Datasheet

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last update
November 30, 2010
reference
smtutin
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8.6 Mode 14. Brg1: resistive bridge +/- 0.25% and 2 resistors
This mode is similar to mode 13. The connection is shown in Figure 15 . The difference with mode 13 is
that the measurement range of the bridge imbalance is 0.25%. The bridge output voltage V
CD
is amplified
15 times before it is processed further. The voltages measured during each phase are indicated in Table
26 . The specifications are listed in Table 27. For the measurement of the signal V
BF
, due to the effect of
the internal connection wires of the UTI, an error of 1.2% will be caused on the result of V
AB
/ V
BF
. This
measured error depends on the supply current of the resistive bridge and temperature.
Parameter (V
DD
= 5 V) Typical value
K
2
56 s/V
V
0
0.54 V
Bridge excitation AC Vdd
excitation current (max E - F) 20 mA
Bridge resistance 250-10k
Bridge output Voltage <+/- 12,5 mV
Accuracy Vcd/Vea 10 bits (over +/- 12,5mV)
Linearity Vab/Vbf 12 bits (over +/- 12,5 mV)
Offset Vcd
<10 V
Offset Vab
<10 V
Resolution (SF=0)
< 7 V
Resolution (SF=1)
< 7 V
Table 27. Specifications of the Brg1 mode
Phase Measured voltages Output periods
1 V
offset
Toffset=N*K
2
*Voffset
2 V
ab
+V
offset
Tab= N*K
2
*(Vab+Voffset)
3 15*Vcd+V
offset
Tcd=N*K
2
*(15*Vcd+Voffset)
4 V
bf
+V
offset
Tbf= N*K
2
*(Vbf+Voffset)
5 V
ea
/32+V
offset
Tea= N*K
2
*(Vea/32+Voffset)
Table 26. Measured voltages
during the measurement of Brg1 mode