Low EMI clock oscillators. Reduce EMI by 12 dB. Package size is 5x7x1.8 mm. Drop-in replacement for existing oscillators. No PCB re-spinning.

Mercury provides a clock oscillator drop-in replacement solution for those products that fail at EMI/EMC compliance testing, strictly imposed by FCC. Traditional ways to deal with such problems include adding ferrite beads, metal shielding, EMI filters, ground plane, etc. However, the principle source of the radiated peak energy is from the system clock signals. Therefore, replacing the conventional clock oscillators with the low EMI type is the most economic and efficient way. The advantages are reduced time-to-market and no board re-spinning.

(PRWEB) January 17, 2004 --The Company: Mercury has been producing low EMI spread spectrum clock oscillators for three years. Packages include a 9.6x11.4x4.7mm FR4 based SMD leadless package and full & half size 4 pin DIPs. To address the market need for a smaller package size for industries such as still digital cameras, wireless LANs and LCD displays, Mercury is announcing the volume production of its HM57 (5x7x1.8 mm 4 pad ceramic leadless SMD package) spread spectrum clock oscillators. An even smaller package, HM53 (5x3.2x1.0 mm), is also in development.

The Product: The HM57 is available from 10.0 MHz to 160.0 MHz, a CMOS square wave output with a supply voltage of +3.3V, a duty cycle of 50%±5%, and spread types that include a down spread (-0.5%, -1% and -3%) and center spread (±0.25%, ±0.5% and ±1.5%). The typical cycle-to-cycle jitter is ±250 ps. The modulation carrier frequency is in the range of 23 to 48 KHz (frequency dependent). While the typical EMI reduction is 12 dB. Currently, sample lead times are 3 to 4 weeks with volume lead time at 5 to 6 weeks.
      
The Technology: Unlike conventional clocks whose mode energy has a narrow bandwidth and a sharp peak type, the mode energy of a spread spectrum clock is spread over a wider bandwidth, resulting from the frequency modulation technique. The modulation carrier frequency is in the KHz range which makes the modulation process transparent to the oscillator frequency. The controlled modulation process can be on all of one side of the nominal frequency (down spread) or 50% up and 50% down (center spread). The down spread is preferred if over-clocking is a problem to the system.

Related product link: http://www.mercury-crystal.com/clk_hm.htm