Precaution for use the crystal unit with low CL


1. Note
A crystal unit with low CL is very sensitive to load capacitance variations of the oscillation circuit, so the environment the crystal is operated in. (*1)
Consequently, the tolerance of the oscillation frequency in the actual circuit will exceed the tolerance defined in the crystal specification significantly.
1* Pulling sensitivity [ppm/pF]

Please refer to the below page for the detail.
http://www5.epsondevice.com/cn/information/technical_info/crystal/circuit.html#2

2.Products

    1)For STMicroelectronics
  • Target MCU: STM32F401
  • Epson 32kHz crystal unit
Name CL
[pF]
Part number Pulling Sensitivity *[ppm/pF] Deviation max*
[sec/pF]
FC-135R 6.0 X1A0001410006 34 88
FC-12M 5.0 X1A0000610018 81 210
FC1610AN
5.0 TBD TBD TBD

* : absolute value

    2)For NXP Semiconductors
  • Target Real Time Clock: PCF85263
  • Epson 32kHz crystal unit
Name CL
[pF]
Part number Pulling Sensitivity *[ppm/pF] Deviation max*
[sec/pF]
FC-135R 6.0 X1A0001410006 34 88
FC-135 6.0 Q13FC13500018 35 91
MC-146 6.0 Q13MC14620006 47 122
  • Target MCU: LPC54xxx
  • Epson 32kHz crystal unit
Name CL
[pF]
Part number Pulling Sensitivity *[ppm/pF] Deviation max*
[sec/pF]
FC-135R 6.0 X1A0001410006 34 88

* : absolute value

    3)For Texas Instruments
  • Target MCU: MSP430FR5969
  • Epson 32kHz crystal unit
Name CL
[pF]
Part number Pulling Sensitivity *[ppm/pF] Deviation max*
[sec/pF]
MC-146L 3.7 X1A0001520001 47 122

* : absolute value

    4)For Renesas Electronics
  • Target MCU: RX200、RX600、RX700 Series
  • Epson 32kHz crystal unit
Name CL
[pF]
Part number Pulling Sensitivity *[ppm/pF] Deviation max*
[sec/pF]
MC-146L 3.7 X1A0001520001 47 122

* : absolute value

3.Notes

CL=5.0[pF] and 6.0[pF] are not our standard specification so if you will use them please contact our sales person. We would like to check about specification in our company.

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