AH31
Humidity & Temperature
Sensmitter
_ 2% Accuracy
_ Fully calibrated, digital serial output (SPI)
_ No external components required
_ Ultra low power consumption when
pulsed readout
_ Fast RH response time (4 sec. typical 1/e)
_ Small size
_ Fully interchangeable
_ Immersible
Advance Information as of September 2001
AH31 Product Summary
The AH31 is a Relative Humidity and Temperature Multi
Sensor Module comprising a calibrated digital output.
Application of industrial CMOS processes with
customized post processing (CMOSens錚?technology)
ensures highest reliability and excellent long term
stability. The device includes two calibrated
microsensors for relative humidity and temperature
which are seamlessly coupled to an amplification, analog
to digital conversion and serial interface circuit on the
same chip. This results in superior signal quality, a fast
response time and absolute insensitivity to external
disturbances even immersing the sensmitter into
chemically non-reactive liquids e.g. water, does not
result in any problems.
Each sensmitter is then 2*2 point calibrated in a pre-
cision humidity chamber and the calibration coefficients
are burnt into the OTP memory.
These coefficients are used internally during
measurement to calibrate the signals from the sensors.
This leads to a full interchangeability of the device by
keeping the accuracy given in the specifications.
The unidirectional SPI compliant 3-wire serial interface
allows easy and fast system integration. Its small
(11x8x3.5mm) size and low power consumption makes it
the ultimate choice for even the most demanding
applications including instrumentation, medical
equipment, heating, ventilation and air conditioning
systems (HVAC), portable consumer electronics,
automotive and battery-operated controllers.
The device is supplied in a surface-mountable ball grid
array (BGA) package.
AH31 Single Chip Relative Humidity and Temperature Sensor Module (CMOSens
TM
technology)
CALIBRATION
M EMO RY
SERIAL NUMB ER
MEM ORY
% RH
SENSOR
SIG NAL
CONDITIONING
M ISO
A/D
CO NVERSIO N
SPI
INTERFACE
&
CONTROL
CIRCUITS
SIG NAL
CO NDITIONING
/CS
SCK
CLK
PD
VDD
GND
A/D
CONVERSIO N
TEMP.
SENSOR
www.sensirion.com
Sensirion, Eggb眉hlstr. 14, 8052 Z眉rich, Switzerland, Tel: +41 1 306 40 00, Fax: +41 1 306 40 30
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