JAJSE20F August 2016 – November 2019 AM5706 , AM5708
PRODUCTION DATA.
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An external crystal is connected to the device pins. Figure 5-9 describes the crystal implementation.
NOTE
The load capacitors, Cf1 and Cf2 in Figure 5-9, should be chosen such that the below equation is satisfied. CL in the equation is the load specified by the crystal manufacturer. All discrete components used to implement the oscillator circuit should be placed as close as possible to the associated oscillator xi_osc0, xo_osc0, and vssa_osc0 pins.
The crystal must be in the fundamental mode of operation and parallel resonant. Table 5-18 summarizes the required electrical constraints.
NAME | DESCRIPTION | MIN | TYP | MAX | UNIT | ||
---|---|---|---|---|---|---|---|
fp | Parallel resonance crystal frequency | 19.2, 20, 27 | MHz | ||||
Cf1 | Cf1 load capacitance for crystal parallel resonance with Cf1 = Cf2 | 12 | 24 | pF | |||
Cf2 | Cf2 load capacitance for crystal parallel resonance with Cf1 = Cf2 | 12 | 24 | pF | |||
ESR(Cf1,Cf2) (1) | Crystal ESR | 100 | Ω | ||||
CO | Crystal shunt capacitance | ESR = 30 Ω
ESR = 40 Ω |
19.2 MHz, 20 MHz, 27 MHz | 7 | pF | ||
ESR = 50 Ω | 19.2 MHz, 20 MHz | 7 | pF | ||||
27 MHz | 5 | pF | |||||
ESR = 60 Ω | 19.2 MHz, 20 MHz | 7 | pF | ||||
27 MHz | Not Supported | - | |||||
ESR = 80 Ω | 19.2 MHz, 20 MHz | 5 | pF | ||||
27 MHz | Not Supported | - | |||||
ESR = 100 Ω | 19.2 MHz, 20 MHz | 3 | pF | ||||
27 MHz | Not Supported | - | |||||
LM | Crystal motional inductance for fp = 20 MHz | 10.16 | mH | ||||
CM | Crystal motional capacitance | 3.42 | fF | ||||
tj(xiosc0) | Frequency accuracy(1), xi_osc0 | Ethernet and MLB not used | ±200 | ppm | |||
Ethernet RGMII and RMII using derived clock | ±50 | ||||||
Ethernet MII using derived clock | ±100 |
When selecting a crystal, the system design must consider the temperature and aging characteristics of a based on the worst case environment and expected life expectancy of the system.
Table 5-19 details the switching characteristics of the oscillator and the requirements of the input clock.
NAME | DESCRIPTION | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|
fp | Oscillation frequency | 19.2, 20, 27 MHz | MHz | ||
tsX | Start-up time | 4 | ms |