SAM4CM_14 Datasheet, PDF (1117/1177 Pages) ATMEL Corporation – Atmel | SMART ARM-based Flash MCU

Example: Calculated Track time is lower than actual ADC clock period
 Assuming: f_{CK_ADC} = 1 MHz (t_{CK_ADC} = 1 µs), R_SOURCE = 100Ω and V_DDIN = 3.3V
 The minimum required track time is: t_TRACK = 0.12 x 100 + 500 = 512 ns
 t_TRACK being less than t_{CK_ADC}, TRACKTIM is set to 0. Actual track time is t_{CK_ADC} = 1 µs
 The calculated sampling rate is: f_S = 1 MHz / 24 = 41.7 kHz
 The maximum allowable source resistance is: R_{SOURCE_MAX} = (1000 - 500) / 0.12 = 4.1 kΩ
Example: Calculated Track time is greater than actual ADC clock period
 Assuming: f_{CK_ADC} = 16 MHz (t_{CK_ADC} = 62.5ns), R_SOURCE = 600Ω and V_DDIN = 2.8V
 The minimum required track time is: t_TRACK = 0.12 x 600 + 1000 = 1072 ns
 TRACKTIM = floor (1072 / 62.5) = 17. Actual track time is: (17 + 1) x t_{CK_ADC} = 1.125 µs
 The calculated sampling rate is: f_S = 16 MHz / (24 + 17) = 390.2 kHz
 The maximum allowable source resistance is : R_{SOURCE_MAX} = (1125 - 1000) / 0.12 = 1.04 kΩ
SAM4CM Series [DATASHEET]
Atmel-11203C-ATARM-SAM4CM32-SAM4CM16-SAM4CM8-Datasheet_06-Oct-14
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