Microchip Technology MCP4728EV Data Sheet
MCP4728
DS22187E-page 56
© 2010 Microchip Technology Inc.
FIGURE 7-5:
Example of Writing Fast Write Command for Various V
OUT
. V
REF
= V
DD
For All Channels.
1st Byte
2nd Byte
DAC A
Start
3rd Byte
Stop
S 1 1 0 0 A2 A1 A0 0 A 0 1 1 A2 A1 A0 0 1 A 0 1 1 A2 A1 A0 1 0 A
. . . . . . .
P
Address Byte
Write Command
Fast Mode
Next DAC Channels
V
OUT
V
REF
D
n
×
(
)
4096
---------------------------------- G
x
=
V
OU T
A
V
D D
4095
×
(
)
4096
------------------------------------
V
D D
4096
1
–
4096
---------------------
⎝
⎠
⎛
⎞
V
DD
1
1
4096
------------
–
⎝
⎠
⎛
⎞
V
DD
LS B
–
=
=
=
=
Dn for Channel A = 0FFF (hex) = 4095 (decimal)
(A) Channel A Output:
(B) Channel B Output:
Dn for Channel B = 07FF (hex) = 2047 (decimal)
V
OUT
B
V
DD
2047
×
(
)
4096
------------------------------------
V
DD
2048
1
–
4096
---------------------
⎝
⎠
⎛
⎞
V
DD
2
------------- 1
2
4096
------------
–
⎝
⎠
⎛
⎞
V
D D
2
-------------
LS B
–
=
=
=
=
(C) Channel C Output:
Dn for Channel C = 03FF (hex) = 1023 (decimal)
V
OU T
C
V
D D
1023
×
4096
----------------------------------
V
DD
1024
1
–
4096
---------------------
⎝
⎠
⎛
⎞
V
DD
4
------------- 1
4
4096
------------
–
⎝
⎠
⎛
⎞
V
DD
4
-------------
LS B
–
=
=
=
=
(D) Channel D Output:
Dn for Channel D = 01FF (hex) = 511 (decimal)
V
OU T
D
V
DD
511
×
4096
-------------------------------
V
DD
512
1
–
4096
------------------
⎝
⎠
⎛
⎞
V
DD
8
------------- 1
8
4096
------------
–
⎝
⎠
⎛
⎞
V
DD
8
-------------
LS B
–
=
=
=
=
DAC A Input Code =
001111-11111111
DAC B Input Code =
000111-11111111
DAC C Input Code =
000011-11111111
DAC D Input Code =
000001-11111111
The following example shows the expected analog outputs with the corresponding DAC input codes: