SiTime, Silicon MEMS Oscillators and Clock Generators

SiT2021B: High Frequency, Ruggedized One-output Clock Generator

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The SiT2021B is the most robust and reliable high frequency,  single-chip, one-output clock generator on the market with 0.1 PPB/G vibration sensitivity (G-sensivity), 50kg shock and 70g vibration resistance and 500 million hour MTBF. This device delivers the most uncomprising combination of high frequecny (up to 137 MHz), best stability (±20 PPM) and widest temperature range (-55°C to 125°C). It comes in a 5-pin, small SOT23 pacakge that offers the best board level solder joint reliability and enables low cost, optical-ONLY board level inspection.

For the same device in SMD packages, refer to the SiT8921B oscillator.


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)

SOT23-5(2.9 x 2.8 x 1.2)

Status Production
  • Ruggedized applications for harsh environments
  • Applications in extreme temperature conditions

Features Benefits
  • Unique combination of
    • Up to 137 MHz
    • ±20 PPM
    • -55 °C to 125°C operating temperature
  • Best-in-class stability over extreme temperature range for outdoor applications
  • 0.1 ppb/g low G-sensitivity
  • No degradation of performance in harsh operating environment
  • 70 g shock and 50 kg vibration
  • Indestructable
  • Configurable rise/fall time
  • Optimize EMI to reduce intereference to other subsystems
  • SOT23-5 package
  • Best board level solder joint reliability
  • Easy, low cost optical only board level inspection of solder joints
  • Ultra fast lead time (2 to 4 weeks)
  • Reduce inventory overhead
  • Mitigate shortage risks



Measured Performance Reports on SiT2021B

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


List of Supported Frequencies


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



1.8V LVCMOS IBIS icon SiT2021 1p8v
2.5V LVCMOS IBIS icon SiT2021 2p5v
2.8V LVCMOS IBIS icon SiT2021 2p8v
3.0V LVCMOS IBIS icon SiT2021 3p0v
3.3V LVCMOS IBIS icon SiT2021 3p3v
2.25V - 3.63V LVCMOS IBIS icon SiT2021 xx