Rainbow Electronics MAX5812 - Manual (Page 10)

MAX5812
12-Bit Low-Power, 2-Wire, Serial
Voltage-Output DAC
10 ______________________________________________________________________________________
Table 3. Command Byte Definitions
SERIAL DATA INPUT
C3 C2 C1 C0 D11/PD1* D10/PD0* D9–D8
FUNCTION
1 1 0 0
DAC
DATA
DAC
DATA
DAC
DATA
Load DAC with a new data from the following data byte
and update DAC output simultaneously as soon as data
is available from the serial bus. The DAC and input
registers are updated with the new data.
1 1 0 1
DAC
DATA
DAC
DATA
DAC
DATA
Load input register with the data from the following data
byte. DAC output remains unchanged.
1 1 1 0
DAC
DATA
DAC
DATA
DAC
DATA
Load input register with data from the following data byte.
Update DAC output to the previously stored data.
1 1 1 1 X X XX
Update DAC output from input register. The device will
ignore any new data.
1 0 X X X X XX
Read data request. Data bits are ignored. The contents of
the DAC register are available on the bus.
0 1 X X 0 0 XX Powers up device.
0 1 X X 0 1 XX
Power-down mode 0. Powers down device with output
floating.
0 1 X X 1 0 XX
Power-down mode 1. Powers down device with output
terminated with 1k
Ω to GND.
0 1 X X 1 1 XX
Power-down mode 2. Powers down device with output
terminated with 100k
Ω to GND.
S
MSB
MSB
A6 A5 A4 A3 A2 A1 A0 C3 C2 C1 C0 D11 D10 D9 D8
D7 D6 D5 D4 D3 D2 D1 D0 P
R/W ACK
ACK
ACK
LSB MSB LSB
LSB
S
MSB
A6 A5 A4 A3 A2 A1 A0 C3 C2 X X PD1 PD0 X X P R/W ACK ACK
LSB
EXAMPLE WRITE DATA SEQUENCE
EXAMPLE WRITE TO POWER-DOWN REGISTER SEQUENCE
MSB
LSB
Figure 6. Example Write Command Sequences
*When C3 = 0 and C2 = 1, data bits D11 and D10 write to the power-down registers (PD1 and PD0).
X = Don’t care.