User manual

MCP4728 Evaluation Board User’s Guide
DS51837A-page 44 © 2009 Microchip Technology Inc.
Write V
REF
, Gain, and Power-Down Select Bits (Note 4)
1 0 0 Not Used Write Reference
(V
REF
) selection
bits to Input Regis-
ters
This command writes reference (V
REF
) selection bits of each
channel.
1 1 0 Not Used Write Gain selec-
tion bit to Input
Registers
This command writes Gain selection bits of each channel.
1 0 1 Not Used Write Power-Down
bits to Input Regis-
ters
This command writes Power-Down bits of each channel.
TABLE C-1: WRITE COMMAND TYPES (CONTINUED)
Command Field
Write
Function
Command Name Function
C2 C1 C0 W1 W0
Note 1: The analog output is updated when LDAC
pin is (or changes to) “Low”. UDAC bit is not used for this
command.
2: The DAC output is updated when LDAC
pin or UDAC bit is “Low”.
3: The device starts writing to the EEPROM on the acknowledge clock pulse of the last channel. The device
does not execute any command until RDY/BSY
bit comes back to “High”.
4: The input and output registers are updated at the acknowledge clock pulse of the last byte. The update
does not require LDAC
pin or UDAC bit conditions. EEPROM is not affected.