SPECIFIC FUNCTION
Initiate Conversion and
Output Data Using
Internal Clock
CS
1>0
R/C
0
BUSY EXT/INT DATACLK PWRD
1
0
Output
0
SB/BTC
x
OPERATION
Initiates conversion “n”. Data from conversion “n – 1”
clocked out on DATA synchronized to 16 clock
pulses output on DATACLK.
Initiates conversion “n”. Data from conversion “n – 1”
clocked out on DATA synchronized to 16 clock
pulses output on DATACLK.
Initiates conversion “n”.
Initiates conversion “n”.
Outputs a pulse on SYNC followed by data from
conversion “n” clocked out synchronized to external
DATACLK.
Outputs a pulse on SYNC followed by data from
conversion “n – 1” clocked out synchronized to
external DATACLK.
(1)
Conversion “n” in process.
Outputs a pulse on SYNC followed by data from
conversion “n – 1” clocked out synchronized to
external DATACLK .
(1)
Conversion “n” in process.
CS or R/C must be HIGH or a new conversion will
be initiated without time for acquisition.
Analog circuitry powered. Conversion can proceed.
Analog circuitry disabled. Data from previous
conversion maintained in output registers.
Serial data is output in Binary Two’s Complement format.
Serial data is output in Straight Binary format.
0
1>0
1
0
Output
0
x
Initiate Conversion and
Output Data Using External
Clock
1>0
0
1>0
0
1>0
1
1
1
1
1
1
1
Input
Input
Input
0
0
x
x
x
x
1>0
1
0
1
Input
0
x
0
0>1
0
1
Input
0
x
Incorrect Conversions
Power-Down
0
x
x
x
x
0
x
x
x
x
0>1
x
x
x
x
x
x
x
x
x
x
x
x
x
x
0
0
1
x
x
x
x
x
0
1
Selecting Output Format
NOTE: (1) See Figure 3b for constraints on previous data valid during conversion.
TABLE III. Control Truth Table.
DIGITAL OUTPUT
BINARY TWO’S COMPLEMENT
(SB/BTC LOW)
DESCRIPTION
Full-Scale Range
Least Significant Bit (LSB)
+Full Scale (FS – 1LSB)
Midscale
One LSB Below Midscale
–Full Scale
±10
305µV
±5
153µV
STRAIGHT BINARY
(SB/BTC HIGH)
BINARY CODE
HEX
CODE
ANALOG INPUT
±3.33V
102µV
0V to 10V
153µV
0V to 5V
76µV
0V to 4V
61µV
BINARY CODE
HEX
CODE
9.999695V 4.999847V 3.333231V 9.999847V 4.999924V 3.999939V
0V
–305µV
–10V
0V
–153µV
–5V
0V
–102µV
–3.333333V
5V
2.5V
2V
0111 1111 1111 1111
0000 0000 0000 0000
1111 1111 1111 1111
1000 0000 0000 0000
7FFF
0000
FFFF
8000
1111 1111 1111 1111
1000 0000 0000 0000
0111 1111 1111 1111
0000 0000 0000 0000
FFFF
8000
7FFF
0000
4.999847V 2.499924V 1.999939V
0V
0V
0V
TABLE IV. Output Codes and Ideal Input Voltages.
ADS7809
SBAS017C
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7
TI [ TEXAS INSTRUMENTS ]
