Data Sheet

HYGROCHIP 3/3
DIGITAL HUMIDITY SENSOR
PROTOCOL DESCRIPTION I2C
All mechanical dimensions are valid at 25°C ambient temperature, if not differently indicated. B All data except the mechanical dimensions only have information purposes and are not to be understood as assured characteristics. B Technical changes without previous announcement as well as mistakes reserve. B The information on this data sheet was examined carefully and will be accepted as correct; No liability in case of mistakes. B Load with extreme values during a longer period can affect the reliability.
Released 12/2011 Rights reserved for change in technical data!
Scaling of measurement values
T
raw
and rH
raw
are the digital 16 bit values submit-
ted by the sensor.
The first top bits are status bits with following rele-
vance:
Bit 15: CMode Bit, if 1 – element is in command
mode
Bit 14: Stale bit, if 1 – no new value has been cre-
ated since the last reading.
To mask the 2 top status bits in a 16 bit value, it will
be linked logically with 3FFF and AND. The remain-
ing 14 bit represents the measured value.
The masked value data now have to be scaled into
physical measurement units:
T [°C] = (165 / 2^14) * T
raw
- 40
Example:
0x0 complies with -40°C
0x3FFF complies with +125°C
T
raw
= 0x0000….0x3FFF (Hex) or 0…..16383 (Dec)
Humidity values will be calculated as follows:
rH [%] = (100 / 2^14) * rH
raw
Example:
0x0 complies with - 0%rH
0x3FFF complies with 100%rH
rH
raw
= 0x0000….0x3FFF(Hex) or 0…..16383 (Dec)
C-Code examples are available upon request.
AHHYT-I2C_E1.1