When using a quartz crystal, it may be necessary to include a damping resistor (RD) in the crystal circuit to prevent overdriving the crystal (drive level can be found in the crystal data sheet). In higher-frequency applications (10 MHz or greater), RD is generally not required. If a damping resistor is required, RD should be as small as possible because the size of the resistance affects start-up time (smaller RD = faster start-up time). TI recommends that the crystal manufacturer characterize the crystal with the application board. Table 5-19 lists the crystal oscillator parameters. Table 5-20 lists the crystal equivalent series resistance (ESR) requirements. Table 5-21 lists the crystal oscillator electrical characteristics.