
LTC2754
14
2754f
OPERATION
Table 1. Command Codes
CODE
COMMAND
READBACK POINTER–
CURRENT INPUT WORD W0
READBACK POINTER–
NEXT INPUT WORD W+1
C3
C2
C1
C0
0010
Write Span DAC n
Set by Previous Command
Input Span Register DAC n
0011
Write Code DAC n
Set by Previous Command
Input Code Register DAC n
0100
Update DAC n
Set by Previous Command
DAC Span Register DAC n
0101
Update All DACs
Set by Previous Command
DAC Code Register DAC A
0110
Write Span DAC n
Update DAC n
Set by Previous Command
DAC Span Register DAC n
0111
Write Code DAC n
Update DAC n
Set by Previous Command
DAC Code Register DAC n
1000
Write Span DAC n
Update All DACs
Set by Previous Command
DAC Span Register DAC n
1001
Write Code DAC n
Update All DACs
Set by Previous Command
DAC Code Register DAC n
1010
Read Input Span Register DAC n
Input Span Register DAC n
1011
Read Input Code Register DAC n
Input Code Register DAC n
1100
Read DAC Span Register DAC n
DAC Span Register DAC n
1101
Read DAC Code Register DAC n
DAC Code Register DAC n
1111
No Operation
Set by Previous Command
DAC Code Register DAC n
–
System Clear
–
DAC Span Register DAC A
–
Initial Power-Up or Power Interupt
–
DAC Span Register DAC A
Codes not shown are reserved–do not use
Table 2. Address Codes
A3
A2
A1
A0
n
000
×
DAC A
001
×
DAC B
010
×
DAC C
011
×
DAC D
111
×
All DACs (Note 1)
Codes not shown are reserved–do not use.
× = Don’t Care.
Note 1. If readback is taken using the All DACs address, the LTC2754
defaults to DAC A.
Table 3. Span Codes
S3
S2
S1
S0
SPAN
×
0
Unipolar 0V to 5V
×
0
1
Unipolar 0V to 10V
×
0
1
0
Bipolar –5V to 5V
×
0
1
Bipolar –10V to 10V
×
1
0
Bipolar –2.5V to 2.5V
×
1
0
1
Bipolar –2.5V to 7.5V
Codes not shown are reserved–do not use.
× = Don’t Care.