AD7982 datasheet(11/23 Pages) AD

11 / 23 page

Preliminary Technical Data

AD7982

Rev PrC | Page 11 of 23

Transfer Functions

The ideal transfer characteristic for the AD7982 is shown in

Figure 12 and Table 7.

100...000

100...001

100...010

011...101

011...110

011...111

ANALOG INPUT

+FS – 1.5 LSB

+FS – 1 LSB

–FS + 1 LSB

–FS

–FS + 0.5 LSB

Figure 12. ADC Ideal Transfer Function

Table 7. Output Codes and Ideal Input Voltages

Description

Analog Input

VREF = 5 V

Digital Output Code Hexa

FSR – 1 LSB

+4.999962 V

1FFFF1

Midscale + 1 LSB

+38.15 μV

00001

Midscale

0 V

00000

Midscale – 1 LSB

−38.15 μV

3FFFF

–FSR + 1 LSB

−4.999962 V

20001

–FSR

−5 V

200002

1 This is also the code for an overranged analog input (VIN+ − VIN− above VREF −

VGND).

2 This is also the code for an underranged analog input (VIN+ − VIN− below VGND).

TYPICAL CONNECTION DIAGRAM

Figure 13 shows an example of the recommended connection

diagram for the AD7982 when multiple supplies are available.

AD7982

REF

GND

VDD

IN–

IN+

VIO

SDI

SCK

SDO

CNV

3-WIRE INTERFACE

100nF

2.5V

μF2

V+

V-

1.8V TO 5V

REF1

0 TO VREF

2.7nF

V+

V-

VREF TO 0

2.7nF

1SEE REFERENCE SECTION FOR REFERENCE SELECTION.

2CREF IS USUALLY A 10μF CERAMIC CAPACITOR (X5R).

3SEE DRIVER AMPLIFIER CHOICE SECTION.

4OPTIONAL FILTER. SEE ANALOG INPUT SECTION.

ADA4841-2 or

note 3

Figure 13. Typical Application Diagram with Multiple Supplies

AD7982 Datasheet(PDF) 11 Page - Analog Devices

AD7982 Datasheet(HTML) 11 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Datasheet Download

Link URL