THS1209_14 Datasheet, PDF (20/34 Pages) Texas Instruments – 12-BIT, 2 ANALOG INPUT, 8 MSPS, SIMULTANEOUS SAMPLING ANALOG-TO-DIGITAL CONVERTER

THS1209
SLAS288B – JULY 2000 – REVISED DECEMBER 2002
ADC CONTROL REGISTERS
Control Register 0 (see Table 8)
BIT 11 BIT 10 BIT 9 BIT 8
0
0
TEST1 TEST0
BIT 7
SCAN
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BIT 6
DIFF1
BIT 5
DIFF0
BIT 4
CHSEL1
BIT 3
CHSEL0
BIT 2
PD
BIT 1
RES
BIT 0
VREF
Table 8. 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
RES
PD
CHSEL0,
CHSEL1
DIFF0, DIFF1
SCAN
TEST0,
TEST1
Vref select:
Bit 0 = 0 → The internal reference is selected.
Bit 0 = 1 → The external reference voltage is selected.
Reserved
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.
Channel select
Bit 3 and bit 4 select the analog input channel of the ADC. Refer to Table 9.
Number of differential channels
Bit 5 and bit 6 contain information about the number of selected differential channels. Refer to Table 9.
Autoscan enable
Bit 7 enables or disables the autoscan function of the ADC. Refer to Table 9.
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 10 for selection of the three different test voltages.
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