LTC2309
APPLICATIONS INFORMATION
Continuous Read/Write
2
the same I C bus, all converters can be synchronized
through the use of a global address call. Prior to issu-
ing 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 ac-
knowledge the request. The master then sends a write
byte(optional)followedbytheStopcommand.Thiswill
update the channel selection (optional) and simultane-
ously initiate a conversion for all ADCs on the bus (see
Figure 11). In order to synchronize multiple converters
without changing the channel, a Stop command 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.
Oncetheconversioncycleiscomplete,theLTC2309can
be written to and then read from using the Repeated
Start (Sr) command. Figure 10 shows a cycle which
begins with a data Write, a repeated Start, followed
by a Read and concluded with a Stop command. The
following conversion begins after all 16 bits are read
out of the device or after a Stop command. The fol-
lowing conversion will be performed using the newly
programmed data.
Synchronizing Multiple LTC2309s with a Global
Address Call
2
InapplicationswhereseveralLTC2309sorotherI CSAR
ADCs from Linear Technology Corporation are used on
S 7-BIT ADDRESS W ACK WRITE Sr 7-BIT ADDRESS R ACK READ P
CONVERSION
NAP
DATA OUTPUT
CONVERSION
DATA
OUTPUT
CONVERSION
2309 F10
Figure 10. Write, Read, Start Conversion
SCL
SDA
LTC2309
LTC2309
LTC2309
S GLOBAL ADDRESS W ACK WRITE (OPTIONAL) P
CONVERSION NAP DATA OUTPUT CONVERSION OF ALL LTC2309s
2309 F11
Figure 11. Syncrhonous Multiple LTC2309s with a Global Address Call
2309f
16
Linear [ Linear ]
