EQHM8 Group ‘R’ Low EMI Oscillators 8 pin Dual-in-Line 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: 5.0 mm x 3.2 mm x 1.2mm In electrical systems the principal cause of electromagnetic interference (EMI) is the system clock oscillator. Traditional methods of 'patching-up' systems with too high a level of EMI is to use ferrite beads, filters, ground planes, metal shielding and similar costly methods, However, the most efficient and economic method to reduce EMI is to reduce it at source: replace the system clock ocillator with a low EMI clock oscillator. 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 standard clock oscillator hence there is no requirement to re-design existing PCBs. APPLICATIONS Printers, Multiple Function Printers (MPCs) 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) DESCRIPTION EQHM8 series low EMI oscillators can reduce system EMI by 15dB. The oscillators are a ‘drop-in’ replacement for standard oscillators. EMI reduction is achieved by the use of Spread Spectrum Technology whereby the mode energy is spread over a wider bandwidth. The modulation carrier frequency, operating in the kHz region, makes the process transparent to the oscillator frequency. There is a choice of modulation rates and spread to suit application requirements. SPREAD SPECTRUM TECHNOLOGY Unlike a conventional clock oscillator, in a Spread Spectrum Clock 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 of nominal (CENTRE SPREAD). Down Spread is preferred if overclocking would cause a problem to the system. 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 [email protected] www.euroquartz.co.uk EQHM8 Group ‘R’ Low EMI Oscillators 8 pin Dual-in-Line Spread Spectrum Clock Ocillator Page 2 of 2 SPECIFICATION Model No: Frequency Range: Spread Types: EMI Reduction*: Modulation Carrier Frequency: Output Logic: Input Voltage: Frequency Stability*** Commercial (0~70°C): OUTLINE & DIMENSIONS 3EQHM14 (Group ‘R’) 3.5MHz to 165.0MHz See table below -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. 6.9kHz min, 55.5kHz max. Frequency dependent Call for details CMOS Vdd = +3.3VDC ±5% ±25ppm (Spec. code = ‘A’) ±50ppm (Spec. code = ‘B’) ±100ppm (Spec. code = ‘C’) Industrial (-40~+85°C): Output Voltage HIGH ‘1’: Output Voltage LOW ‘0’: Rise/fall Times: Load: Start-up Time: Storage Temperature: Current Consumption: 10 ~ 50MHz: 50 ~ 125MHz: Duty Cycle: Cycle to Cycle Jitter: Output Impedance: Static Discharge Voltage: Ageing: Packaging: Pad 1 Option: ±25ppm (Spec. code = ‘D’) ±50ppm (Spec. code = ‘E’) ±100ppm (Spec. code = ‘F’) 2.0V min., 3.2V typ. (90%Vdd) 0.8V max., 0.2V typ. (10%Vdd) 4ns max, (frequency dependant) 15pF 2ms typical, 5ms max. -65° to +150°C 10mA typical 18mA typical 50%±5% (CL=15pF, 50%Vdd) ±250ps typ. ±300ps max. 40 Ohms typical >2000V (per MIL STD 833) ±5ppm /year max at Ta=25°C EIA 16mm tape and reel, 1k per. Output Enable/Disable. Output is high impedance when taken low Output enable time 100ms max. Notes: * EMI reduction is applied to the entire frequency spectrum ** dBc: with respect to no modulation. Frequency and total % spread dependant. *** Frequency Stability parameter excludes modulation. PART NUMBER CONFIGURATION AVAILABILITY OF SPREAD TYPES AND MODULATION RATES ‘T’ for Tristate option; Blank if Tristate not required Group ‘R’ SPREAD TYPES and % MODULATION 3EQHM8-BT-32.768R-C0.5 3EQHM18 for SMD version Frequency (MHz) DOWN SPREAD D1.0 -1% D3.0 -3% CENTRE SPREAD Frequency Stability Code ‘A’ to ‘F’. See specification above C0.5 ±0.5% C1.5 ±1.5% EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 [email protected] www.euroquartz.co.uk