Datasheet

LTC2481
18
2481fc
APPLICATIONS INFORMATION
Continuous Read/Write
Once the conversion cycle is concluded, the LTC2481 can
be written to then read from, using the repeated Start (Sr)
command.
Figure 7 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 24
bits are read out of the device or after the STOP command
and uses the newly programmed confi guration data.
Discarding a Conversion Result and Initiating a New
Conversion with Optional Confi guration Updating
At the conclusion of a conversion cycle, a Write cycle
can be initiated. Once the Write cycle is acknowledged,
a stop (P) command initiates a new conversion. If a new
confi guration is required, this data can be written into the
device and a stop command initiates a new conversion,
see Figure 8.
Synchronizing Multiple LTC2481s with the Global
Address Call
In applications where several LTC2481s are used on the
same I
2
C bus, all LTC2481s can be synchronized with the
global address call. To achieve this, fi rst all the LTC2481s
must have completed the conversion cycle. The master
issues a Start, followed by the LTC2481 global address
1110111 and a Write request. All LTC2481s will be selected
and acknowledge the request. The master then sends
the write byte (Optional) and ends the Write operation
with a STOP. This will update the confi guration registers
(if a write byte was sent) and initiate a new conversion
simultaneously on all the LTC2481s, as shown in Figure 9.
In order to synchronize the start of conversion without
affecting the confi guration registers, the Write operation
can be aborted with a STOP. This initiates a new conversion
on all the LTC2481s without changing the confi guration
registers.
Figure 5. The LTC2481 Conversion Sequence
Figure 6. Consecutive Reading at the Same Confi guration
Figure 7. Write, Read, Start Conversion
S ACK DATA Sr DATA TRANSFERRING P
SLEEP DATA INPUT/OUTPUT CONVERSIONCONVERSION
7-BIT ADDRESS
R/W
2481 F05
7-BIT ADDRESS
CONVERSION CONVERSION
CONVERSION
SLEEP SLEEPDATA OUTPUT DATA OUTPUT
7-BIT ADDRESSSSRRACK ACKREAD READPP
2481 F06
7-BIT ADDRESS
CONVERSION CONVERSIONADDRESSSLEEP DATA OUTPUTDATA INPUT
7-BIT ADDRESSS RW ACK ACKWRITE Sr PREAD
2481 F08