CS5523-AS(2000) 查看數據表（PDF） - Cirrus Logic
零件编号
产品描述 (功能)
生产厂家
CS5523-AS Datasheet PDF : 56 Pages
| |||
CS5521/22/23/24/28
tion of offset to occur in the 25 mV, 55 mV, and
100 mV ranges, the AIN- pin must be at the proper
common-mode-voltage as specified in ‘Common
Mode +Signal AIN+/-’ specification in the Analog
Input section (if AIN- = 0 V, NBV must be between
-1.8 V to -2.5 V). For self-calibration of offset in the
1.0 V, 2.5 V, and 5 V ranges, the inputs of the mod-
ulator are connected together and then routed to the
VREF- pin as shown in Figure 12.
For self-calibration of gain, the differential inputs
of the modulator are connected to VREF+ and
VREF- as shown in Figure 13. For any input range
other than the 2.5 V range, the converter’s gain er-
ror can not be completely calibrated out when using
self-calibration. This is due to the lack of an accu-
rate full scale voltage internal to the chips. The
2.5 V range is an exception because the external
reference voltage is 2.5 V nominal and is used as
the full scale voltage. In addition, when self-cali-
bration of gain is performed in the 25 mV, 55 mV,
and 100 mV input ranges, the instrumentation am-
plifier’s gain is not calibrated. These two factors
can leave the converters with a gain error of up to
±20% after self-calibration of gain. Therefore, a
system gain calibration is required to get better ac-
curacy, except for the 2.5 V range.
2.3.2 System Calibration
For the system calibration functions, the user must
supply the calibration signals to the converter which
represent ground and full scale. When a system offset
calibration is performed, a ground referenced signal
must be applied to the converters. See
Figures 14 and 15.
As shown in Figures 16 and 17, the user must input
a signal representing the positive full scale point to
S1
OPEN
AIN+
+
+
S2
X20
CLOSED
AIN-
-
-
Figure 11. Self Calibration of Offset (Low Ranges)
AIN+
AIN-
VREF-
S1
OPEN
+
+
X20
-
-
S2
OPEN
S4
CLOSED
Figure 12. Self Calibration of Offset (High Ranges)
AIN+
AIN-
VREF+
Reference +- VREF-
OPEN
+
+
X20
-
-
OPEN
CLOSED
CLOSED
Figure 13. Self Calibration of Gain (All Ranges)
32
External
Connections
+
+
AIN+
0V +-
X20
-
-
AIN-
CM +-
Figure 14. System Calibration of Offset (Low Ranges)
DS317F2
Share Link: 