ZHCABK1A February 2022 – March 2024 ADS1119 , ADS1120 , ADS1120-Q1 , ADS112C04 , ADS112U04 , ADS1130 , ADS1131 , ADS114S06 , ADS114S06B , ADS114S08 , ADS114S08B , ADS1158 , ADS1219 , ADS1220 , ADS122C04 , ADS122U04 , ADS1230 , ADS1231 , ADS1232 , ADS1234 , ADS1235 , ADS1235-Q1 , ADS124S06 , ADS124S08 , ADS1250 , ADS1251 , ADS1252 , ADS1253 , ADS1254 , ADS1255 , ADS1256 , ADS1257 , ADS1258 , ADS1258-EP , ADS1259 , ADS1259-Q1 , ADS125H01 , ADS125H02 , ADS1260 , ADS1260-Q1 , ADS1261 , ADS1261-Q1 , ADS1262 , ADS1263 , ADS127L01 , ADS130E08 , ADS131A02 , ADS131A04 , ADS131E04 , ADS131E06 , ADS131E08 , ADS131E08S , ADS131M02 , ADS131M03 , ADS131M04 , ADS131M06 , ADS131M08
如前一節(jié)所述，當(dāng) OSR 提高（ODR 降低）時(shí)，Δ-Σ ADC 數(shù)字濾波器會(huì)獲取更長(zhǎng)時(shí)間段的數(shù)據(jù)，從而直接影響系統(tǒng)噪聲性能。這可以在較低的數(shù)據(jù)速率下實(shí)現(xiàn)較低的測(cè)量噪聲。表 5-1 顯示了 ADS1235 噪聲傾向于隨著 ODR 降低而降低。
還可以使用外部過(guò)采樣方法進(jìn)一步降低噪聲。如果微控制器采集 N 個(gè) ADC 數(shù)據(jù)點(diǎn)的數(shù)據(jù)并求平均值，噪聲可按系數(shù) √N 降低。例如，ADS1235 noise 在增益 = 128V/V、使用 FIR 濾波器且 ODR = 20SPS 的條件下，表 5-1 中給出的 ADS1235 噪聲為 0.029μVRMS 和 0.16μVPP。對(duì) 20 個(gè)數(shù)據(jù)點(diǎn)求平均可使噪聲按照系數(shù) √20 = 4.47 分別降低至 0.0065μVRMS 和 0.036μVPP。但是，應(yīng)用額外的求平均會(huì)延長(zhǎng)延遲時(shí)間。