ADS-112SLASH883 datasheet(4/6 Pages) ETC

4 / 6 page

ADS-112

CALIBRATION PROCEDURE

1. Connect the converter per Figures 3 and 4 and Tables 1 and

3 for the appropriate input range. Apply a pulse of 150

nanoseconds to the START CONVERT input (pin 16) at a

rate of 250kHz. This rate is chosen to reduce the flicker if

LED’s are used on the outputs for calibration purposes.

2. Zero Adjustments

Apply a precision voltage reference source between the

amplifier’s analog input and ground. Adjust the output of the

reference source per Table 2. For unipolar, adjust the zero

trimming potentiometer so that the output code flickers

equally between 0000 0000 0000 and 0000 0000 0001 with

COMP BIN (pin 18) tied high (straight binary) or between

1111 1111 1111 and 1111 1111 1110 with pin 18 tied low

(complementary binary).

For bipolar operation, adjust the potentiometer such that the

code flickers equally between 1000 0000 0000 and 1000

0000 0001 with pin 18 tied high (offset binary) or between

0111 1111 1111 and 0111 1111 1110 with pin 18 tied low

(complementary offset binary).

3. Full-Scale Adjustment

Set the output of the voltage reference used in step 2 to the

value shown in Table 2. Adjust the gain trimming potentiom-

eter so that the output code flickers equally between 1111

1111 1110 and 1111 1111 1111 for pin 18 tied high or between

0000 0000 0001 and 0000 0000 0000 for pin 18 tied low.

To confirm proper operation of the device, vary the precision

reference voltage source to obtain the output coding listed

in Table 4.

Figure 3. Typical ADS-112 Connection Diagram

Table 1. Input Range Selection

INPUT RANGE

INPUT PIN

TIE TOGETHER

±5v

Pin 19

Pin 20 to Pin 21

0 to +10V

Pin 19

Pin 20 to Ground

Table 3. Input Range (using external calibration)

INPUT RANGE

UNIT

0 to 10V, ±5

Ω

0 to 5V, ±2.5V

Ω

0 to +2.5V, ±1.25V

Ω

To Pin19

of ADS-112

–15V

+15V

For values of R1 and R2 refer to Table 3.

Ω

10k

Ω

ZERO/

OFFSET

ADJUST

SIGNAL

INPUT

GAIN

ADJUST

Ω

Figure 4. Optional Calibration Circuit

Table 2. Zero and Gain Adjust

Input

Zero Adjust

Gain Adjust

Range

+1/2 LSB

+FS – 1 1/2 LSB

0 to +10V

+1.22mV

+9.9963V

±5V

+1.22mV

+4.9963V

0.1µF

4.7µF

ADS-112

BIT 1 (MSB)

BIT 2

BIT 3

BIT 4

BIT 5

BIT 6

BIT 7

BIT 8

BIT 9

BIT 10

BIT 11

BIT 12 (LSB)

EOC

ENABLE (1-12)

ANALOG INPUT

START CONVERT

+5V

–15V

+15V

0.1µF

4.7µF

0.1µF

4.7µF

COMP BIN

0.1µF

4.7µF

21 +10V REF.

UNIPOLAR

OPERATION

BIPOLAR

OPERATION

+5V

Note: Always bypass pin 21 to ground

ADS-112/883 Datasheet(PDF) 4 Page - List of Unclassifed Manufacturers

ADS-112/883 Datasheet(HTML) 4 Page - List of Unclassifed Manufacturers

Html Pages

1 2 3 4 5 6

Datasheet Download

Link URL