AK8999A Datasheet, PDF (60/68 Pages) Asahi Kasei Microsystems – Pressure Sensor Control IC

CONFIDENTIAL
[AK8999A/AW/AD]
k) VREF voltage adjustment (EEPROM name: VREF)
This EEPROM is used for adjusting the AK8999A reference voltage. Perform an adjustment to attain the
reference voltage of 1000mV (See “Recommended External Circuits”).
ΔVREF3/5 in the table below indicates a value varying with the setup values of the EEPROM.
ΔVS3/5 represents the values of ΔVREF3/5 multiplied by two and four, respectively. The ratio in the
table below is benchmarked to 1000mV (VREF ideal value) as 100%
(Ratio = (ΔVREF3/5) /1000[mV]*100[%]).
Address : 0F hex D[2:0] = EVR[2:0]
EVR[2:0]
Ratio VDD:3V, 3.3V mode
ΔVREF3
Dec Hex Bin (%)
(mV)
ΔVS3
(mV)
-4 4 100 -4
-40
-80
-3 5 101 -3
-30
-60
-2 6 110 -2
-20
-40
-1 7 111 -1
-10
-20
0 0 000 0
0
0
1 1 001 1
+10
+20
2 2 010 2
+20
+40
3 3 011 3
+30
+60
VDD:5V
ΔVREF5 ΔVS5
(mV)
(mV)
-40
-160
-30
-120
-20
-80
-10
-40
0
0
+10
+40
+20
+80
+30
+120
Description
Default
l) IREF current adjustment (EEPROM name: IREF)
This EEPROM is used for adjusting the AK8999A reference current. The external resistor (1M) is
connected to VOUT pin. The reference current is adjusted so that the voltage droped by external
resistor may be set to 1.0V. (See “Recommended External Circuits”).
IREF in the table below indicates a current value with the setup values of the EEPROM.
VIREF (=IREF*1[MΩ]) is a voltage value varying with the external resistance (1MΩ) at the time of
adjustment. The ratio is benchmarked to 1.0µA (IREF ideal value) as 100%
(Ratio = (IREF-1.0 [µA])/1.0 [µA]*100[%]).
Address : 0F hex D[7:4] = EIR[3:0]
EIR[3:0]
Ratio
Dec Hex Bin
(%)
-8 8 1000
-17.0
-7 9 1001
-15.2
-6 A 1010
-13.4
-5 B 1011
-11.5
-4 C 1100
-9.5
-3 D 1101
-7.3
-2 E 1110
-5.0
-1 F 1111
-2.6
0
0
0000
0.0
1
1
0001
2.8
2
2
0010
5.7
3
3
0011
8.8
4
4
0100
12.2
5
5
0101
15.9
6
6
0110
19.8
7
7
0111
24.1
IREF
(μA)
0.830
0.848
0.866
0.885
0.905
0.927
0.950
0.974
1.000
1.028
1.057
1.088
1.122
1.159
1.198
1.241
VIREF
(V)
0.830
0.848
0.866
0.885
0.905
0.927
0.950
0.974
1.000
1.028
1.057
1.088
1.122
1.159
1.198
1.241
Description
Default
MS1600-E-00
- 60 -
2014/05