ADS7830: Sampling data error

Matt Qi

Part Number: ADS7830

Hi team,

My customer faced a data error (10%~20% higher) issue when using ADS7830.

2023-12-22 16:23:22,015 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-22 16:23:22,377 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.1389999999999998, range is 1.696~1.9079999999999999
2023-12-22 16:24:49,296 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-22 16:24:50,110 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-22 16:26:16,953 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1389999999999998, range is 1.696~1.9079999999999999
2023-12-22 16:29:47,992 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.387, range is 1.1279999999999999~1.272
2023-12-22 16:29:48,594 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 09:28:36,314 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 09:28:36,821 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.1389999999999998, range is 1.696~1.9079999999999999
2023-12-23 09:30:04,082 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 09:30:04,654 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 09:33:35,642 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 09:33:36,276 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 10:35:03,671 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0310000000000001, range is 1.696~1.9079999999999999
2023-12-23 10:35:04,079 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 10:36:25,804 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 10:36:26,444 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 10:39:42,053 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 10:39:42,576 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 11:32:52,940 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 11:32:53,495 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 11:34:16,064 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 11:34:16,587 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 11:35:38,588 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 11:38:54,857 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 11:38:55,739 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 12:30:01,841 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 12:30:02,452 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 12:31:23,673 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 12:31:24,285 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 12:32:45,965 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 12:34:44,941 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 13:27:29,639 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 13:27:30,438 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 13:30:47,566 - DCDCMON - CRITICAL: P1V0_OCM_PVCCANA_CPU_U39_V(P1V0_OCM_PVCCANA_CPU_U39_V) exceeded upper critical, value is 1.1619999999999999, range is 0.93999999999999995~1.0600000000000001
2023-12-23 13:30:48,385 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.6920000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 13:33:28,798 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 13:33:29,330 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 14:25:36,834 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 14:27:33,086 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 14:27:33,556 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 14:30:14,067 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 14:30:14,356 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 14:31:36,480 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 14:31:37,085 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 15:27:04,930 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 15:29:45,023 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 15:29:45,613 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 15:31:06,707 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 15:31:07,348 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 15:32:28,517 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 16:23:53,851 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 16:23:54,547 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7934000000000001, range is 4.5999999999999996~5.4000000000000004
2023-12-23 16:25:15,967 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 16:27:13,527 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 16:27:14,026 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 16:28:35,199 - DCDCMON - CRITICAL: P1V05_OCM_U39_V(P1V05_OCM_U39_V) exceeded upper critical, value is 1.2310000000000001, range is 0.996~1.1100000000000001
2023-12-23 16:29:55,121 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 16:29:55,971 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 17:27:48,457 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 17:29:10,144 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 17:31:09,849 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 18:21:44,041 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 18:23:05,906 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 18:23:06,403 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 18:24:29,383 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0310000000000001, range is 1.696~1.9079999999999999
2023-12-23 18:24:29,967 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 18:25:49,866 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 18:27:48,439 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 19:26:39,720 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 20:22:17,622 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 20:22:18,007 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 20:23:41,879 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 20:23:42,309 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 20:25:02,828 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 20:26:59,196 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 20:26:59,963 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 21:24:34,866 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 21:25:52,121 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 21:25:52,368 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 21:27:13,725 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 21:27:14,046 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 22:21:34,095 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1000000000000001, range is 1.696~1.9079999999999999
2023-12-23 22:23:29,827 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.73, range is 2.9700000000000002~3.6299999999999999
2023-12-23 22:24:49,011 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 22:24:49,780 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.1389999999999998, range is 1.696~1.9079999999999999
2023-12-23 22:26:10,275 - DCDCMON - CRITICAL: P5V_OCM_AUX_U76_V(P5V_OCM_AUX_U76_V) exceeded upper critical, value is 5.7270900000000005, range is 4.5999999999999996~5.4000000000000004
2023-12-23 22:26:11,050 - DCDCMON - CRITICAL: P1V8_OCM_AUX_NAC_U39_V(P1V8_OCM_AUX_NAC_U39_V) exceeded upper critical, value is 2.1389999999999998, range is 1.696~1.9079999999999999
2023-12-23 23:21:00,841 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0699999999999998, range is 1.696~1.9079999999999999
2023-12-23 23:21:01,612 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.0899999999999999, range is 1.696~1.9079999999999999
2023-12-23 23:22:22,461 - DCDCMON - CRITICAL: P1V8_OCM_U76_V(P1V8_OCM_U76_V) exceeded upper critical, value is 2.0310000000000001, range is 1.696~1.9079999999999999
2023-12-23 23:22:22,973 - DCDCMON - CRITICAL: P1V8_OCM_CPU_U39_V(P1V8_OCM_CPU_U39_V) exceeded upper critical, value is 2.129, range is 1.696~1.9079999999999999
2023-12-23 23:24:21,327 - DCDCMON - CRITICAL: P1V2_OCM_PVDDQ_ABC_CPU_U39_V(P1V2_OCM_PVDDQ_ABC_CPU_U39_V) exceeded upper critical, value is 1.397, range is 1.1279999999999999~1.272
2023-12-23 23:24:21,675 - DCDCMON - CRITICAL: P3V3_OCM_AUX_U76_V(P3V3_OCM_AUX_U76_V) exceeded upper critical, value is 3.7120000000000002, range is 2.9700000000000002~3.6299999999999999
2023-12-23 23:25:42,310 - DCDCMON - CRITICAL: P1V05_OCM_U39_V(P1V05_OCM_U39_V) exceeded upper critical, value is 1.24, range is 0.996~1.1100000000000001

