AK8996 Datasheet, PDF (34/74 Pages) Asahi Kasei Microsystems – Pressure Sensor Interface IC

[AK8996/W]
7.1 Pressure Sensor Offset Temperature Drift Measurement
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:0h, data OTSW[0]:1h,
data STSW[0]:1h).
Measure the VOUT pin voltage at a pressure of 0kPa.
7.2 Pressure Sensor Sensitivity Temperature Drift Measurement
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:0h, data OTSW[0]:1h,
data STSW[0]:1h).
Measure the VOUT pin voltage (Vp72) at pressure e.g., +100kPa.
As necessary, measure the VOUT pin voltage at pressure e.g., -100kPa.
7.3 AK8996 Offset Secondary Temperature Characteristics Measurement (g*aT^2+g*bT+g*c)
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:1h, data OTSW[0]:0h,
data STSW[0]:1h, 2ND[1:0]:1h).
Measure the VOUT pin voltage.
7.4 AK8996 Offset Primary Temperature Characteristics Measurement (dT + e)
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:1h, data OTSW[0]:0h,
data STSW[0]:1h, 2ND[1:0]:2h).
Measure the VOUT pin voltage.
7.5 AK8996 Sensitivity Secondary Temperature Characteristics Measurement
(g*aT^2+g*bT+g*c)
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:2h, data OTSW[0]:1h,
data STSW[0]:0h, 2ND[1:0]:1h).
Measure the VOUT pin voltage.
7.6 AK8996 Sensitivity Primary Temperature Characteristics Measurement (dT + e)
Configure adjustment mode 2 register (C address: 01h data INSW[1:0]:2h, data OTSW[0]:1h,
data STSW[0]:0h, 2ND[1:0]:2h).
Measure the VOUT pin voltage.
8. Calculating the Secondary Characteristics from the Section 7 Measurement Results
Calculate α off, β off and γ off values from the pressure sensor offset temperature measurement
results.
Calculate α ga, β ga, and γ ga values from the pressure sensor sensitivity temperature
measurement results.
Values for g*a, g*b+d and g*c+e are known from the AK8996 temperature drift measurement
results.
Zero order coefficient γ and g*c + e are already adjusted in Sections 5 and 6, so no further
adjustment is required here.
For offset and sensitivity,
Make an adjustment to achieve α = g*a.
Make an adjustment to achieve β = g*b + d.
MS1055-E-02
34
2011/12