TLC2543 is a 12-bit switched capacitor successive approximation analog-to-digital converter produced by Texas Instruments. It has three control inputs and can be easily connected to a microcomputer through a simple three-wire SPI serial interface. It is one of the best devices for 12 bit data acquisition system.

The connection between TLC2543 and peripheral circuits is simple, and the three control inputs are CS (chip selection), I/O clock and serial data input respectively. On-chip 14-channel multiplexer can select 1 1 input or any of three internal self-test voltages. Sample-and-hold is automatic, and EOC output becomes high level after conversion.

The main features of TLC2543 are as follows:

11analog input channels;

● Sampling rate of ●66ksps;

● The maximum conversion time is10 μ s;

●SPI serial interface;

● The maximum linear error is1LSB;

Low power supply current (typical1ma);

Low power-down mode current is 4 μ A. ..

The pin function is described as follows:

Ain0 ~ ain 10: analog input, selected by internal multiplexer. For 4. 1MHz I/O clock, the driving source impedance must be less than or equal to 50 Ω;

CS: chip selection terminal. Changing CS from high level to low level will reset the internal counter and control and enable data output, data input and I/O clock. When CS changes from low to high, data input and I/O clock will be prohibited within the set time;

Data input: serial data input. Serial data starts with MSB, and moves into 4-bit address at the first 4 rising edges of I/O clock, which is used to select the next analog input signal or test voltage to be converted, and then I/O clock inputs the remaining bits in turn;

Data output: three-state output end of A/D conversion result. When CS is high, this pin is in high impedance state; When CS is low, this pin is set to the corresponding logic level from the MSB value of the previous conversion result; EOC: end of conversion. After the falling edge of the last I/O clock, EOC changes from high level to low level and remains until the conversion is completed and the data is ready for transmission.

And: positive terminal of power supply and grounding;

Ref+, ref-: positive and negative reference terminals. Usually ref+ is connected to VCC and ref- is connected to GND. The maximum input voltage range depends on the voltage difference between the two ends;

I/O clock: clock input/output terminal.