CS5521/22/23/24/28
of the configuration register.
4) Once the CSRs are programmed, repeated conver-
sions on up to 16 Setups can be performed by is-
suing only one command byte.
5) The single conversion mode also requires only one
command, but whenever another or a different
single conversion is wanted, this command or a
modified version of it has to be issued again.
6) The NULL command is used to keep the serial port
in command mode, once it is in command mode.
the conversions MSB first. The last byte of the con-
version data word (CS5521/23 only) contains data
monitoring flags. The channel indicator (CI) bits
keep track of which physical channel was convert-
ed, and the overrange flag (OF) and the oscillation
detect (OD) bits monitor conversions to determine
if a valid conversion was performed. Refer to the
section for
more details.
The CS5521/22/23/24/28 output data conversions
in binary format when operating in unipolar mode
and in two’s complement when operating in bipolar
mode. Refer to the
section for more details.
2.5
Conversion Output Coding
The CS5521/22/23/24/28 devices output 16-bit
(CS5521/23) and 24-bit (CS5522/24/28) data con-
version words. To read a conversion word, the user
must read the conversion data FIFO. The conver-
sion data FIFO is up to 192 bits long and outputs
CS5521/23 16-Bit Output Coding
Unipolar Input
Voltage
>(VFS-1.5 LSB)
VFS-1.5 LSB
Offset
Binary
FFFF
FFFF
------
FFFE
8000
------
7FFF
0001
------
0000
0000
Bipolar Input
Voltage
>(VFS-1.5 LSB)
VFS-1.5 LSB
Two’s
Complement
7FFF
7FFF
------
7FFE
0000
------
FFFF
8001
------
8000
8000
CS5522/24/28 24-Bit Output Coding
Unipolar Input
Voltage
VFS-1.5 LSB
Offset
Binary
FFFFFF
------
FFFFFE
800000
------
7FFFFF
000001
------
000000
Bipolar Input
Voltage
>(VFS-1.5 LSB)
VFS-1.5 LSB
Two’s
Complement
7FFFFF
7FFFFF
------
7FFFFE
000000
------
FFFFFF
800001
------
800000
800000
>(VFS-1.5 LSB) FFFFFF
VFS/2-0.5 LSB
VFS/2-0.5 LSB
-0.5 LSB
-0.5 LSB
+0.5 LSB
+0.5 LSB
-VFS+0.5 LSB
<(-VFS+0.5 LSB)
-VFS+0.5 LSB
<(+0.5 LSB)
<(+0.5 LSB)
000000 <(-VFS+0.5 LSB)
Note: VFS in the table equals the voltage between ground and full scale for any of the unipolar gain ranges, or the
voltage between
±
full scale for any of the bipolar gain ranges. See text about error flags under overrange
conditions.
Table 6. Output Coding for 16-bit CS5521/23 and 24-bit CS5522/24/28
40
DS317F2
CIRRUS [ CIRRUS LOGIC ]
