0.5 0.5% Frequency (MHz) C1.5 1.5% Frequency Stability Code A to F. See specification above EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info euroquartz.co.uk www.euroquartz.co.uk