5V, 8-Channel, Serial, 12-Bit ADCs

with 3V Digital Interface

12

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Table 2. Control-Byte Format

Table 3. Channel Selection in Single-Ended Mode (SGL/D

DIIF

F = 1)

SEL1

SEL0

0

0

0

CH4

CH5

SEL2

CH6

CH7

GND

–

1

0

0

–

+

0

0

1

–

+

1

0

CH0

+

1

–

+

0

1

CH1

0

+

–

1

1

CH3

0

+

–

0

1

CH2

1

+

–

1

1

1

+

–

Table 4. Channel Selection in Differential Mode (SGL/D

DIIF

F = 0)

SEL1

SEL0

0

0

0

CH4

CH5

SEL2

CH6

CH7

0

0

1

–

+

0

1

0

+

–

0

1

CH0

+

1

+

–

1

0

CH1

–

0

–

+

1

0

CH3

1

+

–

1

1

CH2

0

–

+

1

1

1

–

+

PD0

Bit 0

(LSB)

SGL/DIF

Bit 2

PD1

Bit 1

UNI/BIP

Bit 3

SEL 0

Bit 4

Bit 7

(MSB)

SEL 1

SEL 2

START

Bit 5

Bit 6

1 = unipolar, 0 = bipolar. Selects unipolar or bipolar conversion mode. In unipolar mode, an

1 = single ended, 0 = differential. Selects single-ended or differential conversions. In single-

ended mode, input signal voltages are referred to GND. In differential mode, the voltage dif-

ference between two channels is measured. (Tables 3 and 4.)

Selects clock and power-down modes.

PD1

PD0

Mode

00

01

10

Internal clock mode

11

External clock mode

These three bits select which of the eight channels is used for the conversion

(Tables 3 and 4).

The first logic 1 bit after CS goes low defines the beginning of the control byte.

UNI/BIP

3

SGL/DIF

2

PD1

PD0

1

0 (LSB)

SEL2

SEL1

SEL0

6

5

4

START

7 (MSB)

Description

Name

Bit