AD7294 Analog Devices, AD7294 Datasheet - Page 40

• Manufacturer Part Number: AD7294
• Description: 12-Bit Monitor and Control System with Multichannel ADC, DACs, Temperature Sensor, and Current Sense
• Manufacturer: Analog Devices

Specifications of AD7294

• Resolution (bits): 12bit
• # Chan: 9
• Sample Rate: 200kSPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: (Vref) p-p,2 V p-p,Uni (Vref),Uni (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: CSP

AD7294
AUTOCYCLE MODE
The
programmable sequence of channels making it the ideal mode
of operation for system monitoring. These conversions take
place in the background approximately every 50 µs, and are
transparent to the master. Typically, this mode is used to
automatically monitor a selection of channels with either the
limit registers programmed to signal an out-of-range condition
via the alert function or the minimum/maximum recorders
tracking the variation over time of a particular channel. Reads
and writes can be performed at any time (the ADC Result
Register 0x01 contains the most recent conversion result).
On power up, this mode is disabled. To enable this mode, write
to Bit D12 in the configuration register (0x09) and select the
desired channels for conversion in the channel sequence
register (0x08).
If a command mode conversion is required while the autocycle
mode is active, it is necessary to disable the autocycle mode before
AD7294
can be configured to convert continuously on a
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proceeding to the command mode. This is achieved either by clear-
ing Bit D12 of the configuration register or by writing 0x00 to the
channel sequence register. When the command mode conversion is
complete, the user must exit command mode by issuing a stop
condition before reenabling autocycle mode.
When switching out of autocycle mode to command mode,
the temperature sensor must be given sufficient time to settle
and complete a new temperature integration cycle. Therefore,
temperature sensor conversions performed within the first
500 ms after switching from autocycle mode to command mode
may result in false temperature high and low alarms being
triggered. It is recommended to disable temperature sensor
alarms for the first 500 ms after mode switching by writing
0x400 to the DATA
DATA
be reconfigured to the desired alarm level once the 500 ms has
elapsed. Alternatively, temperature alerts triggered during the
first 500 ms after mode switching should be ignored.
HIGH
register T
LOW
SENSE
T
x. The temperature sensor alerts should
SENSE
x register and 0x3FF to the
Data Sheet