Datasheet PI6CG33402C (Diodes) - 21
| Manufacturer | Diodes |
| Description | 3.3V Very-Low Power 4-Output PCIe Clock Generator With On-chip Termination |
| Pages / Page | 24 / 21 — PI6CG33402C. Crystal Circuit Connection. Crystal Oscillator Circuit. … |
| File Format / Size | PDF / 1.7 Mb |
| Document Language | English |
PI6CG33402C. Crystal Circuit Connection. Crystal Oscillator Circuit. Crystal Capacitor Calculation. XTAL_IN. XTAL_OUT
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PI6CG33402C Crystal Circuit Connection
The following diagram shows PI6CG33402C crystal circuit connection with a parallel crystal. For the CL = 8pF crystal, it is suggested to use C1 = 8pF, C2 = 8pF. C1 and C2 can be adjusted to fine tune to the target ppm of crystal oscillator according to different board layouts based on the following formula in the Crystal Capacitor Calculation diagram.
Crystal Oscillator Circuit
XTAL_IN C1 8pF FL2500262Q Crystal�(C =�8pF) L� XTAL_OUT C2 8pF
Crystal Capacitor Calculation XTAL_IN XTAL_OUT CL= crystal spec. loading cap. Cj = chip in/output cap. (3~5pF) Cj Cj Cb = PCB trace/via cap. (2~4pF) Rf Pseudo Rd C1, C2 = load cap. components Cb sine Rd = drive level res. (100Ω) Cb C1 C2 Final choose/trim C1=C2=2 *CL - (Cb +Cj) for the target +/-ppm Example: C1=C2=2*(18pF) – (4pF+5pF)=27pF Recommended Crystal Specification Diodes recommends:
a) FL2500217, SMD 3.2x2.5(4P), 25MHz, CL=8pF, +/-20ppm, https://www.diodes.com/assets/Datasheets/FL.pdf b) FH2500016, SMD 2.5x2.0(4P), 25MHz, CL=8pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/FH.pdf c) FW2500031, SMD 2.0x1.6(4P), 25MHz, CL=8pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/FW.pdf d) US2500003, SMD 1.6x1.2(4P), 25MHz, CL=12pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/US.pdf PI6CG33402C www.diodes.com January 2020 Document Number DS42294 Rev 3-2 21 Diodes Incorporated
PI6CG33402C Crystal Circuit Connection
The following diagram shows PI6CG33402C crystal circuit connection with a parallel crystal. For the CL = 8pF crystal, it is suggested to use C1 = 8pF, C2 = 8pF. C1 and C2 can be adjusted to fine tune to the target ppm of crystal oscillator according to different board layouts based on the following formula in the Crystal Capacitor Calculation diagram.
Crystal Oscillator Circuit
XTAL_IN C1 8pF FL2500262Q Crystal�(C =�8pF) L� XTAL_OUT C2 8pF
Crystal Capacitor Calculation XTAL_IN XTAL_OUT CL= crystal spec. loading cap. Cj = chip in/output cap. (3~5pF) Cj Cj Cb = PCB trace/via cap. (2~4pF) Rf Pseudo Rd C1, C2 = load cap. components Cb sine Rd = drive level res. (100Ω) Cb C1 C2 Final choose/trim C1=C2=2 *CL - (Cb +Cj) for the target +/-ppm Example: C1=C2=2*(18pF) – (4pF+5pF)=27pF Recommended Crystal Specification Diodes recommends:
a) FL2500217, SMD 3.2x2.5(4P), 25MHz, CL=8pF, +/-20ppm, https://www.diodes.com/assets/Datasheets/FL.pdf b) FH2500016, SMD 2.5x2.0(4P), 25MHz, CL=8pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/FH.pdf c) FW2500031, SMD 2.0x1.6(4P), 25MHz, CL=8pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/FW.pdf d) US2500003, SMD 1.6x1.2(4P), 25MHz, CL=12pF, +/-30ppm, https://www.diodes.com/assets/Datasheets/US.pdf PI6CG33402C www.diodes.com January 2020 Document Number DS42294 Rev 3-2 21 Diodes Incorporated
