Datasheet

TLC2543C, TLC2543I, TLC2543M
12-BIT ANALOG-TO-DIGITAL CONVERTERS
WITH SERIAL CONTROL AND 11 ANALOG INPUTS
SLAS079F – DECEMBER 1993 – REVISED NOVEMBER 2001
14
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PRINCIPLES OF OPERATION
data input
The data input is internally connected to an 8-bit serial-input address and control register. The register defines
the operation of the converter and the output data length. The host provides the data word with the MSB first.
Each data bit is clocked in on the rising edge of the I/O CLOCK sequence (see Table 2 for the data input-register
format).
Table 2. Input-Register Format
INPUT DATA BYTE
FUNCTION SELECT
ADDRESS BITS L1 L0 LSBF BIP
FUNCTION
SELECT
D7
(MSB)
D6 D5 D4 D3 D2 D1 D0
(LSB)
Select input channel
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN9
AIN10
0
0
0
0
0
0
0
0
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
Select test voltage
(V
ref+
– V
ref–
)/2
V
ref–
V
ref+
1
1
1
0
1
1
1
0
0
1
0
1
Software power down 1 110
Output data length
8 bits
12 bits
16 bits
0
X
†
1
1
0
1
Output data format
MSB first
LSB first (LSBF)
0
1
Unipolar (binary) 0
Bipolar (BIP) 2s complement 1
†
X represents a do not care condition.
data input address bits
The four MSBs (D7 – D4) of the data register address one of the 11 input channels, a reference-test voltage,
or the power-down mode. The address bits affect the current conversion, which is the conversion that
immediately follows the current I/O cycle. The reference voltage is nominally equal to V
ref+
– V
ref–
.