LTC1291 Linear Technology, LTC1291 Datasheet - Page 8

• Manufacturer Part Number: LTC1291
• Description: Single Chip 12-Bit Data Acquisition System
• Manufacturer: Linear Technology

D
LTC1291
* STOPPING THE CLOCK WILL HELP REDUCE POWER CONSUMPTION
D
DATA (D
select (CS) signal. After CS falls the LTC1291 looks for a
start bit. After the start bit is received a 4-bit input word is
shifted into the D
and starts the conversion. After one null bit, the result of
D
CLK
8
A
D
OUT
CLK
CLK
MSB-FIRST DATA (MSBF = 1)
D
OUT
CS
CS CAN BE BROUGHT HIGH ONCE D
D
OUT
CS
LSB-FIRST DATA (MSBF = 0)
IN
CS
IN
IN
PPLICATI
HI-Z
HI-Z
IN
HI-Z
START
START
START
/D
OUT
SGL/
DIFF
SGL/
DIFF
SGL/
DIFF
). Data transfer is initiated by a falling chip
ODD/
SIGN
ODD/
SIGN
O
ODD/
SIGN
IN
input which configures the LTC1291
U
IN
MSBF
MSBF
HAS BEEN CLOCKED IN
t
t
MSBF
SMPL
SMPL
S
PS
PS
PS
I FOR ATIO
U
(Example: Differential Inputs (CH0 + , CH1 – ) and MSB-First Data)
B11
B11
B11
W
REQUEST POWER SHUTDOWN
(Example: Differential Inputs (CH0 + , CH1 – ))
Power Shutdown Operating Sequence
DATA NOT VALID
t
CONV
t
CONV
U
Operating Sequence
t
t
CYC
CYC
DON'T CARE
the conversion appears MSB-first on the D
conversion result is output, bit by bit, as the conversion is
performed. At the end of the data exchange CS should be
brought high. This resets the LTC1291 in preparation for
the next data exchange.
B1
DON'T CARE
B1
DON'T CARE
B0
B0
B0
B1
FILLED WITH
ZEROES
FILLED WITH ZEROES
SHUTDOWN*
HI-Z
NEW CONVERSION BEGINS
START
SGL/
DIFF
OUT
ODD/
SIGN
B11
DON'T
FILLED WITH
CARE
MSBF
line. The
ZEROES
PS
DON’T
CARE
1291 AI04
1291 AI03