The schematic and log are attached.

The results are compared between the oscilloscope measurement results and I2C data results, and the I2C signal integration is checked.

Actually, the oscilloscope shows no voltage error, and what the I2C data shows is higher.

For example, the oscilloscope shows the 12V, and the ADS7830 reads is 14V.

Are there any potential reasons that can cause this phenomenon?

Thanks for your time and effort.

Best Regards,

Matt.

over 1 year ago

0 Tom Hendrick over 1 year ago

TI__Guru**** 181481 points

Hi Matt,

Can you provide some details on the application? How are you configuring the PD bits? Assuming that you are using the internal reference, adding more capacitance from pin 10 to ground should help. You say the oscope looks line, can you capture the input during the sample interval?

0 Matt Qi over 1 year ago in reply to Tom Hendrick

TI__Expert 4510 points

Hi Tom,

The input during the sample interval (rather long time period) is attached. The input is stable and maintains 12V/3.3V.

I am going to check the PD bits and ask my customer to measure the pin 10.

0 Tom Hendrick over 1 year ago in reply to Matt Qi

TI__Guru**** 181481 points

You need to zoom way in... Do let us know about the PD bits.

0 Matt Qi over 1 year ago in reply to Tom Hendrick

TI__Expert 4510 points

Hi Tom,

The PD bits are 11.

What's more, I asked them to test the REFOUT pin.

And they found this waveform:

I think maybe the internal reference voltage distortion that can cause this problem.

What's the potential cause of this phenomenon?

Best Regards,

Matt.

0 Tom Hendrick over 1 year ago in reply to Matt Qi

TI__Guru**** 181481 points

What does the power source look like?

0 Matt Qi over 1 year ago in reply to Tom Hendrick

TI__Expert 4510 points

Hi Tom,

The power source seems no abnormal:

And my customer found that the reference output drops, when they are reading the 0x0 register.

Could you help check what is the usage of the 0x0 register?

Thanks for your time and effort.

Best Regards,

Matt.

0 Tom Hendrick over 1 year ago in reply to Matt Qi

TI__Guru**** 181481 points

Hi Matt,

Can you explain what you mean by 'reading the 0x0 register'? Are they actually setting the PD bits to 00? If so, they are turning off the internal reference.

0 Matt Qi over 1 year ago in reply to Tom Hendrick

TI__Expert 4510 points

Hi Tom,

This means reading 0x00 address. And they found that once they apply reading 0x00 address, the internal reference voltage will drop.

And they have cancelled this action. The system operates well.

But they still wonder why this action will result in the reference voltage dropping?

Is there any mechanism?

Thanks for your time and effort.

Best Regards,

Matt.

+1 Tom Hendrick over 1 year ago in reply to Matt Qi

TI__Guru**** 181481 points

It sounds like they are turning off the internal reference, which would explain the drop.

0 Matt Qi over 1 year ago in reply to Tom Hendrick

TI__Expert 4510 points

Hi Tom,

Thanks for your great support!

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