Table of Contents
Advertisement
User Manual EE895
3.5
Pin Description
Pin 1 - VCC_EM
Power supply for the infrared lamp (IR-L). For optimizing of the energy consumption such as in battery-powered
devices, the IR-L can be powered separately.
The IR-L does not have to be powered continuously, as it needs power supply during the measurement cycle t
meas
only, see Fig. 7. Between the measurement cycles the current consumption of IR-L is approx. 0.1 µA.
Pin 2 - VCC_IO
Power supply for the microcontroller and the digital functional blocks.
Pin 3 – EN (Enable)
For battery-powered devices the user can optimize the energy consumption controlling the status of the EN pin by
an external host controller.
When the EN pin is pulled-down to the logic Low 0 (≤0.4 V), the internal voltage regulator of EE895 is switched
off and the current consumption is typically 1 µA (max 2 µA).
When pulled-up to the logic state High (≥0.9 V), the EE895 operates normally.
If the energy consumption of EE895 is not relevant, the EN pin shall be connected to VCC_IO.
The EN pin may not be left open.
Pin 6 – RDY (Data ready)
During the measurement cycle (
), when CO
, T and p are measured and processed, the pin RDY is in logic
tmeas
2
state High. As soon as data is available for read out, the pin RDY goes to logic state Low. The falling edge at this
pin indicates that measured data is available for reading, see Fig. 5.
If used, an external pull-up resistor is required. If not used, the RDY pin may be left open.
Fig. 5
Timing details (see also chapter 4.5.3. CO
Parameter Settings)
2
Miniature Sensor Module for CO
, Temperature and Barometric Pressure | 9
2
Advertisement
Table of Contents
