THS12082 Datasheet, PDF (17/38 Pages) Texas Instruments – 12-BIT, 8 MSPS, SIMULTANEOUS SAMPLING ANALOG-TO-DIGITAL CONVERTERS

THS12082
12-BIT, 8 MSPS, SIMULTANEOUS SAMPLING ANALOG-TO-DIGITAL CONVERTERS
ADC control registers
control register 0 (see Table 8)
–
–
BIT 9
BIT 8
–
–
TEST1
TEST0
BIT 7
SCAN
SLAS271 – MAY 2000
BIT 6
DIFF1
BIT 5
DIFF0
BIT 4
BIT 3
CHSEL1 CHSEL0
BIT 2
PD
BIT 1
MODE
BIT 0
VREF
Table 9. Control Register 0 Bit Functions
BITS
0
1
2
3, 4
5,6
7
8,9
RESET
VALUE
0
0
0
0,0
1,0
0
0,0
NAME
FUNCTION
VREF
Vref select:
Bit 0 = 0 → The internal reference is selected.
Bit 0 = 1 → The external reference voltage is selected.
MODE
Continuous conversion mode/single conversion mode
Bit 1 = 0 → Continuous conversion mode is selected.
An external clock signal is applied to the CONV_CLK input in this mode. With every falling edge of the
CONV_CLK signal a new converted value is written into the FIFO.
Bit 1 = 1 → Single conversion mode is selected.
In this mode, the CONV_CLK input functions as a CONVST input. A single conversion is initiated on the
THS12082 by pulsing the CONVST input. On the falling edge of CONVST, the sample and hold stages of
the selected analog inputs are placed into hold simultaneously, and the conversion sequence for the
selected channels is started. The signal DATA_AV (data available) becomes active when the trigger
condition is satisfied.
PD
Power down.
Bit 2 = 0 → The ADC is active.
Bit 2 = 1 → Power down
The reading and writing to and from the digital outputs is possible during power down. It is also possible to
read out the FIFO.
CHSEL0,
CHSEL1
Channel select
Bit 3 and bit 4 select the analog input channel of the ADC. Refer to Table 10.
DIFF0, DIFF1 Number of differential channels
Bit 5 and bit 6 contain information about the number of selected differential channels. Refer to Table 10.
SCAN
Autoscan enable
Bit 7 enables or disables the autoscan function of the ADC. Refer to Table 10.
TEST0,
TEST1
Test input enable
Bit 8 and bit 9 control the test function of the ADC. Three different test voltages can be measured. This
feedback allows the check of all hardware connections and the ADC operation.
Refer to Table 11 for selection of the three different test voltages.
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