AK8998 Datasheet, PDF (42/59 Pages) Asahi Kasei Microsystems – Preliminary

[AK8998/W/D]
a) Offset voltage adjustment (EEPROM names: OCR, OCF)
Rough adjustment should be performed first, followed by a fine adjustment for the offset voltage.
The content of the adjustment EEPROMs are shown here.
a-1) Offset voltage rough adjustment (OCR)
The offset voltage is adjusted roughly.
The offset adjustment voltage varies ratiometrically with respect to the supply voltage.
The ratio in the table below is benchmarked to a VOUT output of 4800 mV (@VDD: 5V) as 100%
(ratio = (Offset voltage @VDD: 5V)/4800[mV]*100[%]).
Address : 00 hex D[3:0]=EOCR[3:0]
EOCR [2:0]
Ratio
VDD:3V
EOCR EOCR
Dec Hex
Bin
(%)
[3]=0
[3]=1
(mV)
(mV)
00
000
0.00
0
0
11
001
33.33 800
-800
22
010
66.67 1600
-1600
33
011
100.00 2400
-2400
44
100
133.33 3200
-3200
55
101
166.67 4000 -4000
66
110
200.00 4800
-4800
77
111
233.33 5600
-5600
VDD:5V
EOCR EOCR
[3]=0 [3]=1
(mV)
(mV)
0
0
1600
-1600
3200
-3200
4800
-4800
6400
-6400
8000 -8000
9600
-9600
11200 -11200
Comments
Default
a-2) Offset voltage fine adjustment (OCF)
The offset voltage is adjusted finely.
The offset adjustment voltage varies ratiometrically with respect to the supply voltage.
The ratio in the table below is benchmarked to a VOUT output of 4800mV (@VDD: 5V) as 100%
(ratio = (Offset voltage @VDD: 5V)/4800[mV]*100[%]).
Address : 01hex D[7:0]=EOCF[7:0]
EOCF [6:0]
Ratio
VDD:3V
EOCF EOCF
Dec Hex
Bin
(%)
[7]=0
[7]=1
(mV)
(mV)
0 00 0000000
0
0
0
1 01 0000001 0.17
4
-4
：
：
：
：
：
：
15 0F 0001111 2.50
60
-60
16 10 0010000 2.67
64
-64
：
：
：
：
：
：
31 1F 0011111 5.17
124
-124
32 20 0100000 5.33
128
-128
：
：
：
：
：
：
63 3F 0111111 10.50 252
-252
64 40 1000000 10.67 256
-256
：
：
：
：
：
：
126 7E 1111110 21.00 504
-504
127 7F 1111111 21.17 508
-508
VDD:5V
EOCF EOCF
[7]=0 [7]=1
(mV)
(mV)
0
0
8
-8
：
：
120
-120
128
-128
：
：
248
-248
256
-256
：
：
504
-504
512
-512
：
：
1008
-1008
1016
-1016
Comments
Default
MSxxxxx-E-00
- 39 -
2011/12