ZHCSIE4A June 2018 – July 2018 TMS320F28035-EP
PRODUCTION DATA.
The on-chip crystal oscillator X1 and X2 pins are 1.8-V level signals and must never have 3.3-V level signals applied to them. If a system 3.3-V external oscillator is to be used as a clock source, it should be connected to the XCLKIN pin only. The X1 pin is not intended to be used as a single-ended clock input, it should be used with X2 and a crystal.
The typical specifications for the external quartz crystal (fundamental mode, parallel resonant) are listed in Table 5-12. Furthermore, ESR range = 30 to 150 Ω.
| FREQUENCY (MHz) | Rd (Ω) | CL1 (pF) | CL2 (pF) |
|---|---|---|---|
| 5 | 2200 | 18 | 18 |
| 10 | 470 | 15 | 15 |
| 15 | 0 | 15 | 15 |
| 20 | 0 | 12 | 12 |
Figure 5-5 Using the On-chip Crystal Oscillator NOTE
Figure 5-6 Using a 3.3-V External Oscillator