Rainbow Electronics MAX5811 - Manual (Page 10)

MAX5811
10-Bit Low Power 2-Wire Interface Serial,
Voltage-Output DAC
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write cycle must be repeated. Figure 6 shows two
example write data sequences. Read Data Format
In read mode (R/W = 1), the MAX5811 writes the con-
tents of the DAC register to the bus. The direction of
Table 3. Command Byte Definitions
SERIAL DATA INPUT
C3 C2 C1 C0 D9/PD1* D8/PD0* D7-D6
FUNCTION
1 1 0 0
DAC
DATA
DAC
DATA
DAC
DATA
Load DAC with 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 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
ignores 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 Power up the device.
0 1 X X 0 1 XX
Power-down mode 0. Power down device with output
floating.
0 1 X X 1 0 XX
Power-down mode 1. Power down device with output
terminated with 1k
Ω to GND.
0 1 X X 1 1 XX
Power-down mode 2. Power down device with output
terminated with 100k
Ω to GND.
S
MSB
MSB
A6 A5 A4 A3 A2 A1 A0 C3 C2 C1 C0 D9 D8 D7 D6
D5 D4 D3 D2 D1 D0 S1 S0 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 D9 and D8 write to the power-down registers (PD1 and PD0).
X = Don’t care.