Datasheet

LTC2309
17
2309fd
AppLICAtIOns InFORMAtIOn
ates a NACK signal indicating the conversion cycle is
in progress.
Continuous Read/Write
Once the conversion cycle is complete, the LTC2309
can 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. After
all 16 bits are read out, a conversion may be initiated
by issuing a STOP command. The following conver-
sion will be performed using the newly programmed
data.
S
CONVERSION NAP DATA OUTPUT CONVERSION CONVERSIONNAP DATA
OUTPUT
R ACK READ7-BIT ADDRESS P S R ACK
2309 F09
READ7-BIT ADDRESS P
Figure 9. Consecutive Reading with the Same Configuration
Continuous Read
In applications where the same input channel is sampled
each cycle, conversions can be continuously performed
and read without a write cycle (see Figure 9). The D
IN
word remains unchanged from the last value written
into the device. If the device has not been written to
since power-up, the D
IN
word defaults to all 0s (S/D =
O/S = S0 = S1 = UNI = SLP = 0). At the end of a read
operation, a STOP condition may be given to start a new
conversion. At the conclusion of the conversion cycle,
the next result may be read using the method described
above. If the conversion cycle is not concluded and a
valid address selects the device, the LTC2309 gener-
S
CONVERSION NAP DATA INPUT ADDRESS CONVERSIONDATA
OUTPUT
W ACK WRITE7-BIT ADDRESS Sr R ACK
2309 F10
READ7-BIT ADDRESS P
Figure 10. Write, Read, START Conversion