MCP4706 Datasheet, PDF (50/86 Pages) Microchip Technology – 8-/10-/12-Bit Voltage Output Digital-to-Analog Converter with EEPROM and I2C Interface

MCP4706/4716/4726
6.1 Write Volatile DAC Register
(C2:C0 = ‘00x’)
This command is used to update the volatile DAC
Register value and the two Power-down configuration
bits (PD1:PD0). This command is typically used for a
quick update of the analog output by modifying the
minimum parameters. The EEPROM values are not
affected by this command.
Figure 6-1 shows an example of the command format,
where a stop bit completes the command.
The volatile DAC register and Power-down
configuration bits are updated with the written date at
the completion of the ACK bit (falling edge of SCL).
After this ACK bit, the I²C Master should generate a
Stop bit or the I²C Master can repeat the 2nd (2
command bits + 2 power down bits + 4 data bits
(b11:b08)) and the 3rd byte (8 data bits (b07:b00)).
Repeating the 2nd and 3rd bytes allows a continuous
command where the volatile DAC register can be
updated without the communication overhead of the
device addressing byte (1st byte).
The device updates the V_OUT at the falling edge of the
Acknowledge pulse of the 3rd byte.
Start bit
Read/Write bit (Write)
ACK bit ⁽³⁾
ACK bit ⁽³⁾
ACK bit ⁽³⁾ Stop bit
S
R/W A
A
AP
SDA
1 1 0 0 A2 A1 A0 0 0 0 0 PD1 PD0 b11 b10 b09 b08 0 b07 b06 b05 b04 b03 b02 b01 b00 0
SCL
Device Addressing
Command Power Data bits (4 bits)
bits
Down
bits
Data bits (8 bits)
Data bits (12 bits)
b11 b10 b09 b08 b07 b06 b05 b04 b03 b02 b01 b00
MCP4726 D11 D10 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00
MCP4716 D09 D08 D07 D06 D05 D04 D03 D02 D01 D00 X X
MCP4706 X X X X D07 D06 D05 D04 D03 D02 D01 D00
Note 1
Note 2
Note 1: The device updates V_OUT at the falling edge of the SCL at the end of this ACK pulse.
2: The 2nd - 3rd bytes can be repeated after the 3rd byte by continued clocking before issuing Stop bit.
3: ACK bit generated by MCP47X6.
Legend:
X = don’t care
D11:D00 = 12-bit data for MCP4726 device
D09:D00 = 10-bit data for MCP4716 device
D07:D00 = 8-bit data for MCP4706 device
FIGURE 6-1:
Write Volatile DAC Register Command.
DS22272A-page 50
© 2011 Microchip Technology Inc.