User's Manual
Table Of Contents
- 1 GENERAL DESCRIPTION
- 2 FUNCTIONAL DESCRIPTION
- 2.1 Simplified firmware flow chart and block diagram
- 2.2 Pin out
- 2.3 Pin description and operational characteristics
- 2.4 Absolute maximum ratings (non operating)
- 2.5 Maximum ratings (operating)
- 2.6 Power management and voltage regulators
- 2.7 Configuration
- 2.8 Radio telegram
- 2.9 Transmit timing
- 2.10 Charging circuitry
- 2.11 Energy consumption
- 3 APPLICATIONS INFORMATION
- 4 AGENCY CERTIFICATIONS
USER MANUA
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© 2010 EnOcean | www.enocean.com STM 31x / STM 31xC User Manual V0.6 | Page 18
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STM 31X / STM 31XC
2.10 Charging circuitry
The figure below shows the internal charging circuit. It is controlled via the WXODIO pin of
EO3000I which switches according to the status of the internal threshold detector. For de-
tails please refer to our Dolphin Core Description documentation.
An external 3 V battery can be connected at VDD (STM 312 only) or at VGC.
2.11 Energy consumption
Current Consumption of STM 31x
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.
0.00001
0.0001
0.001
0.01
0.1
1
10
100
0 1020304050607080 90100
Time [ms]
C u rre n t [mA]