ICs for Pressure Sensors
A pressure sensor interface IC features compensation for temperature drift and sensor variation.
It is designed to excite and interface to a bridge sensor. Variations in the sensor can be corrected
via compensation values stored in integrated non-volatile memory (EEPROM).
Compensation values are obtained from measurement results for a set of offset voltages and
their temperature drift, along with a set of bridge voltages and their temperature drift,
including characteristics of IC. Output signal is a ratiometric analog voltage.
The IC has a pressure detection circuit. The detection threshold can be set by built-in DAC or
the output pin(PTH).
AK8996 perform high precision temperature compensation, and adjust the temperature characteristics of offset voltage and span voltage with the second order characteristics compensator.
AK8999A has the 1st order coefficient or the quasi 2nd order coefficient by piecewise linear approximation.
Since an internal resistor of 32kΩ(AK8996)/146kΩ(AK8999A) is built in the the output stage, Band-limiting is realized with a combination of external capacitors. The internal LPF (fc: 1kHz, 500Hz, 250Hz) is available by the EEPROM data in AK8999A. In this case the external capacitors are not needed.
AK8996 has SPI serial interface (SCLK, SDI, CS) which can directly access to MCU. AK8999A has the original two-wire serial interface (CSCLK, VOUT).
|AK8996/W||Wafer / UQFN16||-40 to 105|
2.2 to 3.6 /
4.5 to 5.5
|-40 to 105||2.7 to 3.3 /|
2.97 to 3.63 /
4.5 to 5.5
note1: The 1st order coefficient or the quasi 2nd order coefficient by piecewise linear approximation (1st order independent coefficients
can be set for high and low temperature side on the basis of 25°C)
□ Washing machine
□ Scale (Weighing machine)
□ Pressure switch
□ Machine tools etc.