AK8996 Datasheet, PDF (3/74 Pages) Asahi Kasei Microsystems – Pressure Sensor Interface IC

[AK8996/W]
Overview
The AK8996 is a pressure sensor interface IC that 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 temperature drift, along with
a set of bridge voltages and temperature drift, including characteristics of the AK8996.
The internal compensation circuit is accomplished through DACs, with 4-bit and 7-bit resolution to adjust
offset voltage of the sensor, and the secondary characteristics compensator for the associated
temperature drift, coupled with 9-bit resolution to adjust the span voltage and another secondary
characteristics compensator for its associated temperature drift. Depending on the application, the internal
EEPROM values can be pre-configured to enable adjustment of the reference sensitivity and the output
reference voltage. For the adjustment procedure, see the sections on "Adjustment Sequence" and
"Functional Description".
Depending on the application, the AK8996’s internal EEPROM values can be preconfigured to enable
adjustment of the reference sensitivities and output reference voltages. Sampling frequencies can be
switched between 100Hz, 1kHz, 2kHz and 10.24kHz using the internal EEPROM data.
The AK8996 is provided with a pressure detection circuit. If the applied pressure exceeds the defined
voltage threshold at the PTH terminal, a high-level signal is output on the DET pin. The threshold can be
adjusted by the internal EEPROM data. The AK8996 is also provided with a self-diagnostic function. Upon
power-up or at initial operation immediately after exiting standby mode, this self-test feature checks for the
required value at the output (VOUT pin), and if an expected value is not available, the output is assumed to
be anomalous and a high-level signal is output on the DET pin, in the same manner as with the pressure
detection.
MS1055-E-02
3
2011/12