9 Important Notes
Dummy Conversions after Power-up
9.1
After power-up the ADC’s logic will be in a random state and may not perform correctly. This has two
consequences:
1. The first conversion results are not valid and should be ignored.
2. The ADC starts in a mode that prevents a correct start of the sequencer.
Therefore, two dummy conversions are required after each power-up, whose results should be ignored.
Use the ADC Conversion Start Register (ADCCONV) Register to perform the dummy conversions.
If the sequencer is to be used, these two dummy conversions are absolutely necessary.
If one of TEWS TECHNOLOGIES software drivers is used, these two dummy conversions are already included.
Open Multiplexer Inputs
9.2
Unused Multiplexer inputs can pick up stray signals which are injected into the device’s substrate. This turns on
spurious substrate devices which badly degrade the performance of the whole multiplexer device.
Make sure that all unused analog input pins are tied to the analog ground signal level (or any other valid
signal level within the analog input voltage range). This is required even if the unused channels are
turned off by software.
TPMC851 User Manual Issue 1.0.9
Page 65 of 65