LTC2345-18

15

234518f

For more information www.linear.com/LTC2345-18

conFiguraTion Tables

Table 1a. SoftSpan Configuration Table. Use This Table with Table 1b to Choose Independent Binary SoftSpan Codes SS[2:0] for Each

Channel Based on Desired Analog Input Range. Combine SoftSpan Codes to Form 24-Bit SoftSpan Configuration Word S[23:0]. Use

Serial Interface to Write SoftSpan Configuration Word to LTC2345-18, as shown in Figure 19

BINARY SoftSpan CODE

SS[2:0]

ANALOG INPUT RANGE

FULL SCALE RANGE

BINARY FORMAT OF

CONVERSION RESULT

111

Two’s Complement

110

Two’s Complement

101

Straight Binary

100

Straight Binary

011

Two’s Complement

010

Two’s Complement

001

Straight Binary

000

Channel Disabled

Channel Disabled

All Zeros

Table 1b. Reference Configuration Table. The LTC2345-18 Supports Three Reference Configurations. Analog Input Range Scales with

REFERENCE CONFIGURATION

BINARY SoftSpan CODE

SS[2:0]

ANALOG INPUT RANGE

Internal Reference with

Internal Buffer

2.048V

4.096V

111

±4.096V

110

±4V

101

0V to 4.096V

100

0V to 4V

011

±2.048V

010

±2V

001

0V to 2.048V

External Reference with

Internal Buffer

(REFIN Pin Externally

Overdriven)

1.25V

(Min Value)

2.5V

111

±2.5V

110

±2.441V

101

0V to 2.5V

100

0V to 2.441V

011

±1.25V

010

±1.221V

001

0V to 1.25V

2.2V

(Max Value)

4.4V

111

±4.4V

110

±4.297V

101

0V to 4.4V

100

0V to 4.297V

011

±2.2V

010

±2.148V

001

0V to 2.2V