SiTime, Silicon MEMS Oscillators and Clock Generators

SiT8921B: High Frequency, Ruggedized Oscillator for Harsh Environments

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The SiT8921B is the most robust and reliable high frequency oscillator on the market with 0.1 PPB/G vibration sensitivity (G-sensivity), 50kg shock and 70g vibration resistance and 500 million hour MTBF. In addition, this device delivers a perfect combination of high frequency (up to 137 MHz), best stability (±20 PPM), widest temperature (-55 to 125°C ) and smallest package (2.0 x 1.6 mm) that are not  available from quartz.

For the same device in a SOT23-5 package, refer to the SiT2021B clock generator.


Freq. Range (MHz)
119.342001 to 120.238999
121.243001 to 121.600999
120.262001 to 121.169999
123.948001 to 137.000000
Freq. Stability (PPM) ±20, ±25, ±30, ±50
Temp Range (°C) -55 to +125
Vibration Sensitivity
0.1 ppb/g (G-sensitivity)
Configurable Rise/Fall Time 0.25 to 1.5 ns (Output load and voltage dependent)
Supply Voltage (V) 1.8, 2.5 to 3.3
Package LxWxH (mm) 2.0x1.6x0.75, 2.5x2.0x0.75, 3.2x2.5x0.75, 5.0x3.2x0.75, 7.0x5.0x0.9
Status Production
  • Ruggedized applications for harsh environments
  • Applications in extreme temperature conditions

Features Benefits
  • Unique combination of
    • high frequency (up to 137 MHz)
    • ±20 PPM
    • widest temperature range (-55 to 125 °C)
    • smallest package (2.0 x 1.6 mmxmm)
  • Best-in-class stability and temp range for space constrained environments
  • 0.1 ppb/g low G-sensitivity
  • No performance degradation in harsh environment
  • 50 kg shock and 70 g vibration
  • Indestructable
  • Configurable rise/fall time
  • Optimize EMI to reduce interferece to other system



Measured Performance Reports on SiT8921B

The following PDF reports contain details of actual measurements on SiTime devices at the frequencies mentioned below and are intended to supplement the datasheet. Measurement conditions and equipment are specified in the individual files. If you desire a more detailed report than the ones provided below, please·contact your local SiTime sales representative·or email·salessupport@sitime.com.


Subject to change without notice


10. Contact SiTime for custom drive strength to drive higher or multiple load, or SoftEdge™ option for EMI reduction.

List of Supported Frequencies


15. Any frequency within the min and max values in the above table are supported with 6 decimal places of accuracy.
16. Please contact SiTime for frequencies that are not listed in the tables above.

Ordering Codes for Supported Tape & Reel Packing Method



1.8V LVCMOS IBIS icon SiT8921 1p8v
2.5V LVCMOS IBIS icon SiT8921 2p5v
2.8V LVCMOS IBIS icon SiT8921 2p8v
3.0V LVCMOS IBIS icon SiT8921 3p0v
3.3V LVCMOS IBIS icon SiT8921 3p3v
2.25V - 3.63V LVCMOS IBIS icon SiT8921 xx