From the knowledge base articles, there is an example for calculating the power draw.
There seems to be a discrepancy with regards to the LED power calc in AN950 (LED current *48.8us * gain), as opposed to knowledgebase (LED current *24.4us*gain).
The knowledgebase seems correct based on the the standard 24.4uSec LED period. (and knowledgebase example assumes HW_GAIN = 0).
Can you confirm?
with the appropriate snippet:
The si1153 sensor will perform 2 back-to-back measurements, one with the LED on and the other with the LED off. Therefore, if we assume integration time is set to default and LED current is set to maximum 354mA, the total power consumption will be:
I = (155us * 4.5mA + 48.8us * 525uA + 2* 24.4us * 525uA + 24.4us * 354mA) * Fs
where Fs is the sampling frequency of the measurement.
This references app note AN950
With this snippet:
6.4 LED Power
On each proximity measurement, the LED current is on for 48.8 μs times the gain. Thus, for each proximity channel, the LED duty cycle
DC LED = 48.8μs × 2HW_GAIN
The LED on time is the same as the integration time which can be adjusted by both HW_GAIN and DECIM settings. 24.4us is the minimum setting (DECIM=3, HW_GAIN=0). I believe the KBA is referring to that setting. However, if DECIM is set to 0 (by default), the integration time will be 48.8us (HW_GAIN=). The application note uses that number as an example.
Your comment was trunctated:
However, if DECIM is set to 0 (by default), the integration time will be 48.8us (HW_GAIN=)."
That is for HW_GAIN=0?
This area of the app note and the example are somewhat confusing, maybe some clarification in the documentation would help, espcially use of integration time, vs measurement time, versus LED on time. With 2X internal measurements per requested measurement, LED is only one for the second internal measurement.