LTC2497 Linear Technology, LTC2497 Datasheet - Page 19

• Manufacturer Part Number: LTC2497
• Description: 16-Bit 8-/16-Channel ADC
• Manufacturer: Linear Technology

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APPLICATIONS INFORMATION
a Stop command. The following conversion begins after
all 24 bits are read out of the device or after a Stop com-
mand. The following conversion will be performed using
the newly programmed data.
Discarding a Conversion Result and Initiating a New
Conversion with Optional Write
At the conclusion of a conversion cycle, a write cycle
can be initiated. Once the write cycle is acknowledged, a
Stop command will start a new conversion. If a new input
channel is required, this data can be written into the device
and a Stop command will initiate the next conversion (see
Figure 7).
Synchronizing Multiple LTC2497s with a Global
Address Call
In applications where several LTC2497s (or other I
delta-sigma ADCs from Linear Technology Corporation)
are used on the same I
chronized through the use of a global address call. Prior
SDA
SCL
S
2
ALL LTC2497s IN SLEEP
C bus, all converters can be syn-
GLOBAL ADDRESS
LTC2497
Figure 8. Synchronize Multiple LTC2497s with a Global Address Call
LTC2497
W ACK
2
WRITE (OPTIONAL)
C
DATA INPUT
to issuing the global address call, all converters must have
completed a conversion cycle. The master then issues a
Start, followed by the global address 1110111, and a write
request. All converters will be selected and acknowledge
the request. The master then sends a write byte (optional)
followed by the Stop command. This will update the chan-
nel selection (optional) and simultaneously initiate a start
of conversion for all delta-sigma ADCs on the bus (see
Figure 8). In order to synchronize multiple converters
without changing the channel, a Stop may be issued after
acknowledgement of the global write command. Global
read commands are not allowed and the converters will
NAK a global read request.
Driving the Input and Reference
The input and reference pins of the LTC2497 are connected
directly to a switched capacitor network. Depending on
the relationship between the differential input voltage and
the differential reference voltage, these capacitors are
switched between these four pins. Each time a capacitor
is switched between two of these pins, a small amount
…
P
LTC2497
CONVERSION OF ALL LTC2497s
2497 F08
LTC2497
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