PAS CO2 power up sequence, minimum measurement interval

[h_nakamura]

Hi,

What is the minimum time for 3.3V ON to 12V ON in the 3.3V / 12V power-on sequence?
According to AN_2106_PL38_2107_132213, the order is written, but the interval is not described.

Measurement mode configuration register (MEAS_CFG) Is it possible to measure in a time shorter than the minimum measurement interval of 5 seconds in continuous mode when OP_MODE is used in Single-shot mode? ex. 2s

We are planning to control both 3.3V / 12V power supplies to OFF / ON / OFF in order to reduce power consumption, but is it okay to repeat OFF / ON / OFF at short intervals (example: 5 seconds)? Is there any effect on the life of the IC?

Best regards,

[Neo_Lu]

Hi, h_nakamura

According to AN_2011_PL38_2011_134235(Programming guide for XENSIVTM PAS CO2) page 10 to page 11,

https://www.infineon.com/dgdl/Infineon-programming_guide_PAS_CO2_evaluationkit-ApplicationNotes-v02_... 

after one measurement sequence the emitter needs at least 10 s to cool down. Measurement rate values in continuous mode below 5 s are treated as being equal to 5 s. For single-shot measurement make sure to delay the following measurement sequence by at least 10 s for accurate readings. 

So it not suggests measure in a time shorter than the minimum measurement interval of 5 seconds in continuous mode when OP_MODE is used in Single-shot mode. ex. 2s

It also not suggests repeat OFF / ON / OFF at short intervals (example: 5 seconds).

[h_nakamura]

Hi Neo_Lu,
Thanks for your prompt reply.
I confirmed AN and I understood your comment.
Isn't there the specification regarding minimum time between 3.3V on to 12V on and 12V off to 3.3V off, is it?  
Best regards,

[Deepa_V · Accepted solution]

Hi @h_nakamura ,

There is no time specification stated between the power on and power off times of 3.3V and 12V supply. It is specified in the initialization sequence to follow one step after the other only suggesting optimal operation. Also, it is advised that atleast a few seconds interval is provided. 

Best regards,

Deepa