SPRUJF8 May 2026 TMS320F28P551SG
The base ADC clock is provided directly by the system clock. SYSCLK is used to generate the ADC acquisition window. The register ADCCTL2 has a PRESCALE field that determines the ADCCLK. ADCCLK is used to clock the converter, and is only active during the conversion phase. At all other times, including during the sample-and-hold window, the ADCCLK signal is gated off.
The ADC core requires approximately 10.5 ADCCLK cycles to process a voltage into a conversion result. The user must determine the required duration of the acquisition window, see Choosing an Acquisition Window Duration.