AK8998 Datasheet, PDF (51/59 Pages) Asahi Kasei Microsystems – Preliminary

[AK8998/W/D]
6.1.2) Reference Voltage Generator EEPROM
k) VREF voltage adjustment (EEPROM name: VREF)
EEPROM for adjusting the AK8998 reference voltage. Perform an adjustment to attain the
reference voltage of 1000 mV (See Recommended Connection Examples for Components).
∆VREF3/5 in the table below indicates a value varying with the setup values of the EEPROM.
∆VS3/5 represents the values of ∆VREF3/5 multiplied by two and four, respectively. The ratio is
benchmarked to 1000mV (VREF ideal value) as 100% (Ratio = (∆VREF3/5) /1000[mV]*100[%]).
Address : 0E hex D[2:0]=EVR[2:0]
EVR[2:0]
Ratio VDD: 3V, 3.3V mode
Dec Hex Bin
(%)
∆VREF3
(mV)
∆VS3
(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
∆VREF5 ∆VS5
(mV)
(mV)
-40
-160
-30
-120
-20
-80
-10
-40
0
0
+10
+40
+20
+80
+30
+120
Comments
Default
l) IREF current adjustment (EEPROM name: IREF)
EEPROM for adjusting the AK8998 reference current. The external resistor (1MΩ) is connected to
VOUT pin. Reference current is supplied to external resistor, and it adjusts so that the voltage across
the both ends of external resistor may be set to 1.0V (See Recommended Connection Examples for
Components).
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[3:0]=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
Comments
Default
MSxxxxx-E-00
- 48 -
2011/12