SiT9005 Spread-Spectrum Oscillator

The SiTime SiT9005 spread-spectrum oscillator (SSXO) addresses electromagnetic interference (EMI) compliance requirements that often delay product certification and production. Emissions testing occurs late in the design cycle, and failures at that stage trigger troubleshooting, board-level rework, and schedule delays. The SiT9005 mitigates this risk by integrating two configurable EMI reduction techniques: spread-spectrum clocking and rise/fall time control. Together, these techniques reduce emissions by up to 17 dB on the carrier frequency and up to 30 dB on harmonics.

The device supports frequencies from 1 MHz to 141 MHz with six-decimal-place accuracy. Spread-spectrum modulation is configurable in range and profile, with center spread up to ±2.0% and down spread to -4.0%. Engineers can select triangular or Hershey's Kiss profiles to align with system timing requirements. Eight rise/fall time options provide additional spectral control. Cycle-to-cycle jitter of 8.5 ps minimizes impact on system timing budgets during spread modulation.

Field programmability through the SiTime Time Machine II oscillator programmer allows engineers to configure spread parameters and drive strength on the bench, then validate emissions performance in real time. This eliminates the need to order new samples and repeat validation cycles. Zero sample lead-time shortens the design-to-compliance cycle. Frequency stability options of ±20 ppm, ±25 ppm, and ±50 ppm support operating ranges from -20°C to +70°C and -40°C to +85°C. Supply options of 1.8 V and 2.5 V to 3.3 V support a range of system power architectures.

The SiT9005 is available in industry-standard packages of 2.0 mm x 1.6 mm, 2.5 mm x 2.0 mm, and 3.2 mm x 2.5 mm, with larger options available on request. These packages support drop-in replacement without board redesign. The 2.0 mm x 1.6 mm package is an extremely small spread-spectrum oscillator, conserving board space in constrained designs. The device replaces quartz oscillators and eliminates the need for shielding, absorber materials, and other board-level EMI mitigation methods.

The MEMS architecture from SiTime provides advantages over quartz in EMI-sensitive environments. Vibration immunity and the absence of activity dips ensure stable spread modulation under mechanical stress and across the full operating temperature range. Programmability across frequency, spread parameters, drive strength, and package consolidates inventory and reduces qualification effort. In applications where emissions compliance is a gating requirement, the SiT9005 provides a plug-and-play solution that accelerates time to market.