ZHCSN40K February 2019 – April 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1
PRODUCTION DATA
Figure 6-23 shows the recommended crystal circuit. All discrete components used to implement the oscillator circuit should be placed as close as possible to the WKUP_OSC0_XI and WKUP_OSC0_XO pins.
Figure 6-23 WKUP_OSC0
Crystal ImplementationThe crystal must be in the fundamental mode of operation and parallel resonant. Table 6-21 summarizes the required electrical constraints.
| PARAMETER | MIN | TYP | MAX | UNIT | |||
|---|---|---|---|---|---|---|---|
| Fxtal | Crystal Parallel Resonance Frequency | 19.2, 20, 24, 25, 26, 27 | MHz | ||||
| Fxtal | Crystal Frequency Stability and Tolerance | Ethernet RGMII and RMII not used | ±100 | ppm | |||
| Ethernet RGMII and RMII using derived clock | ±50 | ||||||
| CL1+PCBXI | Capacitance of CL1 + CPCBXI | 12 | 24 | pF | |||
| CL2+PCBXO | Capacitance of CL2 + CPCBXO | 12 | 24 | pF | |||
| CL | Crystal Load Capacitance | 6 | 12 | pF | |||
| Cshunt | Crystal Circuit Shunt Capacitance | ESRxtal = 30 Ω | 19.2 MHz, 20 MHz, 24 MHz, 25 MHz, 26 MHz, 27 MHz |
7 | pF | ||
| ESRxtal = 40 Ω | 19.2 MHz, 20 MHz, 24 MHz, 25 MHz, 26 MHz, 27 MHz |
5 | pF | ||||
| ESRxtal = 50 Ω | 19.2 MHz, 20 MHz, 24 MHz, 25 MHz, 26 MHz, 27 MHz |
5 | pF | ||||
| ESRxtal = 60 Ω | 19.2 MHz, 20 MHz, 24 MHz | 5 | pF | ||||
| ESRxtal = 80 Ω | 19.2 MHz, 20 MHz | 5 | pF | ||||
| 25 MHz | 3 | pF | |||||
| ESRxtal = 100 Ω | 19.2 MHz, 20 MHz | 3 | pF | ||||
| ESRxtal | Crystal Effective Series Resistance | 100 | Ω | ||||
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 6-22 details the switching characteristics of the oscillator and the requirements of the input clock.
| PARAMETER | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|
| CXI | XI Capacitance | 1.55 | pF | ||
| CXO | XO Capacitance | 1.35 | pF | ||
| CXIXO | XI to XO Mutual Capacitance | 0.1 | pF | ||
| ts | Maximum Start-up Time | 9.5(1) | ms | ||
Figure 6-24 WKUP_OSC0
Start-up Time