AS8501 Datasheet, PDF (19/40 Pages) ams AG – High precision voltage and current measurement sensor interface

AS8501 - Preliminary Data Sheet
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subregister MM: chopping ratio bit, Registers CRA, CRB
Nr.
MM
mm NOTE
0
4
0
1
8
1
2
1
x ¹⁾
Notes:
1) For c=0 and d=0 , chopping and dechopping is switched off and every cycle is active regardless
of mm, i.e. the sampling frequenzy is higher by a factor of 4
subregister CRN: averaging bits ( 4 bits), registers CRA,CRB
Nr.
R2
n3 n2 n1 n0 NOTE
0
1
0000
1
2
0001
2
4
0010
3
8
0011
4
16
0100
5
32
0101
6
64
0110
7
128
0111
8
256
1000
9
512
1001
10
1024
1010
11-14
Reserved for test
1 x x x ¹⁾
15
raw mode
1 1 1 1 ²⁾
Note:
1) _{combinations from B to E are reserved for test}
2) _{this mode delivers the AD-values without calibration and averaging but multiplied by a factor which is dependent on the}
setting of the oversampling ratio. It can be used for high resolution measurements of very low signals since it eliminates
the internal rounding error.
The ratio between raw result (Nr) and normal result (Nn) is given by: Nr/Nn = 2^(11+x)/CAL where x=6 for R=128 and x=3
for R=64. CAL is the calibration constant used.
7.5.4 CRB measurement channel B configuration register ( 17 bits )
Nr.
Bits 16 15 14 13 12 11 10 9 8 7
6
5 43
0 CRB bit cu2 cu1 cu0 M5 M4 M3 M2 M1 g1 g0
f
r mm n3
names
1 Defaults 0 0 0 0 1 1 0 0 0 1
1
0 00
2 subreg.
CRU
CRM
GN
OSF OSR MM
Notes:
1) _{This register defines the measurement channel B configuration, the functions of the subregisters are the same as}
described above for measurement channel A
2) _{Default power-up state before any setting}
3) _{In this mode the chip cannot measure the current sensing input RSHH-RSHL, therefore M1=0 for all settings}
2 1 0 NOTE
n2 n1 n0 ^{1), 3)}
00
CRN
0 ²⁾
Revision 1.1, 04-April-06
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