High frequency, -55°C to 125°C, Active Resonator Drop-In Replacement for 4-pin SMD XTAL


The XCalibur™ SiT1421 active resonator is a drop-in replacement for 4-pin SMD quartz crystal resonators with wide temperature operation. Compared to traditional crystal resonators, XCalibur resonators have better reliability and better immunity to shock, vibration, and EMI. This resonator provides industry-best 0.1 ppb/g vibration sensitivity, 10,000 g shock and 70 g vibration resistance. As an active MEMS device, the SiT1421 eliminates issues related to crystal resonators, such as cold startup under all conditions, crystal motional series resistance (ESR) compensation, negative resistance testing, and the need for tuning capacitors. One XCalibur active resonator can drive up to two clock inputs. This device also features a wide frequency range, excellent stability, and short lead times for a range of high temperature applications.

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Five industry standard footprints as small as 2016 for all frequencies, voltages, and stabilities
"Specs" "Value"
Frequency 119 to 137 MHz
Frequency Stability (ppm) ±15 at 25°C, ±20 all-inclusive, ±25 all-inclusive, ±30 all-inclusive, ±50 all-inclusive
Operating Temperature Range (°C) -55 to +125, -40 to +150 (Contact SiTime)
Package Type (mm²) 2.5x2.0, 3.2x2.5
External Load Capacitance (pF) 4,700 (4.7 nF) ±10%
Output Type LVCMOS
FlexEdgeTM Rise/Fall Time Yes, programmable drive strength
Voltage Supply (V) 1.8, 2.5 to 3.3
Features Field programmable, Guaranteed startup under all conditions, No tuning cap required, No motional series resistance (ESR), No negative resistance testing
Availability Production

Configurable feature sets

  • Any frequency between 119 and 137 MHz with 6 decimal places of accuracy
  • Stability as low as ±20 ppm
  • Wide temperature operation from -55 to +125°C
  • 1.8 V or 2.5 V to 3.3 V supply voltage
  • Customize specification for optimal system performance
  • Use same base device for many designs, reducing qualification needs

Industry-standard 2520 and 3225 packages for all frequencies, voltages and stabilities

  • 100% drop-in replacement of quartz crystal resonators

0.1 ppb/g low g-sensitivity

  • No performance degradation in harsh environments

10,000 g shock and 70 g vibration

  • Virtually indestructible

FlexEdge™ rise/fall time

  • Optimize EMI to reduce interference to other systems

Ultra-fast lead time (4 to 6 weeks)

  • Reduce inventory overhead
  • Mitigate shortage risks


  • Oil Exploration Drilling
  • Power Amplifiers
  • Geothermal Energy Equipment
  • Industrial Motors
  • Pressure Meters
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