User's Manual

USER MANUAL 1.34
© 2013 EnOcean | www.enocean.com STM 300 / STM 300C / STM 300U User Manual | Page 20/42
STM 300 / STM 300C / STM 300U
3.11 Energy consumption
Current Consumption of STM 300
Charge needed for one measurement and transmit cycle: ~130 µC
Charge needed for one measurement cycle without transmit: ~30 µC
(current for external sensor circuits not included)
Calculations are performed on the basis of electric charges because of the internal linear
voltage regulator of the module. Energy consumption varies with voltage of the energy
storage while consumption of electric charge is constant.
From these values the following performance parameters have been calculated:
Wake
cycle
[s]
Transmit
interval
Operation Time
in darkness [h]
when storage
fully charged
Required reload
time [h] at 200
lux within 24 h
for continuous
operation
24 h operation
after 6 h
illumination
at x lux
Illumina-
tion level
in lux for
continuous
operation
Current
in µA
required
for con-
tinuous
operation
1
1
0.5
storage too small
storage too small
5220
130.5
1
10
1.7
storage too small
storage too small
1620
40.5
1
100
2.1
storage too small
storage too small
1250
31.3
10
1
5.1
storage too small
storage too small
540
13.5
10
10
16
21
storage too small
175
4.4
10
100
20
16.8
storage too small
140
3.5
100
1
43
7.8
260
65
1.6
100
10
98
3.6
120
30
0.8
100
100
112
3
100
25
0.6
Assumptions:
 Storage PAS614L-VL3 with 0.25 F, Umax=3.2 V, Umin=2.2 V, T=25°C
 Consumption: Transmit cycle 100 µC, measurement cycle 30 µC
 Indoor solar cell, operating values 3 V and 5 µA @ 200 lux fluorescent light
(e.g. ECS 300 solar cell)
 Current proportional to illumination level (not true at very low levels!)
These values are calculated values, the accuracy is about +/-20%!
0.00001
0.0001
0.001
0.01
0.1
1
10
100
0 10 20 30 40 50 60 70 80 90 100
Time [ms]
Current [mA]