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TMP121: What is optimal Low-power control implementation for the TMP121 for e.g. 1Hz sample interval

Part Number: TMP121

Hi there,

I want to readout the TMP121 every 1 second and I want to verify if my approach is correct when going for low power use. In order to do this I'm missing relevant information from the datasheet so I will first do some assumptions in the form of questions. Can you tell me if these assumptions are correct?

1) a New conversion always starts when CS_N becomes inactive (high)?

2) The TMP121 has an internal timer that is triggered on CS_N becoming inactive which is also used for automatic periodic conversion?

3) You do not need to wait for the maximum trigger period (640ms) to start a new conversion manually. Therefor the minimum conversion period (not conversion time) can be around 320ms conv time (maximum) + spi readout time 1u6s (minimum)

So for a low power readout at 1Hz intervals with e.g. sck at 5MHz I would do:

1) reset value of CS_N = low

2) activate CS_N to start conversion

3) deactivate CS_N after 320ms to stop conversion and start readout + start analog shutdown timer

4) keep CS_N low to force shutdown until analog shutdown timer is 1s - 320ms = 680ms

5) repeat from 2)

Does this seem correct or am I missing something?

With regards,

Sander Ter Burg